C2-028.840.01.09.02.pdf
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SOMATOM Definition CT
Troubleshooting Guide Gantry Instructions for Troubleshooting
© Siemens, 2006
07740777
© Siemens, 2006 - For internal use only - All documents may only be used by authorized personnel for rendering services on Siemens Healthcare Products. Any document in electronic form may be printed once. Copy and distribution of electronic documents and hardcopies is prohibited. Offenders will be liable for damages. All other rights are reserved.
Print No.: Replaces:
C2-028.840.01.09.02 C2-028.840.01.08.02
English Doc. Gen. Date: 08.11 H CX CS SD CR-CT n.a.
2006
2
Copyright / Version / Disclaimer
1Copyright / Version / Disclaimer
Copyright “© Siemens, 2006“ refers to the copyright of a Siemens entity such as Siemens Aktiengesellschaft - Germany, Siemens Shenzhen Magnetic Resonance Ltd. - China, Siemens Shanghai Medical Equipment Ltd. - China, Siemens Medical Solutions USA Inc. - USA and/or Siemens Healthcare Diagnostics Inc. - USA. Document Version Siemens reserves the right to change its products and services at any time. In addition, manuals are subject to change without notice. The hardcopy documents correspond to the version at the time of system delivery and/or printout. Versions to hardcopy documentation are not automatically distributed. Please contact your local Siemens office to order current version or refer to our website http://www.healthcare.siemens.com. Disclaimer Siemens provides this documentation “as is“ without the assumption of any liability under any theory of law. The service of equipment described herein is to be performed by qualified personnel who are employed by Siemens or one of its affiliates or who are otherwise authorized by Siemens or one of its affiliates to provide such services. Assemblers and other persons who are not employed by or otherwise directly affiliated with or authorized by Siemens or one of its affiliates are not entitled to use this documentation without prior written authority.
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0Table of Contents
1 _______ General ________________________________________________________ 7 Safety information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Safety warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Information for switching off the gantry power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Service Push-Button S1 in PDC-A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Safety bolts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Data ring protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2 _______ XRS __________________________________________________________ 15 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Definitions and abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15 15 15 15 16
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Problem isolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Generator oscillator procedure (GenOSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Flowchart for HV Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17 17 17 18
XDC/Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 XDC/Tube Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 XDC/Tube test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 High voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG high voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Check/adjust the tube oil pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HV plugs with arcing tracks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HV plug installation at HV sockets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . High voltage tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21 21 23 26 28 29
Filament . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 TSG filament . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Filament . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Anode rotation (RAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 TSG Anode Rotation (RAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Single pulse test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Single pulse test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Single pulse test diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Arcing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 XRS hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Switching on status display of XGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Measuring points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Measuring points D700, D701, D702, D703 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 LED´s on D700, D701, D702, D703 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3 _______ DMS__________________________________________________________ 56 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
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Table of Contents Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Definitions and abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
56 56 57 57
TSG Image Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG strong rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG sporadic strong rings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG weak rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG sporadic weak rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG rings in outer slices only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG Streak artifacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG Dual Source problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG Spatial Resolution (bad MTF results) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG other artifacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tests for Image Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
58 58 59 60 62 63 63 64 65 67 68 69
TSG DMS Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 TSG DMS Power path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 TSG UHR mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Additional Tests & Hints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Storage of Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Environmental Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hints for defective channel detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Separate between module and other components . . . . . . . . . . . . . . . . . . . . . . . . . . How to interpret the physicist’s line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
96 96 96 97 98 99
4 _______ Datalink ______________________________________________________ 100 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Definitions and abbreviations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General: Receivers with Revision IRS Receiver/s. . . . . . . . . . . . . . . . TSG data quality at Tx module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG data quality at RX modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG sporadic errors in link DCON -> IRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 1 (checking). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 2 (debugging) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Step 3 (localizing) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
103 103 105 106 107 108 108 109
Tests for data transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Cleaning a fiber optic cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Data Link Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . How to check the transmitting antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Measuring the fiber optic signal along the link. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Check the electrical RF signals at the Rx modules . . . . . . . . . . . . . . . . . . . . . . . . . Check the quality of data signal (jitter) at the G-REC input . . . . . . . . . . . . . . . . . . .
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5 _______ Fastlink ______________________________________________________ 121 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Definitions and abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General: Receivers with Revision UMAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG for connection UMAR -> UMAS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG data quality at Tx modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . TSG data quality at Rx modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tests for data transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
124 124 125 127 130 132 133 134
6 _______ Rotating Gantry _______________________________________________ 138 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Definitions and abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
138 138 138 138 138
CAN Bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 TSG CAN bus (rotating part). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 TSG CAN bus to XGS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 Stop report loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 TSG stop report loop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Rotating controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 DOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 COC (Tube collimator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 System Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 DOM functional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 X-ray timeout test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
7 _______ Stationary Gantry______________________________________________ 154 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Definitions and abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
154 154 154 154 154
CANopen Bus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 TSG CAN open bus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 Stationary controller tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Master stationary (MAS) test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gantry panel control (GPC) test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rotation control (ROT) test (only max. speed limit test, 0.33 sec.). . . . . . . . . . . . .
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Table of Contents
8 _______ Cooling System _______________________________________________ 160 Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Water Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 Air Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168
9 _______ Changes to Previous Version ____________________________________ 174 10 ______ Index ________________________________________________________ 175
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© Siemens, 2006 For internal use only
General
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1-
Safety information
1General
0
Only qualified and system-trained service staff is allowed to perform CT system installation, service , maintenance and quality assurance. Ensure that the most recent version of the service documentation is available. To avoid any risk of injury to persons and/or damage to the system read and observe the General Safety Notes (TD00-000.860.01.xx.xx). Please read and observe the Productspecific safety notes (C2-028.860.01.xx.xx) which include very important safety-related information as well as information about handling of screws and nuts, use of Loctite and instructions for torque wrenches. You will find the following information in the “Product-specific safety notes.”
• Safety information related to the method of risk management (C2-028.860.01 / General safety warnings).
• General safety information such as the handling of service documentation, CT system training request, X-ray protection, electrical protection, service tools....(C2-028.860.01 / General safety information).
• General safety information about working in the gantry with the power off/on (C2-028.860.01 / Working in the gantry with gantry power off).
• Use of the patient table as lifting device for gantry part replacement (C2-028.860.01 / Usage of patient table as lifting device).
• Laser products (C2-028.860.01 / Laser Products). • Attachment of screws and nuts, use of Loctite, adjustment instructions for the torque wrench (C2-028.860.01 / Screw Connections).
Safety warnings
0
The following safety information is an extract of the information in the Product-specific safety notes (C2-028.860.01.xx.xx) (C2-028.841.01 / Safety information). It is mandatory to read and observe the safety information described below.
CAUTION
[ hz_serdoc_F13G02U01M04 ]
Flammable sprays. Risk of inflammation! ¹ Only use approved and recommended cleaning agents as described. CAUTION
[ hz_serdoc_F13G07U01M01 ]
Handling parts of the system that may have come into contact with patients may lead to infection caused by blood-borne pathogens. Infection caused by blood-borne pathogens! ¹ Take appropriate precautions against exposure to blood-borne pathogens (e.g. wear gloves).
© Siemens, 2006 For internal use only
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SOMATOM Definition
8
General WARNING
[ hz_serdoc_F13G01U13M02 ]
High voltages and/or mechanical movements (e.g. gantry rotation) may lead to accidents and injuries when opening system covers. Risk of accident and injury! ¹ Only authorized service personnel is allowed to open system covers. CAUTION
[ hz_serdoc_F13G01U03M01 ]
Not following X-rays protective regulations may lead to radiation exposure to you and/or other persons. Risk of radiation exposure! Observe radiation protection regulations when X-rays are switched on, e.g. : ¹ Never work inside the gantry room. ¹ Do not leave the system unattended. ¹ Make sure there isn't anyone inside the gantry room. ¹ Make sure that no person can enter the gantry room unnoticed (e.g. lock doors if necessary) . WARNING
[ hz_serdoc_F13G01U05M03 ]
Dangerous voltages are present when the system is switched on. Dangerous voltages may be present even when the system is switched off due to capacity power. Risk of electric shock! ¹ Observe power-off instructions and discharge wait times (allow at least five minutes discharge time after the last scan for all involved HV and UDC/UPS parts). ¹ Secure the system against unintended switch-on (e.g. block breaker and/or mark breaker against switch on). ¹ Ensure via measurements that all voltages are switched off. ¹ Connect the stationary and rotating parts of the gantry to a protective conductor prior to working in the gantry. CAUTION
[ hz_serdoc_F13G01U06M01 ]
Rotating parts are exposed when gantry covers are opened. Risk of injury! ¹ Maintain a safe distance and ensure that objects do not come in contact with rotating parts.
SOMATOM Definition
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General
9 CAUTION
[ hz_serdoc_F13G05U01M04 ]
Unfixed parts/cables during gantry rotation. Risk of accident and injury! ¹ Make sure that all parts and cables are mounted properly before starting rotation. CAUTION
[ hz_serdoc_F13G02U01M01 ]
Temperature of tube and/or tube cooling device parts may be above 70C (with Straton up to 130C). Risk of burns! ¹ Avoid contact with oil and exposed parts of X-ray tube and cooling device. ¹ Wait until tube and cooling device parts are chilled down.
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SOMATOM Definition
10
General
Information for switching off the gantry power
1.1
• Switch off system (Click and select in the user main menu to switch off the system automatically after shut down). Additionally, switch off the gantry power using service pushbutton S1 in PDC-A (C2-028.841.01 / Service Push-Button S1 in PDC-A). Secure against unintended switch-on.
NOTE
SOMATOM Definition
Read and observe the safety information in the “Product-specific safety notes” prior to performing service work in the gantry. If the gantry power is switched off for service work, always secure it against accidental switch on.
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General
11
Service Push-Button S1 in PDC-A
Fig. 1:
1.2
Service push-button S1
Pos. 1
Service push-button S1
Pos. 2
Push-button
If S1 is pressed the complete power supply for the gantry is switched off. As well as the power input to the DC-Link of XGS_A and XGS_B. The circuit breakers F2, F3, F5, F6, F7, F11 in PDC_A and F2 in PDC_B get tripped through an additional shunt trip attached to the circuit breakers. For normal operation the circuit breakers have to be reset manually.
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SOMATOM Definition
12
General
Safety bolts
1.3
• Front safety bolt -> located at bottom right gantry front
Fig. 3: Fig. 2:
Rotation safety lock - lock position
Rotation safety lock - unlock position
• Unlock position of gantry front safety bolt (item 1) • Lock position of gantry safety bolt (item 2). • Back safety bolt
Fig. 4:
Rotation safety lock - back
• Back rotation safety bolt (item 1) located between XGS A and HV-tank A at the back of the gantry.
• Lift bolt and turn it 90 degrees to bring it into the lock or unlock position. ¹ Make sure that the bolt is really at the correct (lock/unlock) position. If the bolt accidentlally moves into the lock position during rotation, the gantry may be damaged.
SOMATOM Definition
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General
13
• Principle function of back safety bolt
Fig. 5:
Back safety block - unlock position
Fig. 6:
Back safety block - lock position
• Unlock position of gantry front safety bolt (left image, item 1). From lock position (item 2), lift the bolt in the direction of the arrow and rotate it 90 degrees to bring the bolt into the unlock position (item 1).
• Lock position of gantry safety bolt (right image, item 2). From unlock position (item 1), lift the safety bolt and rotate it 90 degrees to bring it into the lock position (item 2).
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SOMATOM Definition
14
General
Data ring protection
1.4
• Installing data ring protection
Fig. 7:
Data ring protection
• Install the 2 data ring protectors (e.g. item 1) before working at the gantry front. - 2 Plexiglas protectors are necessary to cover a larger area on the data ring. - Attach them to the stationary data ring. - Do not forget to remove the protectors before starting gantry rotation.
SOMATOM Definition
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XRS General
2XRS
15 20
Safety
0
WARNING
[ hz_serdoc_F13G01U12M03 ]
Avoid accident and injury or damage to parts. Risk of accident and injury! ¹ Read and observe the safety information contained in the “General” section of this document and/or the “Product specific safety notes”.
Notes
0
This section contains information on isolating XRS problems
• Section “General” -> General information.. • Section “Overview” -> XRS Information. • • Section “High voltage” -> High voltage TSG followed by high voltage test descriptions.
• • • •
Section ”Filament” -> Filament TSG followed by filament test description.. Section ”Anode rotation” -> Anode rotation TSG followed by RAC test description.. Section ”XRS hints” -> XRS hints. Section ”Measuring point” -> Table of LEDs and measuring points on XGS/XRS.
Definitions and abbreviations Tab. 1
0
Definitions and abbreviations
Term
Definition / Abbreviation
XDC
X-ray deflection control
XGR
X-ray generator, rotating
XGS
X-ray generator, stationary
XRS
X-ray system
XRT
X-ray tube
XTA
X-ray tube assembly
XTC
X-ray tube cooling
MVT
Middle voltage transmission
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SOMATOM Definition
16
XRS Term
Definition / Abbreviation
HVT
High voltage tank
TSG
Troubleshooting guide
Prerequisites
0
Documents n.a Tools and auxiliary equipment
• Standard tool kit • HV test plugs
SOMATOM Definition
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XRS
17
Overview
2.1
The XRS section contains information on possible XRS tests and the corresponding troubleshooting guides. In the SOMATOM Definition, troubleshooting always starts by calling up the EventLog and searching for the relevant error message. Follow the instructions given in this error message for troubleshooting. In some cases, the error message will link you to troubleshooting instructions as described in this document. This link is normally used if the troubleshooting instructions are too complex or images are needed for troubleshooting. Additionally, read the information which is stored in the tube history (Local Service ->Report). This information can always be useful in case of XRS problems.
Problem isolation
0
Principle problem isolation in case of XRS problems 1. Find relevant error message in Eventlog NOTE
The XGR and XGS assemblies are continuously communicating using the CAN bus after the system is switched on. For this reason, 2 error messages are usually sent to the logbook after XRS problems. Always check both (XGS/XGR) error messages when troubleshooting.
2. Follow the instructions given in the error message text for troubleshooting ¹ The information provided in the error message will guide you in finding the problem. In some cases, you will be linked to this Test and Troubleshooting instructions, # C2-028.840.01.... In this case, follow the relevant troubleshooting instructions described in this document.
Generator oscillator procedure (GenOSC)
0
Generator oscillator adaptation (Gen-Osc) is an automatic program. The purpose of the program is to adapt the inverter frequencies. The program performs very short scans with different inverter frequencies to find the minimum resonance point. This value is stored to D700 in XGS. The frequency adaptation procedure must run successfully; otherwise, XRS errors such as UT too high or UT max errors (e.g XRS_83 error) may abort scanning. The same errors may appear if parts of the oscillating circuit (MV cable, XGS_PDC_Control, HVT / MVT) have been replaced without performing GenOSC after exchange. For this reason, always use the relevant guided tour after part replacement.
NOTE
© Siemens, 2006 For internal use only
If GenOsc fails because of arcing, try using dummy plugs (i.e. test plugs for HVT) and perform GenOsc again with dummy plugs installed.
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SOMATOM Definition
18
XRS
Flowchart for HV Troubleshooting
0
The flowchart (Fig. 8 / p. 19) gives a guideluine how to deal with tube arcings and represents the algorithm behind the tool “SOMATOM Definition HV Troubleshooting”. For more information regarding this tool, see the documentation for CT016/09/R.
SOMATOM Definition
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XRS
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19
HV Troubleshooting Flowchart SOMATOM Definition
Fig. 8:
20
XRS
XDC/Tube
2.2
XDC/Tube Test
0
INIT Tests: During INIT, all XRT drivers of the XDC (outputs on X13 and X14) are tested in 2 steps. The first step is an isolation check for detecting short circuits between the output wires and ground or power (230 V). This step can detect defective driver gates within the XDC as well. The second step activates the drivers and can detect short circuits between the output wires or broken wires. The INIT tests have failed if any warning or error message occurs in the Eventlog during step 1 or 2, or if the requested currents in step 2 cannot be reached. XDC/Tube Self-Test within Service SW: The XDC/Tube self-test is basically the same as the INIT test. Depending on the actual system state, the XDC/Tube self-test tolerates some problems. So, if the XDC/Tube self-test fails, switch the gantry off/on to initialize an INIT test. Test results: If the test fails, it results in error message " CT_DCA/B 31" where the parameters give some information on which part of the test failed. In addition to this information, there can be additional errors or warnings which indicate the error. Follow the instructions in the warning/error message for troubleshooting Usage of the tests: The XDC/Tube self-test can help detect problems in the output drivers of the XDC, problems within cabling, or problems within the tube. The test can be helpful if the XDC has aborted scans with the error message "CT_DCA/B 51 ..." or "CT_DCA/B 50", especially if parameter 3 is 0x00, 0x01, 0x04, 0x05, 0x08, 0x09, 0x12, 0x17, 0x1D, 0x1E or 0x1F. Be aware that any of these errors can happen during arcing as well, without any real HW problem within the XDC or the tube. If the INIT tests fail, you have a problem in the XDC, cabling, or the tube. If any additional error or warning message occurs in the Eventlog during INIT, it can be used to help detect where the problem is located. You can disconnect the cable on the XDC (X13 and X14) and/or the tube (X8 and X4) and then repeat the INIT test. When the additional errors/warnings disappear, you have disconnected the faulty part from the XDC. Remark: Test can be used if the system is in or is not in stand-by status.
XDC/Tube test
0
XDC/Tube test Performing the filament test 1. Select Local Service > Test Tools > Tube/Generator 2. Select XDC/Tube. 3. Click GO and follow the instructions in the dialog. The test is terminated automatically.
SOMATOM Definition
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XRS
21
High voltage
2.3
TSG high voltage
0
The following high voltage TSG has to be used in case of high voltage problems. The TSG starts at the XRT (X-ray tube) and provides guidance through the HV related components.
Tab. 2
NOTE
XRS components cannot be exchanged from system A to system B or vice versa for troubleshooting.
NOTE
Always use new silicon insulators at the HV sockets ((HV plug installation at HV sockets / p. 28)) as well as new silicon disks at the HVT when installing the cable plugs or the test plugs.
High voltage TSG
Step
Action
1
• Check Eventlog for UT max and /or UT too high errors (e.g XRS_83) or arcing problem (XRS_68).
• If there are UTmax and /or UT too high errors, perform GenOSC (Local Service -> Tune Up -> Expert Mode -> GenOSC). a) if GenOSC is aborted due to a problem -> continue with item 2 b) if the HV problem is not solved after GenOSC -> continue with item 3. c) if the HV problem is solved -> GenOSC tables are stored in D700 XGS. No further action necessary. 2
• If there is any doubt that the oil pressure is correct, check the oil pressure.Too low oil pressure especially in the “older”1.05bar- typ of Definition tubes is very critical compared to 1.25bar- tybe of tubes.
• Perform GenOSC with installed test plugs. See (HVC plug test / p. 30) for test plug installation. a) if the GenOSC still aborts -> check the Eventlog for CT_GSA/GRA messages and follow the instructions given in the error message. b) if the GenOSC is ok -> try GenOSC again with installed X-ray tube -> if problem recurs, change XRT (X-ray tube). 3
• Perform Gettering (Local Service -> Tune Up -> Expert Mode -> Getter). a) if the HV problem is not solved after gettering the tube -> continue with item 4 b) if the HV problem is solved -> no further action.
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SOMATOM Definition
22
XRS Step 4
Action 1. Switch off system (select System -> END) and press service switch S1 in PDC_A (Service Push-Button S1 in PDC-A / p. 11). 2. Switch off rotation enable switch S301. 3. Remove HV plugs from the HV sockets (beside the tube). 4. Remove insulators from the HV plugs. 5. Check HV plugs and the 2 insulators for signs of arcing (black dots or stripes) (HV plugs with arcing tracks / p. 26). a) If there are any signs of arcing -> continue with item 5 b) If there are no signs of arcing -> continue with item 6.
5
• If there are any signs of arcing on the plugs, HV sockets, or the insulators. a) Clean HV plugs and the 2 sockets (inside) with alcohol. b) If any signs of arcing (cracks) remain on the plug or HV sockets -> change the relevant part(s). c) If there are no signs of arcing remaining on the parts -> reinstall HV plugs using new silicon insulators (HV plug installation at HV sockets / p. 28). d) Try scanning again -> if the HV problems reoccur continue with item 6.
6
• Perform HVC tube test. Follow the dialog of the HVC tube test (tube test with HV but without load). a) If there are no XRS HV error messages found in the logbook -> continue with item 11. b) If there are XRS HV error messages found in the logbook -> continue with item 8.
7
• Perform HV plug test with installed dummy plugs ( #10 093 700) at HV sockets (HVC plug test / p. 30). Follow the dialog of the HVC plug test. (Local Service --> Test Tools --> Generator --> HVC plugs) ¹ The HV test plugs have to be installed using new insulators and have to tightened with a torque of 25 Nm . (HV plug installation at HV sockets / p. 28) a) If the test is aborted after 80 s by the UMAR (scan time exceeded), there is no HV problem on generator side --> change tube. b) If there are still XRS HV error messages found in the logbook -> continue with item 8.
SOMATOM Definition
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XRS
23 Step 8
Action 1. Switch off system (select System -> END) and press service switch S1 in PDC_A (Service Push-Button S1 in PDC-A / p. 11). 2. Switch off rotation enable switch S301. 3. Remove HV plugs from the HVT (high voltage tank). 4. Check HV plugs and the 2 silicon disks for signs of arcing (black dots or stripes) (HV plugs with arcing tracks / p. 26). a) If there are any signs of arcing -> continue with item 9 b) If there are no signs of arcing -> continue with item 10.
9
• If there are any signs of arcing on the plugs or the disks. a) Clean HV plugs and HVT sockets inside with alcohol b) If any signs of arcing (e.g. cracks) remain on the HV cable plugs or HVT sockets -> change the relevant part(s). c) If there are no signs of arcing remaining on the parts -> reinstall HV plugs into HVT using new silicon disks. d) Try scanning again -> if the HV problems reoccur continue with item 10.
10
• Perform HVC plug test scans with installed dummy plugs (#1621791) at HVT (HVC plug test / p. 30). Follow the dialog of the HVC plug test. a) If there are no XRS error messages found in the logbook (UMAR errors are acceptable) -> change both HV cables including the HV sockets. b) If there are XRS error messages found in the logbook -> change HVT.
11
• The HV problem is related to tube load. Possible reasons: Inverter problem, ground problem, HVT. a) Check Eventlog for XRS errors related to inverters -> if there are any follow the instructions given in the error message. b) Check ground connections (bad contact....) of the XRS parts.
Check/adjust the tube oil pressure
0
An incorrect oil pressure can result in various errors. If the oil pressure is too high, the tube would activate the oil pressure safety switch or the oil temperature safety switch, when the tube gets hot. The more likely case, though, is that the oil pressure is too low. Especially in the Somatom Definition (dual source), the earlier type of tubes needs to be adjusted to 1.05 bar, current tubes need a pressure of 1.25 bar.
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SOMATOM Definition
24
XRS NOTE
From 11/2009 on, new tubes need a pressure of 1.25 bar (+ altitude correction). These tubes are clearly labelled, and also the expansion unit is labelled with a red sticker. Set the pressure on “old” tubes without label to 1.05 bar, and on newer tubes to 1.25 bar according to the label.
The expansion vessel for the following measurement can be ordered from service stock. The part number for the vessel is: 10569439.
•
Cool down the system for at least 10 minutes cooling time after the last scan. During the cooling time, the system must be switched on. ¹ Be aware that some system components may be very hot, e.g., the Straton tube, XTC, etc. may reach up to 130 degrees Celsius.
• Wait until the tube and the cooling system have cooled down, then switch the system to COMP/ON status at the control box.
• • • • •
Switch off the gantry power using service push button S1 in PDC A. Remove the gantry lower front ring segment. Turn the gantry by hand until the Straton MX P tube (A or B) is in the 6 o‘clock position. Secure against unintended rotation by using the front safety bolt. Prepare the expansion vessel.
Fig. 9:
Adjusting unit for expansion membrane
• Install the adjustment handle (item 1) on the expansion vessel. - Press the button (item 2) to lock the thread rod on the membrane. - Hand-tighten the 2 screws of the adjustment thread rod (item 3).
• Open the quick coupling and disconnect the lower oil hose at the tube. Connect the oil hose from the expansion vessel to the empty quick coupling of the tube.
SOMATOM Definition
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XRS
25 NOTE
The pressure indicator at the expansion vessel shows the actual pressure in the oil circuit after the oil hose from expansion vessel has been connected.
• Check/adjust the oil pressure.
Fig. 10: Adjusting the tube pressure
• Check the pressure at the pressure indicator (item 2) attached to the expansion vessel using the expansion handle (item 1). The correct pressure for tubes without a label is 1.05 bar +/- 0.05 bar at 20°C at sea level. See following table for altitude correction of pressure. Newer tubes are clearly labelled with a sticker that requests a pressure of 1.25 bar at sea level. See following table for altitude correction of pressure.
• If the system is located at a higher altitude than sea level > add the following correction factor to the sea level pressure (see following table) ¹ For example, Potosi (Bolivia) is located at an altitude of 4000m. If an “older” 1.05bar tube needs to be adjusted there, the correct pressure would be 1.05bar + 0.39bar = 1.44bar In Mexico City (Mexico, altitude 2300m), the same tube would be adjusted to 1.3 bar, and in Hamburg (Germany, app. sea level) it would be 1.05bar. Likewise, for “newer”1.25bar tubes, the correction factor has to be considered.
Altitude [m]
Difference [bar]
0
0.00
500
0.06
1000
0.12
1500
0.17
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SOMATOM Definition
26
XRS Altitude [m]
Difference [bar]
2000
0.22
2500
0.27
3000
0.31
3500
0.35
4000
0.39
4500
0.43
5000
0.47
• If the pressure is not correct, adjust the membrane position using the adjustment handle (item 1).
• After the pressure adjustment is finished, remove the expansion vessel (remove the oil quick-snap connection to the XRT).
• Attach the second oil hose from the XTC again to the tube. • • • •
Unlock the safety bolt for gantry rotation. Rotate the gantry by hand and check for unusual noise. Close all covers opened before. Switch on circuit breakers F2, F3, F5, F6, F7, and F11 in the PDC A and F2 in the PDC B. ¹ First switch the F2, F3, F5, F6 circuit breakers to the “0” position and then to the “1” position.
• Switch the system to the SYSTEM/ON status at the control box.
HV plugs with arcing tracks
0
HV plugs and insulators with arcing tracks
Fig. 11: HV plug with signs of arcing
SOMATOM Definition
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XRS
27
Fig. 12: HV plug with signs of arcing
Fig. 13: HV insulator with signs of arcing
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SOMATOM Definition
28
XRS
HV plug installation at HV sockets
0
1. Prepare the high voltage connectors and test plugs.
Fig. 14: Silicon oil on HV plugs
Fig. 15: Silicon oil on HV plugs
• Check to ensure the connector is clean and inspect it for damage. • Apply oil (supplied with the part) to the entire plug surface (left figure, item 1). ¹ Use about half of the oil from the tube for both plugs.
• Put oil into the new silicon insulator (item 2). • Install the silicon insulator part over the plugs (left figure, item 1) ¹ Ensure there is no air left in the silicon insulator.
SOMATOM Definition
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XRS
29 2. Prepare the high voltage connectors.
Fig. 16: Silicon oil on HV plugs
Fig. 17: HV sockets
• Check that there is no air left in the silicon insulator. • Insert the O-ring onto the HV plug (item 1). • Put oil onto the silicon insulator (item 2). • Insert the high voltage plugs into the receptacles. ¹ Verify the position of the plugs (+ or -).
• Install the O-ring into the HV socket as shown (right figure, arrow). • Hand-tighten the fastening rings. 3. Tighten the HV plugs.
Fig. 18: Tightening the HV plugs
• Tighten the HV plugs using the special tightening tool (delivered with the system) with a torque of 25 Nm.
High voltage tests
0
Description of available HV tests.
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SOMATOM Definition
30
XRS HVC tube test For high tension arcing or HV breakdown, the test utility HVC tube test is available in the “Tube/Generator” test tools platform. The HVC tube test lets you apply high tension to the HV circuit without tube current. No test plugs are used in this test. No radiation is released during the test procedures. This test should always be performed before an HVC plug test is started. If this test does not indicate an error, the HVC plug test will not indicate an error either. This may lead to wrong part replacements. Prerequisites Test needs system in standby status. Performing the HVC tube test 1. Select Local Service -> Test Tools -> Generator --> HVC tube.. 2. Select Ttube A or B. 3. Click “Go” on the virtual user panel. Follow the instructions in the dialog. 4. Click the Start button at the control box. The test runs for 80 seconds. The test is terminated automatically with an error message from UMAR (scan time exceeded). If test fails perform the HVC plug test described next to select which XRS part is defective. HVC plug test For high tension arcing or HV breakdown, the primary test utility HVC plug test is available in the “Generator” test tools platform. The HVC plug test lets you apply high tension to the HV circuit without tube current. This allows the HV circuit to be systematically reduced using 2 types of test plugs to isolate a high tension fault to either the Straton MX tube, HV tank, or the HV cables. No radiation is released during this test procedure. Prerequisites
• Dummy plugs (mini type) -> part no.10 093 700 types for plug into the HV sockets. Delivered with the system.
• Dummy plugs (normal type) -> part no. 16 21 791 types for plug into the HV tank. NOTE
The HVC plug test is only allowed with test plugs installed. Tests with the installed tube can result in misdiagnosis of failures. For the installed tube, use the HCV tube test instead.
Performing the HVC plug test 1. Install the relevant test plugs in the HV sockets (front) or HVT. a) Switch off system (select System -> END).
SOMATOM Definition
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XRS
31 b) c) d) e)
Press service switch S1 in PDC_A (Service Push-Button S1 in PDC-A / p. 11). Open the gantry covers as needed. Disable gantry rotation with switch S 301. Remove HV plugs and install the test plugs. ¹ HV sockets at front: When installing test or HV plugs, new insulators must be used.
¹ HVT sockets: When installing test or HV plugs, new silicon disks must be used. f) Switch system on (S301 remains switched off). ¹ S301 has to be switched off because during Init the Rot FW searches for an index pulse. This may result in a 360 degree rotation of the gantry. In this case the removed HV cables may damage parts in the gantry. 2. Select Local Service -> Test Tools -> Generator -> HVC plugs. 3. Select HVC plug A or HVC plug B test. 4. Click “Go” on the virtual user panel. Follow the instructions in the dialog. Important work steps are listed below: 5. Click the Start button at the control box. The test runs for 80 seconds. The test is terminated automatically with error message from UMAR (scan time exceeded). -> If the test fails, follow the HV troubleshooting guide (High voltage / p. 21).
NOTE
© Siemens, 2006 For internal use only
New silicon insulators at the HV sockets (HV plug installation at HV sockets / p. 28)) as well as new silicon disks in the HVT have to be used for the HV cable and test plugs before the plugs are installed into the components (HV sockets / HVT).
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32
XRS
Filament
2.4
TSG filament
0
The filament function is tested during “Init” (e.g., COPMP/ON -> SYS/ON). After switching the gantry off/on, a self-test of the D770 (FIL power) in XGR is performed as step 1. In step 2, a filament current is sent to the filament heating in the XRT (X-ray tube), passing the filament transformer at XRT. If the self-test fails, the error message XRS_111 (XGR FIL Selftest Error) is sent to the logbook. Additionally a test utility "FIL" is available in the "Tube/Generator" test tools platform. During the "INIT" filament test, the involved D700/D770 board components in the XGR and the filament current to the XRT are tested (only in/out test). With the "FIL" test, the involved filament components and the filament regulation function are tested. So the "FIL" test is a more detailed test option. Remark: Test can be used if system is in or is not in standby status. Tab. 3
Filament test
Step 1
Action
• Switch gantry off/on using the control box (COMP/ON -> SYS/ON) to perform an XGR INIT
2
• Check in the EventLog for the error message CT_GSA/GRA_20 (XGR FIL Selftest Error). -> if the error message was sent to the logbook during INIT -> follow the troubleshooting instructions given in the error message. -> if the error message was not sent to the logbook during INIT -> continue with item 3.
3
• Perform the "FIL" test function. -> if the "FIL" test fails -> change 1. XRT and 2. XGR assembly
Filament
0
Filament test This test checks the function of the filament power board (FIL-Power) in XGR box, the cable connection to the XRT, the filament transformer at XRT, and the filament heating in the tube itself. No radiation is released during this test procedure. Performing the filament test 1. Select Local Service -> Test Tools -> Tube/Generator. 2. Select FIL 3. Click GO and follow the instructions in the dialog. The test is terminated automatically.
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33
Anode rotation (RAC)
2.5
TSG Anode Rotation (RAC)
0
An RAC frequency test function is available beginning with VA20. Use this test function to verify the RAC function. There are different anode speed (Hz) selections possible. In the troubleshooting instructions below, 160 Hz is selected because this is very stressful for the RAC function (Note: Do not use this selection in quick succession to avoid overload). An RAC extended test function is available beginning with VA20. Use this test function to check the rotating anode revolution with respect to the time (acceleration). The following statements are possible: - No revolution -> e.g., rotating anode bearing defective, bad cable/plug connection, XGR... - Revolution in the medium revolution range is too low -> e.g., rotating anode motor defective, XGR.... - Upper revolution range not reachable -> e.g., rotating anode bearing defective, XGR... Note: Test needs the system in standby status. Note: Anode rotation on a Staton MX P tube may not be started without a functioning and connected cooling circuit (e.g., for troubleshooting). Tab. 4
Anode rotation (RAC) test
Step
Action
1
• Perform AnodeRot Frequency Local Service > Test Tools > Tube/Generator > RAC and select 160 Hz. -> if the RAC test fails -> continue with item 2. -> if the RAC test is ok -> no further action.
2
• Perform AnodeRot Frequency Local Service -> Test Tools -> Tube/Generator and select the following RAC extended tests: 1. RAC anode movement test 2. RAC acceleration test 3. RAC maximum speed test
• If test 1 fails -> continue with item 3 • If test 2 fails -> continue with item 4 • If test 3 fails -> continue with item 5 3
Possible cause of error: no revolution. 1. Check cable connection W604 between XGR (X6) > XTA (X2) for broken wire or bad contact. 2. Rotating anode motor defective > change XRT. 3. XGR assembly defective > change XGR assembly.
4
Possible cause of error: revolution in the medium revolution range is too low. 1. Rotating anode bearing defective > change XRT. 2. XGR assembly defective > change XGR assembly.
5
Possible cause of error: upper revolution range not reachable. 1. Rotating anode bearing defective > change XRT
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XRS
Single pulse test
2.6
Single pulse test
0
The single pulse test allows you to identify problems from the inverter assemblies up to the HV_Tank by triggering the inverters for a single pulse. Use the single pulse test after performing the TSG “High voltage” (High voltage tests / p. 29) as a last step or if there is IMAX/UB MAX parameter information identified in an error message. Please use a memory oscilloscope to measure the output of the single pulse test. Tab. 5
Single pulse test
Step
Action
1
Perform the single pulse test (Performing the single pulse test / p. 35) with a normally connected tube. ¹ In addition to the given test result, check the UT_act value in the relevant test message in the Eventlog. If UT_act parameter is E 0x50 0x02 0x57 0x1B 0x... 0x... 0x00 > test was successful. No problem on inverter part. If UT_act parameter is E 0x50 0x00 0x4D 0x09 0x... 0x... 0x00 > test was not successful. Continue with item 2.
2
Perform single pulse test (Performing the single pulse test / p. 35) with installed test plugs (#1621791) (HVC plug test / p. 30). Follow the dialog of the HVC plug test to install the test plugs ¹ In addition to the given test result, check the UT_act value in the relevant test message in the Eventlog. If UT_act parameter is E 0x50 0x02 0x57 0x1B 0x... 0x... 0x00 > test was successful > X-ray tube problem > exchange X-ray tube. If UT_act parameter is E 0x50 0x00 0x4D 0x09 0x... 0x... 0x00 > test was not successful. Continue with item 3.
3
Compare the output diagram of the scope, the enclosed example diagrams and tolerance values shown below. The time for a single pulse has to be 9 microseconds +/- 20%. The current should have a peak value of +170A +/- 20% or -170A +/- 20% (alternating). The tube voltage (UT_act) should have a peak value above 10 kV. ¹ If the current is too high and/or the tube voltage is too low, check the MVT and HVT cabling (short circuit) ¹ If cabling is o.k. > replace parts in the following order: 1. MVT 2. HVT 3. Relevant inverter
Prerequisites
• Memory oscilloscope
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35 Performing the single pulse test 1. Move the XGS_Control assembly out of the PDC to get better access. NOTE
The power at the XGS control is 24 V and 5 V. Do not touch any parts on the XGS control. Connect the probes only as described below. To get better information, it is recommended to use a 3 channel scope as described below. If only a 2 channel scope is available, measure UT_act first and then I_load to get the necessary information.
2. Connect scope: - Channel 1 - XGS D701 > X211 UT_act (1 V = 20KV) - ANA_GND > XGS D700 > X87 - Adjust scope to 1 V/div - Channel 2 - XGS D701 > X5 I_load (1 V = 50A) - ANA_GND > XGS D700 > X87 - Adjust scope to 1 V/div - Channel 4 - XGS D700 > X104 N_Start_inv - GND > XGS D700 > X112 - Adjust scope to 5 V/div 3. Adjust scope - Time base 20 microseconds - Trigger channel 4 (neg. slope, single) 4. Select Local Service > Test Tools > Tube/Generator 5. Select Unset all in the generator application. 6. Select Single Pulse 7. Press the Start button on the virtual user panel. ¹ The test is terminated automatically. ¹ The time for a single pulse has to be 9 microseconds +/- 20%. ¹ The current should have a peak value of +170A +/- 20% or -170A +/- 20% (alternating). ¹ The tube voltage (UT_act) should have a peak value above 10 kV.
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36
XRS
Single pulse test diagrams
0
The first 2 images are good examples; the last 2 images are error examples.
Fig. 19: Single pulse test diagram
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37
Fig. 20: Single Pulse test diagram
Error examples Short-circuit at the oscillating current cable (MV cable) in the HV tank
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XRS
Fig. 21: Single pulse test diagram
Short-circuit at inverter output
Fig. 22: Single pulse test diagram
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39
Arcing
2.7
The “Arcing” test is used from the lab to simulate arcings to verify that the FW/SW reaction due to arcings is correct. This test is not service-relevant.
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XRS
XRS hints
2.8
This is a summary of troubleshooting hints obtained from experience. Tab. 6
XRS hints
Step
Action
1
The XGS_PDC control assembly A/B are identical. XGS_PDC control A assembly controls the complete switch-on process of most system parts. If this part becomes defective, the system components will not switch on. For troubleshooting and to ensure that the system components are switched on again (in case control assembly A is defective), exchange the XGS_PDC control A in PDC_A with XGS_PDC control B in PDC_B. 1. Exchange XGS_PDC control A in PDC_A with XGS_PDC control B in PDC_B in accordance with the “Replacement of parts PDC” instructions. After replacement, the guided tour for replacing parts has to be performed for the XGS_PDC_Control. 2. Always install the Dongle plug (including the 120 ohm CAN bus resistor) at XGS_PDC control B plug X3.
2
The inverter 1 and inverter 3 cable connections can be exchanged for troubleshooting (both inverters are identical). 1. Remove inverter plug X23 (inverter 1) and X43 (inverter 3) from the XGS_PDC_Control backplane. 2. Install inverter plug X23 (inverter 1) in the X43 backplane plug and X43 (inverter 3) in X23 backplane plug on the XGS_PDC_Control backplane. ¹ If the error moves with the inverter -> inverter is defective. ¹ If the error does not move with the inverter -> inverter and inverter cable ok, check for other problems such as the cable connection, ground connection, or check for other error messages produced along with the inverter error message. Follow the instructions given in this message.
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41
Switching on status display of XGS
2.9
The seven-segment display on XGS board D700 (see image below) indicates the XGS status from switching on the system up to scan execute. The status information of the display is to be used to obtain information as to the system state when a problem occurs. This information can be used for troubleshooting.
Fig. 23: D700 measuring points and LED status
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42
XRS
Fig. 24: XRS Status
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43
Measuring points
2.10
Measuring points D700, D701, D702, D703
0
D700 measuring points
Fig. 25: D700 main board Tab. 7
Oscillating current measuring points
item signal name short name
valid at
description
measuring point
1
I_load_MVT
I_L_MVT
XGS
oscillating current MVT (secondary) 1 V = 50 A.
X66
1
I_load_INV5 I_L_Inv5
XGS
oscillating current Inverter 5 / 1 X67 V = 50 A.
Tab. 8
Oscillating current and dose act. measuring points
item signal name short name
valid at
description
2
I_load_INV3 I_L_Inv3
XGS
oscillating current Inverter 3 / 1 X77 V = 50 A.
2
Dose_act
XGR
actual dose value from fast link X76 1 V = 13.107 value
Dose_act
measuring point
* other similar values with D703 Fastlink control register selectable.
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XRS Tab. 9
Voltage supply measuring points
item signal name short name
valid at
description
measuring point
3
P15V
P15V
XGS
+15 V Voltage supply
X69
3
N15V
N15V
XGS
-15 V Voltage supply
X71
3
UDC
UDC
Intermittent voltage
X73
3
VCC
VCC
XGS
+ 5 V Voltage supply
X75
3
ANA_GND
ANA_GND
XGS
analog ground
X78
3
GND
GND
XGS
ground
X80
item signal name short name
valid at
description
measuring point
4
VCC
VCC
XGS
+5 V voltage power supply
X75
4
ANA_GND
ANA_GND
XGS
analog ground
X78
measuring point
Tab. 10
Tab. 11
Ground measuring points
HW interrupt for ignition pulses main inverter
item signal name short name
valid at
description
5
XGS
Ignition switch: HW interrupt of n.a the ignition pulses from the main inverter. Normal position is off - V162 must be off. No function in XGR. Normal position is off.
item signal name short name
valid at
description
measuring point
6
P_UT act
P_UT act
XGR
positive tube voltage 1 V = 10 kV.
X81
6
N_UT act
N_UT act
XGR
negative tube voltage 1 V = 10 X83 kV.
6
UT_act
UT_act
XGR
Tube voltage 1 V = 20 kV.
X85
6
ANA_GND
ANA_GND
XGR
analog ground .
X87
Tab. 12
SOMATOM Definition
S1
S1
Tube voltage measuring points
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45 Tab. 13
IT act. measuring points
item signal name short name
valid at
description
measuring point
7
MA_meas_1 1
XGR
IT_act measurement point 1 for ampere meter.
X61
7
MA_meas_2 IT_nom
XGR
IT_act measurement point 2 for ampere meter.
X59
Measuring point
Tab. 14
Service switch
Item Signal name
short name
valid at
Description
8
S5
XGR
Switch must be on for IT_act n.a measurements using a ampere meter at measuring points X46, X48, X50, X59, X61. LED V202 is on if switch is activated. Normal position is off.
item signal name short name
valid at
description
measuring point
9
IT_act
IT_act
XGR
actual tube current
X48
9
IT_nom
IT_nom
XGR
nominal tube current
X50
9
ANA_GND
ANA_GND
XGR
analog ground
X46
item signal name short name
valid at
description
measuring point
10
VCC3.3
VCC3.3
XGS
+3.3 V I/O voltage FPGA
X20
10
VCCINT
VCCINT
XGS
+1.5 V core voltage
X44
item signal name short name
valid at
description
measuring point
11
XGS XGR
Service switch: Switch has no n.a function at this time. Nevertheless, switch must be in off position. LED V6 must be off.
Tab. 15
Tab. 16
Tab. 17
© Siemens, 2006 For internal use only
S5
IT act. measuring points
FPGA voltage measuring points
FPGA voltage measuring points
S2
S2
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XRS Tab. 18
FPGA digital out
Item signal name short name
valid at
description
measuring point
12
N_Start_FIL _INV
FIL
XGR
Start FIL inverter (low active). Can only be used in XGR.
X100
12
N_Start_RA C_INV
RAC
XGR
Start RAC inverter (low active). X102 Can only be used in XGR.
12
N_Start_HV _INV
INV
XGS
Start HV inverter (low active).
X104
12
XC
XC
XGS
XC signal (X-ray request)
X106
12
XRAY_on
XRAY
XGS
XRAY on signal (> 20 kV)
X108
12
INV_Fault
Inv_err
XGS
Summary error HV inverter Can only be used in XGS.
X110
12
GND
GND
XGS XGR
Ground
X112
Tab. 19
FPGA digital out
Item signal name short name
description
measuring point
13
Dip switches for debug and configuration of the FPGA - not for service use.
n.a
S3/S4
n.a
D701 HVC board measuring points
Fig. 26: D701 measuring points
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47 Tab. 20
D701 HVC board measuring points
Item signal name short name
valid at
description
measuring point
1
UT_act
UT_act
XGS
Actual tube voltage (from rotat- X211 ing part over fast link) 1 V = 20 kV
1
U_control
U_con
XGS
Set value for kV regulator
1
I_load_act
I_L_A
XGS
Actual oscillating current. 1 V = X215 50 A
1
USTU
USTU
XGS
Set value for kV regulator. X208 (Voltage control cycle). -5 V ... 0V
1
I_load_nom
I_L_N
XGS
Nominal oscillating current. 1 V = 50 A
1
UDC_act
UZ_act
XGS
Actual intermediate circuit volt- X210 age
1
ANA_GND
A_GND
XGS
analog ground
1
I_load
I_load
XGS
Oscillating current. 1 V = 50 A X5
1
UT_nom
UT_nom
XGS
Nominal tube voltage
X204
1
ANA_GND
A_GND
XGS
analog ground
X206
1
USTI
USTI
XGS
Set value for kV regulator (cur- X203 rent regulator circuit) 0 .... 5 V
1
Upre_con
Upre
XGS
Set value for kV regulator (pre- X201 liminary control) 0 ... 5 V
1
ANA_GND
A_GND
XGS
analog ground
X216
X207
X209
X200
D702 FIL/RAC board Tab. 21
D702 FIL measuring points
Item
signal name short name
valid at
description
measuring point
D702
IT_act
XGR
actual tube current
X18
IT_act
max. 80 mA -> 1 V = 100 mA 1 V = 80 mA D702
IF_act_1
IF_act_1
XGR
actual filament heating 1
X19
1 V = 0.273 A D702
IF_act_2
IF_act_2
XGR
actual filament heating 2
X20
1 V = 0.273 A
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48
XRS Item
signal name short name
valid at
description
measuring point
D702
IF_act_3
XGR
actual filament heating 3
X21
IF_act_3
1 V = 0.273 A D702 Tab. 22
ANA_GND
A_GND
XGR
analog ground
X17
D702 RAC measuring points
board
signal name short name
valid at
description
measuring point
D702
Test_DAC_1 DAC_1
XGS
FPGA controlled debug DAC
X10
D702
Test_DAC_2 DAC_2
XGS
FPGA controlled debug DAC
X11
D702
Res_sin
sin
XGS
Resolver Sine Signal
X12
D702
Res_cos
cos
XGS
Resolver Cosine Signal
X13
D702
RAC_P3
P3
XGS
RAC Strom Phase 3(1 V = 40 A, Offset 2.5 V)
X14
D702
RAC_P2
P2
XGS
RAC Strom Phase 3(1 V = 40 A, Offset 2.5 V)
X15
D702
RAC_P1
P1
XGS
RAC Strom Phase 3 (1 V = 40 X16 A, Offset 2.5 V)
D702
ANA_GND
ANA_GND
XGS
analog ground
X17
D732 HV acquisition HVT (high voltage tank) measuring points Tab. 23
D732 HVT measuring points
Item
signal name short name
valid at
description
measuring point
D732
ANA_GND
ANA_GND
XGR
analog ground
X12
D732
P_UT_act
P_UT_act
XGR
Tube voltage (pos.) (1 V = 10 kV)
X13
D732
N_UT_act
N_UT_act
XGR
Tube voltage (neg.) (1 V = 10 kV)
X14
SOMATOM Definition
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49
LED´s on D700, D701, D702, D703
0
D700 LED status
Fig. 27: D700 measuring points and LED status Tab. 24
D700 main board
board
signal name valid at
description
LEDs
D700
S_FIL_INV
XGR
Start FIL Inverter. Only used in XGR.
V7
D700
S_RAC_INV
XGR
Start RAC Inverter. Only used in XGR.
V8
D700
S_HV_INV
XGR/XGS
Start HV Inverter (at XGR signal V9 delayed due to transport (fastlink) delay.
D700
Cycle LED
XGR/XGS
FPGA Life Cycle LED
V10
D700
XC
XGR/XGS
XC Signal from system
V11
D700
XRAY_On
XGR/XGS
XRAY On Signal (UT_act > 20 kV)
V12
D700
INV_Err
XGS
Inverter Error
V13
D700
FPGA_Err
XGR/XGS
Error Interrupt from FPGA
V14
D700
MB 1000 mA XGR
IT_act measurement range 1000 mA
V15
D700
MB 100 mA
XGR
IT_act measurement range 100 mA (amplification *10)
V16
D700
MB 25 mA
XGR
IT_act measurement range 25 mA (amplification *40)
V17
D700
D_UT
XGR
Delta UT_act monitoring
V18
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50
XRS board
signal name valid at
description
LEDs
D700
STOP
XGR/XGS
Stop Report Loop
V20
D700
UT_MAX
XGR
UT_act max. monitoring
V21
D700
A
XGR/XGS
System A on System B off
V23
D700
rot
XGR/XGS
rotating on, stationary off
V24
D701 HVC board Tab. 25
D701 main board
board
signal name valid at
description
LEDs
D701
LED 1
n.a
not used
V205
D701
LED 2
n.a
not used
V206
D701
LED 3
n.a
not used
V207
D701
LED 4
n.a
HVC Error Interrupt
V208
D702 FIL/RAC Tab. 26
D702 main board
board
signal name valid at
description
LEDs
D702
n.a
XGR
FPGA out LED 0lim_1: Lim regulator FIL_1 active
LED_0
D702
n.a
XGR
FPGA out LED 1 20peak_1: Peak regu- LED_1 lator FIL_1 active
D702
n.a
XGR
FPGA out LED 2 20STOP_FIL/ STOP_RAC.
LED_2
D702
n.a
XGR
FPGA out LED 3 20RAC_State_0.
LED_3
D702
n.a
XGR
FPGA out LED 4 20RAC_State_1
LED_4
D702
n.a
XGR
FPGA out LED 5 20HALL_A
LED_5
D702
n.a
XGR
FPGA out LED 6 20HALL_B
LED_6
D702
n.a
XGR
FPGA out LED 7 20FIL_Error_Int / RAC_Error_Int
LED_7
SOMATOM Definition
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51 D703 XG board Tab. 27
D703 main board
Item
signal name valid at
description
LEDs
D703
LinkErr
XGS/XGR
Link Error
LED[5]
D703
LightErr
XGS/XGR
Light Error
LED[4]
D703
CfgErr
XGS/XGR
Config Error (FPGA not programmed)
LED[3]
D703
DefCfg
XGR
xray_and_not_door (XGR)
LED[2]
D703
RunCfg
XGS
door closed (XGS)
LED[1]
D703
Prg
XGR
door closed (XGR via Fastlink)
LED[0]
D703
LED 1
XGS
XGS_off (XGS indication when starting LED[6] inverter)
D703
LED 2
XGS/XGR
LifeCycle (flashes if FPGA is loaded)
LED[7]
D704 dongle board Tab. 28
D704 dongle board
board
signal name valid at
description
LEDs
D704
VCC
XGS/XGR
Power supply 5 V
V1
D704
P_15V
XGS/XGR
Power supply 15 V
V2
D790 PDC board
Fig. 28: D790 signal LEDs
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52
XRS Tab. 29
D790 PDC board LEDs
board
signal name valid at
description
LEDs
D790
P_24V_SNT
XGS
P_24V from switched power supply (only used for relays, feedback, and fans)
V1
D790
VCC_SNT
XGS
VCC (5 V) from switched power supply V2
D790
VCC3.3
XGS
FPGA IO voltage (3.3 V)
V3
D790
LED morse
XGS
FPGA Lifecycle LED (if LED flashes -> FPGA is loaded and is functioning)
V4
D790
P_15V_SNT
XGS
P_15V from switched power supply
V5
D790
VCC_INT
XGS
FPGA core voltage (1.5 V)
V6
D790
N_15V_SNT
XGS
N_15V from switched power supply
V7
D790
P_15V_SNT _AUX
XGS
P_15V from switched power supply for inverter und fans.
V8
SOMATOM Definition
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53
Fig. 29: D790 PDC board signal LEDs Tab. 30
D790 PDC board LEDs
board
signal name valid at
description
LEDs
D790
Main_Sw
XGS
PDC Main Switch Breaker Signal
V105
D790
Cooling_CB
XGS
Cooling Unit Breaker Signal
V117
D790
XGS
XGS
XGS Breaker Signal
V116
D790
PHS_CB
XGS
PHS Circuit Breaker Signal
V138
D790
Gan_Stat
XGS
Gantry Stationary Breaker Signal
V144
D790
Gan_Rot
XGS
Gantry Rotating Breaker Signal
V143
D790
UPS
XGS
UPS Breaker Signal
V157
D790
Insul_Power
XGS
Insulation Power Breaker Signal
V158
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54
XRS Tab. 31
D790 PDC board LEDs
board
signal name valid at
description
LEDs
D790
Cooling
XGS
Cooling Unit Signal
V106
D790
PHS
XGS
PHS Signal
V118
LED off -> trigger and feedback off; LED on -> trigger and feedback on; LED flashing -> trigger and feedback different D790
D790
L2_Perm_Ga XGS ntry
L2 Gantry Signal
Charg_XGR
Charging XGR Signal
XGS
V119
LED off -> trigger and feedback off; LED on -> trigger and feedback on; LED flashing -> trigger and feedback different V139
LED off -> trigger and feedback off; LED on -> trigger and feedback on; LED flashing -> trigger and feedback different D790
PWR_XGR
XGS
V145
Power XGR Signal LED off -> trigger and feedback off; LED on -> trigger and feedback on; LED flashing -> trigger and feedback different
D790
IRS
XGS
V146
IRS Signal LED off -> trigger and feedback off; LED on -> trigger and feedback on; LED flashing -> trigger and feedback different
D790
ICS_Ether
XGS
V160
ICS Signal LED off -> trigger and feedback off; LED on -> trigger and feedback on; LED flashing -> trigger and feedback different
D790
Charg_XGS
XGS
V159
Charging XGS Signal LED off -> trigger and feedback off; LED on -> trigger and feedback on; LED flashing -> trigger and feedback different
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55 Tab. 32
D790 PDC board LEDs
board
signal name valid at
description
LEDs
D790
PWR_XGS
Power XGS
V107
XGS
LED off -> trigger and feedback off; LED on -> trigger and feedback on; LED flashing -> trigger and feedback different D790
Temp_Trans
D790
XGS
Temp Transformer Signal
V120
Power_CTRL XGS
Power Control Signal
V121
D790
Diff_Sw
XGS
Diff Switch Signal
V140
D790
Volt_Prot
XGS
Voltage Protection Signal
V147
D790
Current Loop XGS
Current Loop Signal
V148
D790
Door
Door Switch Signal
V162
XGS
LED On: Door open (in PDC_B always on) D790
Fan Mode
XGS
Fan Mode
V161
LED On: low noise mode (15 V)
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56 General
3DMS
DMS 30
Safety
0
WARNING
[ hz_serdoc_F13G01U12M03 ]
Avoid accident and injury or damage to parts. Risk of accident and injury! ¹ Read and observe the safety information contained in the “General” section of this document and/or the “Product specific safety notes”. NOTE
Follow ESD guidelines when handling the DMS.
Notes
0
There are 2 Types of DMS: TACH- DMS and AMS DMS. Please check SPC for partnumbers, some spare parts are specific for one or the other type. Most noticeable are the colours of the handles of the modules: TACH modules have a grey handle, AMS modules have a pink handle.
1. Before starting troubleshooting, be sure you troubleshoot the right area. - To distinguish between the DMS’s and IRS, use the Datalink Test and check the data path first - To distinguish between DMS A and DMS B, run the DMS tests and check if the errors are related to DMS A or DMS B. - To distinguish between DMS A and DMS B, especially if image quality problems appear in Dual source modes, it is useful to have a 30 cm water phantom (Service Tool, also used for IEC Acceptance). - To distinguish between module and backplane, it is possible to cross the module cable at the backplane. If the error moves when crossing the module cables at the backplane, the problem is related to the module or module cable. - To distinguish between module and module cable, it is possible to swap the whole module cable with a neighboring one. If the error moves when swapping the whole cable, the problem is related to the module cable. NOTE
SOMATOM Definition
A second peak may appear in the displayed plot with module cables crossed or swapped. This is normal if no new calibration (e.g. a new Checkup or Setup/Calibration) has been performed prior to starting a new scan.
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57 2. If possible, use the test modes with rotation for troubleshooting especially in case of noise problems. NOTE
Use rotation modes with the collimations shown below and close all DMS covers before starting rotation.
The two most useful slice combinations for troubleshooting are: - 32 x 0.6 mm - 24 x 1.2 mm
Definitions and abbreviations
0
n.a.
Prerequisites
0
1. Check (Environmental Conditions / p. 96) (especially in case of weak rings) 2. Check for objects in the scan field e.g. contrast agent, labels,... 3. Try to reproduce an image the customer has complained about using the same parameters 4. Use (ROI/Ring / p. 69) and note the positions as a reference for the position expected to contain the defect (two positions are possible).
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58
DMS
TSG Image Quality
3.1
This chapter provides a basic overview of different types of image quality problems and a useful way for starting troubleshooting.
General
0
NOTE
Important! There is almost no cooling of the DMS electronics if the metal DMS cover is removed. If the DMS plastic cover remains installed, there is a risk of overheating. Always switch the gantry “off” completely prior to opening and working at the DMS, to prevent damaging parts.
NOTE
Most of the image quality problems are related to defective channels within a detector module. That is why troubleshooting should start with defective channel detection. This chapter is sorted for different types of image quality problems and should guide you. The DMS tests are described later in this chapter.
Possible reasons for ring and band (mostly 4, 8, or 16 channels) artifacts are:
• • • • • • • • •
Defective detector element Defective detector cable Defective backplane Insufficient calibration (e.g. contrast agent at plexiglas ring) Insufficient tune-up tables Problem with balancing (reconstruction) Insufficient environmental conditions Defective IRS Bands covering 16 channels might be caused by the incorrect Z-position of one module. Run Z-position check of module. NOTE
Problems related to a single slice appear as permanent rings in sequence modes, and as partial rings in spiral scans.
Possible reasons for streak artifacts are:
• Defective detector module • Patched channels • Alignment adjustment
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59 • Tube arcing Possible reasons for other artifacts, e.g. pattern in image, inhomogeneous areas are:
• • • • •
The tube The tube-side collimator UHR comb (not supported by VA10) The tube cooling system The DMS power supply
NOTE
If the DMS covers and parts have to be removed during troubleshooting, follow the instructions in the “Replacement of Parts” section for detailed informations how to remove and install DMS parts. Cooling is reduced when the DMS covers are removed. Never start gantry rotation with the DMS covers removed. Close the DMS covers before switching on the gantry and starting the tests.
TSG strong rings
0
In most cases we suspect that the detector module is defective. Strong bands (4, 8, or 16 channels) may also result from a defective backplane or DAS Controller.
NOTE
Offset/noise values of an entire backplane that are out of tolerance indicate a defective DAS Controller in most cases.
Tests which typically show problems in case of strong rings are:
• Offset value • Signal value • Sinogram Start troubleshooting as follows: Tab. 33
TSG
Step 1
Action
• Use (ROI/Ring / p. 69) to determine the area of the defect in the customer image
2
• Check for entries of defective channels in Reports. Refer to section defective channel detection.
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60
DMS Step 3
Action
• Compare the entries in Reports to the channels you found with ROI/Ring. a) if entries are related to the customer image -> patch out the channel manually. Refer to section defective channel detection. b) If no channel is related to the customer image, -> continue with step 4.
4
• Run (Defective channel detection / p. 70) in the Tune up platform. a) if problem is solved -> Run Quality check (Quality Constancy). b) if not o.k., e.g., too many bad channels found, -> continue with step 5.
5
• Run (Guided tour for image quality / p. 73). a) If there are errors found in one or more tests, -> continue with step 6. b) If there are no errors found, run (Sinogram / p. 80) for additional information.
6
• If only one channel is found to be defective, -> patch out the channel manually and check Reports whether the defect has remained in the system.
7
• If neighboring channels, channels in detector centers, or channels which cannot be patched out are defective -> continue with step 8.
8
• Cross the module cable on backplane with the neighboring module cable to distinguish between the module and the backplane.
• Close all DMS covers. Repeat the tests which showed errors before and check if the error moves. a) If error still in initial position -> replace the backplane. b) If error moves to neighboring slot -> module or module cable defective, continue with step 9. 9
• Swap the complete module cable with the neighboring module cable to distinguish between the module and the module cable.
• Close all DMS covers. Repeat the tests which showed errors before and check if the error moves. a) If error still in initial position -> replace the module. b) If error moves to neighboring slot -> replace the module cable. 10
• Additionally, check the power path. Especially if the errors are related to an entire backplane, -> check the power supply of the DMS. Refer to (TSG DMS Power path / p. 88)
TSG sporadic strong rings
0
Ask the customer to perform a Checkup in case of problems. Start troubleshooting as follows:
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61 Tab. 34
TSG
Step 1
Action
• Ask the customer to save the image in case of problems. a) The image is important for further evaluations with ROI /Ring.
2
• Ask the customer to perform a Checkup in case of problems. a) This particular (automatically generated) checkup table can be used for further defective channel evaluations.
3
• Use (ROI/Ring / p. 69) to determine the area of the defect in the customer image.
4
• Check for entries of sporadic channels in Reports. Refer to section defective channel detection.
5
• Compare the entries in Reports to the channels you found with ROI/Ring. a) If sporadic entries are related to the customer image -> patch out the channel manually. Refer to section defective channel detection. b) If no channel is related to the customer image, -> continue with step 6.
6
• Run (Defective channel detection / p. 70) in the Tune up platform. a) if problem is solved, -> Run Quality check (Quality Constancy). b) If not o.k., e.g. too many defective channels found, -> continue with step 7.
7
• Run (Guided tour for image quality / p. 73). a) If there are errors found in one or more tests, -> continue with step 8. b) If no errors are found, -> continue with step 9.
8
• If one channel is indicated as defective, -> patch out the channel manually.
9
• Use Reports and check for irregularities within the tests, especially in the area of the defect in the customer image.
• If irregularities are present, cross module cable on backplane with neighboring module cable.
• Close all DMS covers. Repeat the tests which showed irregularities before. a) Check reports again. If irregularities moved for 16 channels, -> replace the module including the module cable. b) If no difference is visible, swap back the cable and close all DMS covers. c) Run a Checkup and check Reports for defective channels again. 10
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• Contact HSC for further steps.
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62
DMS
TSG weak rings
0
A ring is visible in homogeneous areas such as the cerebrum, if the difference compared to the neighboring channel is about 1 ppm. In most cases we expect the stability of the element affected to be insufficient. Tests which typically show problems in case of weak rings:
• BasCal stability • Signal linearity Start troubleshooting as follows: Tab. 35
TSG
Step
Action
1
• Check (Environmental Conditions / p. 96)
2
• Ensure that DMS was powered on overnight.
3
• Check that the Tune-up was performed correctly (use Report function).
4
• Use (ROI/Ring / p. 69)to find out the area of the defect in the customer image
5
• Check for entries of sporadic channels in Reports. Refer to section defective channel detection.
6
• Compare the entries in Reports to the channels you found with ROI/Ring. a) If entries are related to the customer image, -> patch out the channel manually. Refer to section defective channel detection. b) If no channel is related to the customer image, -> continue with step 7.
7
• Run (Guided tour for image quality / p. 73) and (Popcorn noise / p. 77) test. a) Compare test outputs to channels you found in the customer image with the ROI/Ring function. b) If only one channel is defective, -> patch out the channel manually. c) If neighboring channels, channels in detector centers, or channels which cannot be patched out are defective, -> continue with step 8.
8
• Cross module cable on backplane with neighboring module cable. • Close all DMS covers. Repeat the tests which showed errors before and check if errors move. a) If error still in initial position -> swap back cable and continue with step 9. b) If error moves to neighboring slot, -> module or module cable unstable/defective, continue with step 9 and step 10 prior to replacing the module.
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63 Step 9
Action
• Check the Power path. Refer to (TSG DMS Power path / p. 88) a) If power path and DMS Power supply are o.k., -> continue with step 10.
10
• Perform Guided Table Generation in Tune up platform. Note: Table Generations for DMS A and DMS B are performed. (approx. 2 hours) a) If still not o.k. -> contact HSC for further steps.
TSG sporadic weak rings
0
In case of sporadic weak rings, perform TSG weak rings first. Additionally, start troubleshooting as follows: Tab. 36
TSG
Step 1
Action
• Ask the customer to save the image in case of problems. a) The image is important for further evaluations.
2
• Ask the customer to perform a checkup in case of problems. a) This particular checkup table can be used for further basecal evaluations.
3
• Use (ROI/Ring / p. 69) to determine the area of the defect in the customer image.
4
• Perform (BasCal Stability / p. 75). A difference between a satisfactory and unsatisfactory Basecal table will show the problem. a) If only one channel is noted, -> patch out the channel manually. b) If neighboring channels, channels in detector centers, or channels which cannot be patched out are noted -> replace the corresponding module.
TSG rings in outer slices only
0
Rings visible in the outermost slices only might occur in case of collimation problems. Start troubleshooting as follows:
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64
DMS Tab. 37
High voltage TSG
Step 1
Action
• Run (Defective channel detection / p. 70) in the Tune up platform. a) If more channels or a entire row of channels are out of tolerance, -> continue with step 2. b) If only one channel is defective, -> continue with step 5.
2
• Run (Module Z-Alignment / p. 83). a) If out of tolerance, check the mechanical positioning of the module. Refer to the replacement of parts section for instructions. b) If in tolerance, -> continue with step 3. Additionally run modes with 24 x 1.2 mm and 32 x 0.6 mm to check if the error occurs at the same physical slice position.
3
• Run Z-Adjust in the Tune up platform. a) If out of tolerance, troubleshoot the tube collimator. b) If in tolerance, repeat defective channel detection. Additionallym continue with step 4.
4
• Check slice thickness to ensure Constancy. a) Run Quality Constancy, check results for slice measurement.
5
• Run TSG strong rings
TSG Streak artifacts
0
1. Intermittent streaks tangential to a circle might be caused by a defective module Start troubleshooting as follows: Tab. 38
TSG
Step 1
Action
• Run (Defective channel detection / p. 70) in the Tune up platform. a) If no channel is found to be defective, -> continue with step 2. b) If defective channels are detected, -> continue with step 3.
2
• Run (Popcorn noise / p. 77) test to isolate the defective channel.
3
• Run TSG strong rings
2. Streaks tangential to a circle might be caused by too many patched channels. Start troubleshooting as follows:
SOMATOM Definition
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65 Tab. 39
TSG
Step
Action
1
• Run (Defective channel detection / p. 70) in the Tune up platform.
2
• Check if there are adjacent patched channels and continue with step 3.
3
• Check Reports for defective channel detection. a) If “-> change” is written in Reports, replace the corresponding module. b) If “-> change” is not written in Reports, -> continue with step 4.
• Run TSG strong rings
4
3. Fine streak artifacts not correlated tangentially to any circle might be caused by incorrect alignment. Start troubleshooting as follows: Tab. 40
TSG
Step
Action
• Run (MTF test / p. 78) and check for tolerances.
1
a) If in tolerance, -> continue with step 2 and step 4. b) If slightly out of tolerance, -> continue with step 2. c) If results not plausible, go directly to step 3. d) If only UHR modes (not supported by VA10) are out of tolerance, -> continue with step 4.
• Run (Focus Alignment Check / p. 82) in the Tune up platform.
2
a) Continue with Focus Alignment in the Tune up platform. Note: Continue with Focus Alignment as well if the Focus Alignment check is in tolerance. If Focus Alignment fails, -> continue with step 3. 3
• Troubleshoot tube collimator (PSD) and Focus deflection.
4
• Run comb ali (UHR is not supported by VA10).
5
•
Run TSG weak rings.
4. streak artifacts not correlated to any object might also be caused by tube arcing. Start troubleshooting as follows:
• Tube arcing ¹ Check the tube history for this paticular scan to see if tube arcing was detected. Getter tube
TSG Dual Source problems
0
Notes:
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66
DMS • Image quality problems in dual source modes appear most often as a band in the area where the scan field of the DMS B is extended by the outer channels of DMS A. In dual source modes the inner 26 cm of the scan field are measured by both DMS’s, the outer area of the scan field (outside 26 cm) is measured by DMS A only. Measure the HU in the area of the band. Especially in case of a high absorption (obese patients), a high difference in HU can be measured in the inner and outer area of the scan field. NOTE
For troubleshooting dual source problems, it is very helpful to have a 30 cm water phantom as used for the IEC Acceptance.
• Start troubleshooting as follows: Tab. 41
TSG
Step 1
Action
• Check if the problem is caused by one of the DMS’s, or if the problem appears only in dual source modes. a) Run single source modes (B-modes) in the Rot mode platform and use a 20 cm water phantom. If the images are free of artifacts, -> DMS B is ok. If the images show artifacts, troubleshoot the DMS B first. Refer to the corresponding TSG in this document. b) Run single source modes (A-modes) in the Rot mode platform and use a 30 cm water phantom. If the images are free of artifacts, -> DMS A is ok. If the images show artifacts, troubleshoot the DMS A first. Refer to the corresponding TSG in this document. c) Run dual source modes (A/B-modes) in the Rot mode platform and use a 30 cm water phantom. If artifacts appear in the area where DMS A adds DMS B data (at 26 cm scan field), -> the problem is related to dual source modes only. Continue with step 2.
2
• Check if the problem is caused by incorrect scatter radiation correction. a) Run a dual source mode (A/B-modes) in the Rot mode platform with Cross Scat selected (use a 30 cm water phantom). b) Run a dual source mode (A/B-modes) in the Rot mode platform with Cross Scat deselected (use a 30 cm water phantom). With Cross Scat selected, the critical area (at approx. 26 cm) must look more homogeneous. If no difference is visible, the correction is wrong or not working. -> Continue with step 3.
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67 Step 3
Action
• Run quality constancy and check homogeneity. a) If homogeneity is out of tolerance -> Run Water Scaling for the corresponding DMS (A or B).
4
• Perform Guided Table Generations in the Tune up platform. Call HSC for further advice. Note: Table Generations for DMS A and DMS B are performed. (approx. 2 hours) a) If still not o.k. -> contact HSC for further steps.
TSG Spatial Resolution (bad MTF results)
0
Start troubleshooting as follows: Tab. 42
TSG
Step 1
Action
• Run (MTF test / p. 78) and check for tolerances. a) If slightly out of tolerance, -> continue with step 2. b) If results not plausible, continue directly with step 3. c) If only UHR modes (not supported by VA10) are out of tolerance, -> continue with step 4.
2
• Run Foc. Align. check in the Tune up Platform. a) Continue with Focus Alignment in the Tune up Platform. Note: Repeat Focus Alignment as well if the Focus Alignment check is in tolerance. If focus alignment fails, -> continue with step 3.
3
• Troubleshoot the tube including the tube collimator and the regulation circuit.
4
• Run Comb Ali in Tune up platform (UHR not supported by VA10).
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68
DMS
TSG other artifacts
0
Pattern across the entire image
• Perform tests or test images with and without X-ray to find out if the problem is related to radiation. Additionally, run (Guided tour for image quality / p. 73). If the problem is related to radiation: ¹ - Check (replace) tube - Check (replace) tube collimator If the problem is not related to radiation: ¹ - Check the DMS power supply - Check the modules at slots 1 and 42 in DMS A (air slice normalization) Inhomogeneous areas To identify the source of the problem, evaluate the BaseCal values (contact CS HSC). The reasons for inhomogeneous areas in the image (with radiation) are mainly:
• Defective BaseCal tables (visible mainly in the cerebrum sequence): If calibration was performed with an absorber (contrast media) in the scan field: The artifact is stable (in the same image area) in all images. ¹ Check the Reports for entries. (Options > Service > Local Service > Reports ) ¹ Clean the plexiglas ring and check for other absorbers in the scan field. Repeat calibration. Inhomogeneous slices If the mean value (of the same image area) differs from slice to slice : ¹ Check the modules of slots 1 and 42 in DMS A (air slice normalization)
NOTE
The task of air slice normalization is to equalize all slices. Some of the channels of the modules in the first and last slot (1 and 42 in DMS A) are used to calculate a mean value for each slice. All slices are now compared and equalized.
Poor image quality due to wrong scan parameter or usage There are also non-technical reasons for certain types of image quality problems.
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69 • Windmill artifact If you browse through a stack of images, the image contains an artifact that moves like a windmill. It is especially visible at the edges of bones. Windmill artifacts occur due to undersampling or interpolation. ¹ Compare the pitch used with the Siemens default values. ¹ Check if the reconstructed slice width is 1.25 times the collimated slice width. ¹ Involve Applications in troubleshooting
• Artifacts due to patient positioning or use of positioning aids. (mainly streaks) Head: ¹ Check to see if the correct head holder was being used. Body: ¹ When using the CT-slicker, bend the edges down and glue them to the table
Tests for Image Quality
0
This chapter provides a list of all software tools available for handling DMS problems. ROI/Ring Scope
• The ROI function (region of interest) is used to calculate the mean value and the standard deviation of a user-defined area.
• The Ring function shows the correlation of a position in an image to 2 possible channels in the DMS that have been involved in creating data at that position. How to find
•
Options > Service > Local Service > Test Tools > ROI/Ring
How to use 1. Select the desired order for sorting the images in the list box by activating the corresponding radio button. (You may have to wait.) 2. Mark the image of your choice in the list box. Select the image by double clicking or use the Load Loid Button. ¹ The image will be displayed The Button Switch to File Chooser enables loading of images from different locations. 3. Select the radio button Ring 4. Use the left mouse button to move the ring to the desired position. Use the center mouse button for windowing. ¹ Read out the 2 possible channels (channel1, channel2) causing the problem. ¹ Use this information as the basis for additional troubleshooting.
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70
DMS Defective channel detection The software automatically detects bad channels. The center of DMS A and the first and last slot (used for air slice normalization) have to be without defective channels. In all other slots a certain amount of defects is allowed. 1. Check for allowed defects under Reports NOTE
If you find “=>change” within the Reports, the defect cannot remain in the system and the broken part has to be replaced. Test DMS to find out if the module is really broken.
Using the Report function: Options > Service > Local Service > Reports > Tune Up > Table Generations - Def Chan. Cust. ¹ Shows status of last defective channel detection during checkup. - Def. Channels ¹ Shows status of last defective channel detection during tune-up. - Options > Service > Local Service > Reports > Def. Chann. History. -
-
¹ A history of all channels that have been patched or unpatched is shown. check affected modules. =>change : indicates that the corresponding module has to be exchanged. If a sporadic defect within the reports corresponds to the customer image, patch out the channel manually. Refer to “editing the correction tables”. Check the affected modules again after patching to determine whether the module is allowed to remain in the system. (=>change : indicates that the channel/channels cannot be patched out and the corresponding module has to be exchanged.) If no defect corresponds to the customer image, run automatic defective channel detection in the Tune-up Platform. Refer to “Defective channel detection in tune up platform” (item 3)
2. Performing Defective Channel Detection in the Tune-up Platform -
Select Local Service > TuneUp > Expert Mode > Defective Channels. Remove all absorbers. Select (DMS A/DMS B or both) under Select Scan Mode. Click Auto.
¹ To repeat automatic detection in case of unstable / implausible results, repeat the procedure with the auto button. - You will be asked to accept the current calibration. - Click Save. ¹ The IRS tables are transfered to the IRS. ¹ If you click Cancel, no modifications to the tune-up and IRS tables will be stored. - Check Reports to determine whether a defect has been found and sucessfully pached out. - The program is not sensitive enough to detect all kinds of defects. If a defect is not found during the procedure, the DMS tests are necessary.
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71 NOTE
If a defect was found and sucessfully patched out during the procedure, the images must be free of artifacts now.
3. Editing the correction tables - Select Local Service > TuneUp > Expert Mode > Defective Channels. - Click the button for the corresponding DMS. (A or B) - Click the button for the desired detector slot (1- 42 for DMS A) or (1 to 22 for DMS B). Hint: A segment containing unsatisfactory elements is marked in red. - After a while, the user interface will show the corresponding channel / slice matrix. ¹ Now select the desired channel and slice. Select the element with the left mouse and click it. The color will change from green to red.
-
© Siemens, 2006 For internal use only
¹ Left-click to remove an unsatisfactory channel entry. The color will change from red to green. Click save after modifications. Continue, if necessary, with Correction Tables > TuneUp > 24x1200. Click save after modifications. For additional information regarding defective channel detection, refer to (Hints for defective channel detection / p. 97).
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72
DMS Common for all tests which provide a plot function
Fig. 30: Example of Relative Signal Value DMS A in error condition
• Common for all tests which provide a plot function for the results: - The button Show Plot shows the graphical output of the table. Select all slices via Show All, none via Hide All, or a single slice via the list box. Zoom in (or out via Survey) using the left mouse button. Mark the area of interest while holding down the left button. Then press Zoom In . Position the cursor at the desired location and wait for the display of: - channel - slice - value at that position The button Statistic displays the following for all slices: Minimum, Maximum, Mean, and StdDev. The min. and max. values are shown only if the checkbox Y-Auto Scale is not marked.
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73 - The button Extract to file is used to store the result of the test to c:\Somaris\ service\extract\DmsTestExtract.txt Hint: If you want to store more than one file, you have to manually change the file name. - The display of the tolerances in the plot may be switched on or off using the checkbox for Tolerance
• Tolerances are available for all test results. NOTE
The Tolerance limits are indicated by red lines in the plot.
As a result, test result pages display the following at the top of each page: OK for tests passed or Not OK for tests failed.
• In case of values out of tolerance, the slice and channel are output. Click the channel number and read out: Channel xxx and Slot xx. Guided tour for image quality Scope
• The guided tour is an automatic sequence containing most of the DMS Tests available at the system. How to find
• Options > Service > Local Service > Test Tools > Image Quality How to use 1. Press Go NOTE
Offset value starts automatically after pressing the Go Button.
2. Wait for Press START key to appear and then press the Start button. 3. Wait for the results. - Check if the test results match with the artifact which you localized before with Roi/Ring. Return to TSG Image quality. Offset value Scope
• This test is used to check the mean values and noise without X-ray. How to find (if not using the guided tour)
• Options > Service > Local Service > Test Tools > DMS > Offset Value
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DMS How to use 1. Select the desired mode (DMS A/DMS B or both). 2. Press Go 3. Wait for the result ¹ Replace modules that exceed the threshhold 4. Description of the result page The results of the test are shown in two tables: - Offset value - Offset noise Both tables show Slice, Minimum, Maximum and Test Result. Use the Show Plot button to display the plots. Signal value Scope
• This test is used to check the mean values and noise with X-ray. Different collimations are used. How to find (if not using the guided tour)
• Options > Service > Local Service > Test Tools > DMS > Signal Value How to use 1. Select DMS A/DMS B or both in the platform. 2. Wait for Press START key to appear and then press the Start button. 3. Description of the result page The results of the test are shown in three tables: - first table: Relative Signal Value The result shows the averaged signal of the channels in relation to the neighborhood. This table shows Slice, Minimum, Maximum, and Test Result. - second table: Relative Standard Deviation This table shows Slice, Minimum, Maximum, and Test Result. In addition, the monitor value is shown. - third table: Absolute Signal Value This table shows Slice, Minimum, Maximum, and Test Result. In addition, the monitor value is shown. Common for all tables is:
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75 - The button Show Plot graphically displays the table. It’s possible to select all slices via Show All, none via Hide All, or a single slice via a checkbox. It’s also possible to Zoom In (or out via Survey) by using the left mouse button. Mark the area of interest while holding down the left button The button Statistic displays the following for all slices: Minimum, Maximum, Mean, and StdDev. The check box Y-AutoScale allows automatic scaling of the Y-axis. - For values out of tolerance, slice and channel are output. Click the channel number and read out: Channel xxx and Slot xx. - The button Extract to file is used to store the result of the test to disk. BasCal Stability Scope
• The main function of the BaseCal stability test is to subtract the last two BaseCals of one given mode in order to find unstable channels. The structure of the BaseCal names is: basecal_slice_ tube voltage_ scantime_ focus size_algorithmn_organ_focus type. They are stored in c:\Somaris\service\datastore\icstables How to find (if not using the guided tour)
• Options > Service > Local Service > Test Tools > Sys. Test > BasCal Stability How to use 1. Select DMS A/DMS B or both in the platform 2. Use the BaseCal corresponding to the mode the customer is complaining about. 3. Press Go ¹ The result page is shown. ¹ Before exchanging modules, compare the result with the results of ROI/Ring to verify whether the customer’s image problem has been located. 4. Activate Show Plot ¹ Evaluate the plot In addition to the standard functions, you can define the Segments which should be shown. Hint: A BaseCal is referred to as a 360 degree rotation and is divided into 10 angular segments.
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DMS Signal linearity Scope
• This test performs two scans with different tube currents (100mA and 300 mA). Subtracting the mean values of these scans shows the deviation caused by the signal non-linearity. In addition, you may use phantoms in the scan field to check the low signal linearity. How to find (if not using the guided tour)
• Options > Service > Local Service > Test Tools > DMS > Signal Lin. How to use 1. Wait for the Press START key to appear and press the Start button ¹ The test result page is displayed. ¹ In case channels are out of tolerance, change the corresponding module. 2. Press Show Plot ¹ The plot is displayed Assignment test Scope
• The assignment test is an internal addressing test of the DAS Controller. How to find (if not using the guided tour)
• Options > Service > Local Service > Test Tools > DMS > Assignment How to use 1. Select DMS A/DMS B or both in the platform 2. Wait for the Press START key to appear and then press the Start button ¹ Wait for the result page 3. Activate Show Plot ¹ A continuous staircase from upper left to lower right should be visible for all slices. Hint: In addition to the standard function, you can define: - Segments (frames) and - FFS 1, 2 or all 4. Interpretation of the result The possibly defective part may be: - defective detector module - defective backplane - defective DAS Controller
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77 X-ray Path Scope
• This test involves finding any “contamination” in the X-ray path. A scan is performed and the 2 focal spots are subtracted. Depending on the position of an object in the X-ray path, the plot looks different. - If the object is near the detector, the contamination covers only a few channels. (Contamination through contrast agent) A peak at one channel is most likely a damaged detector collimator - If the object is near the tube (or tube collimator), the plot will cover a lot of channels and the deviation in the plot looks “weak”. How to find (if not using the guided tour)
• Options > Service > Local Service > Test Tools > Sys. Test > X-ray Path How to use 1. Select DMS A/DMS B or both in the platform 2. Wait for the Press START key to appear and then press the Start button. ¹ The test result page is displayed. ¹ If channels are out of tolerance, contact CS HSC for further advice. 3. Press Show Plot to see the plot ¹ Capture the plot and supply it to CS HSC for additional evaluation. Popcorn noise Scope
• The principle of the popcorn noise test (spike test) is to monitor a number of offset scans to find unstable channels. As a result, ppm thresholds are defined for the values. If these thresholds are exceeded several times (e.g. max. number of spikes), the test identifies the corresponding channels.
• It is difficult to find suitable tolerances for this test. In general, this test should be used to find sporadic problems. (For instance, to find the worst channel.) How to find
• Options > Service > Local Service > Test Tools > DMS > Popcorn Noise How to use 1. Select System A or System B in the platform. 2. Select "max. number of spikes". 3. Select "lower threshold" (use default values first).
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DMS 4. Select "upper threshold" (use default values first). 5. Select "number of measurements". 6. Select "test with or without rotation". Start troubleshooting with rotation 7. Press Go ¹ Check results to find channels that lie outside the threshold. ¹ Lower the value for the upper threshold from 100 to 50, 30, and 20 to get the worst channel output. MTF test Scope
• The MTF (Modulation Transfer Function) shows the spatial resolution at high contrast. For this purpose, a 0.22 mm tungsten wire phantom is used. How to find
• Options > Service > Local Service > Test Tools > Sys. Tests > MTF-Test How to use
• Follow the program output. If a value is out of tolerance, it is indicated by a “>” sign. Offset image Scope
• The offset image is calculated from an offset-corrected raw image added to a synthetic disk. The raw image is acquired without radiation. As a result, the artifacts visible in the offset images are not related to the X-ray or the UFC of the detector. Instead they are primarily related to the electronics of the integrator section.
NOTE
The offset images may have ring artefacts. Therefore the offset images cannot be used for evaluation or decision to replace DMS parts.
How to find
• Options > Service > Local Service > Test Tools > DMS > Offset Image
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79 How to use 1. Select “Set System A” or “Set System B” 2. Select the radio button for rotation “on” or “off”. Start testing with rotation. 3. Select a scan time. Start with the scan time the customer is complaining about. 4. Press Go and wait for the result ¹ The offset images are calculated. Images have to be without rings, bands, or streaks. Check images with window 550 and center 0. In case of problems: ¹ Continue with the Offset value. 5. Select radio button “images are correct" (or not correct). 6. Interpretation of the results: The images must show a homogeneous noise structure and must be without: - Rings or partial rings - Streaks - Any other visible structures.
NOTE
The offset images will be stored under Service patient. The offset measurement will be aborted in case of an active patient.
Spectral linearity Scope
• This test performs two scans with different tube voltages (120 kV and 140 kV). Subtracting the mean values of these scans shows the deviation caused by the spectral non-linearity. The result of this test shoud be used only in addition to other tests to confirm a channel as satisfactory or unsatisfactory.
• This test is normally used in the factory only. How to find
• Options > Service > Local Service > Test Tools > DMS > Spectral Lin.
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DMS How to use 1. Select DMS A/DMS B or both in the platform 2. Wait for the Press START key to appear and then press the Start button. ¹ The test result page is displayed. ¹ If there are channels out of tolerance, call CS HSC. 3. Press Show Plot ¹ The plot is displayed. Sinogram Scope
• The output of the sinogram is an image showing all channels at the X-axis as well as all frames (projections) at the Y-axis.
• Raw data sets of air scans and of scans made with a homogeneous absorber can be evaluated. NOTE
If rotstatic.raw should be evaluated, ensure that “Transfer Raw Data” was selected in the Rot/Static Platform. Otherwise, the rotstatic.raw file is not available in the Sinogram platform.
• The sinogram is a useful tool for locating weak rings How to find
• Options > Service > Local Service > Test Tools > Sinogram How to use 1. Mark a file in the list box Raw Data Files. 2. Mark or unmark the checkboxes for Convolve with Kernel and Median filtering . Start with the marked checkbox for Convolve with Kernel.
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81 3. Press Go ¹ The plot is displayed and you can select the slice via the select box. ¹ Using the left mouse, mark a position to display the corresponding frame and channel. ¹ The mean value and standard deviation of a marked area are shown, if you use the left mouse button to mark the desired area.
Fig. 31: Example of sinogram result for DMS A
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DMS 4. Interpretation of results: -
A vertical line shows up in all frames if a channel is defective. A vertical dotted line shows up if a channel is defective but not throughout all frames. A horizontal line shows up if a frame is defective (projection). A dot shows up if a channel is defective in one frame. A sine wave shows up if a stationary absorber is located in the scan field. (Absorber is not moving with DMS)
Tube Collim. Check Scope
• This test checks the correct opening width and Z-position of the tube collimators. IRS tables are used, which have been generated during air calibration. No scans are performed during this check. How to find
• Options > Service > Local Service > Tuneup > Expert Mode > Tube Collim. Check How to use 1. Press Go 2. Wait until the message “Tube collimator Check completed” appears. ¹ If the result is out of tolerance → Perform a tune-up. Follow the guided tour for Tube Collimator → Troubleshoot the tube collimator and the regulation circuit (UMAR). Focus Alignment Check Scope
• This test uses the ball phantom to check if the electromagnetic focus deflection (flying focal spot) in PHI and in Z-position is working properly. How to find
• Options > Service > Local Service > Tuneup > Expert Mode > Foc.Align.check How to use 1. Select System A / System B or both in the platform. 2. Press Go 3. Select and insert phantom. 4. Press Go 5. Wait for the Press START key to appear and then press the Start button.
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83 6. Wait for the results. ¹ If the result is out of tolerance → Repeat the test to find out if the result is failing constantly. → Perform Z-Adjust and Focus Alignment and repeat the test. → Run guided tour for X-Ray Tube Tune-up. → Exchange X-Ray Tube Note: Contact CS HSC before ordering the tube. ¹ If the result is not plausible → Check if Focus Alignment was performed after the Tube replacement. → Troubleshoot the tube collimator and focus deflection. Module Z-Alignment Scope
• It is possible to position the modules at the incorrect position during replacement. An automatic module position check is implemented in the guided tours. Follow the software instruction in this case. The Z alignment of the module is tested by evaluating 2 air scans with different tube collimator positions. How to find
• Options>Service>Local Service>Test Tools>DMS>Module Z-Align How to use 1. Select DMS A/DMS B or both in the platform 2. Press Go 3. Wait for Press START key to appear and then press the Start button. ¹ The test result page is displayed.
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DMS 4. Press Show Plot ¹ The following plot shows well aligned modules.
Fig. 32: Module Z-alignment
5. Check if there is a drop of 16 channels (use the Zoom function), especially at the position where you performed repairs. If yes, loosen the module exchanged previously and press it toward the rotating plane while you are fixing the situation. Repeat the test. Analyze Scope
• Analyze is a versatile tool, used to evaluate raw data as well as header data. The following functions are useful for field services: - Integration time - Dose monitor - DMS Temperatures
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85 - Raw Data Frequency Analysis How to find
• Options > Service > Local Service > Test Tools > Analyze How to use
• Using the macros under Special 1. Select the radio button ICS-RawData 2. Mark the desired raw data set in the list box 3. Press Go ¹ View is automatically selected and the plot appears. 4. Select Special 5. Mark the desired checkbox - ReadingNo - TubeAngle - MaximumValue - ErrorInfo - CRC Error - IntegrationTime - Dose monitor - DMS-Temperature 1 - DMS-Temperature 2 - DMS-Temperature 3 - DMS-Temperature 4 and press Go ¹ The corresponding curve is displayed.
• Using the raw data frequency analysis under Analyze - Load an A or B static mode with 2 x 1.0 mm. - Perform 2 scans of that mode and use the second one -
Open an additional window. Start Options > Service > Local Service >TestTools > Analyze Select ICS-Rawdata mark rotstatic.raw and press Go. Select Tools Select Raw Data - Frequency Analysis and press Go Select the channels Start with 305 to 368 at DMS A. - Do not select the checkbox for fusing the slices. - Do not select Separate FFS - Select all slices
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DMS As shown in the example, press Go and zoom the result, if necessary. The X-axis shows the frequency, and the Y-axis shows the amplitude.
Fig. 33: Example of raw data frequency analysis
¹ The amplitude at the first peak (here 120 Hz) shows the quality of anode rotation (wobbling anode). A peak does not necessarilly mean that the tube has to be replaced. Check also for tube arcing and other errors related to the tube. ¹ The amplitude at the first harmonic shows the quality of the emitter (tube). NOTE
In addition to this test, the tube has to be checked before making the decision to replace it.
¹ Send the plot to CS HSC for additional evaluation.
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87 Band assessment tool Scope
• This test performs automatic test scans and runs an algorithm to find ring structures in water phantom images. The disadvantage is that only the range of the phantom is checked (20 or 30 cm). In the factory a special phantom consisting of 3 parts is used: - 20 cm body - 20 cm head - 30 cm body The phantom is not delivered with the system. How to find
• Options > Service > Local Service > Test Tools > Sys. Tests> Band Assessment How to use 1. Position the phantom so that it lines up with the engraved mark. The table position is checked. 2. Select the desired modes. Possible choices: Select all, Deselect all, and Select box 3. Press Go ¹ If results are out of tolerance, go to TSG Image Quality.
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DMS
TSG DMS Components
3.2
TSG DMS Power path
0
NOTE
Troubleshoot the DMS B power supply in the same way. The only difference is that the DMS B consists out of one backplane, and therefore only one power cable is connected to the power supply.
The 2 power supplies for the 2 DMS are located behind the metal DMS front covers. To check the power supplies, check the LEDs at the front of the corresponding DMS. In addition, the supply voltages can be checked as well on the left and right backplane of DMS A and on the backplane of DMS B. Tab. 43
TSG DMS power path
Step 1
Action
• Check Power LEDs on the DMS power supply. All LEDs must be “on”. a) If one or more LEDs are “off”-> check input power at DMS power supply. Measure at X1 on the DMS power supply. b) If all LEDs are “on” -> continue with item 2.
2
• Check LED’s on DMS Backplanes, all must be “on” and green. a) If voltages are missing at a backplane, the backplane LEDs change from green to red. In this case check the cables between DMS power supply and the backplanes. If the cables are o.k. -> DMS power supply or backplane defective.
NOTE
The power cable of DMS B can be used in DMS A for troubleshooting.
Important: The tolerances given below are valid only for the test points at the backplanes. Test point
Ground
TACH power supply 10023351
AMS power supply 10023352
+24V
24VRET
24 V / 6 A controller
24V
pos_V_D
DGND
3.4V / 11A module digital
3.4V
pos_V_A
AGND
4.6V / 21A module analog
3.4V
neg_V_A
AGND
-3.65V / 18A module analog
-3.1V
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89 • To check the voltages at the DMS backplane, evaluate the following test points and LEDs:
Fig. 34: LEDs of DMS backplane
TSG short circuit in power supply NOTE
Troubleshoot the DMS B power supply in the same way. The only difference is that the DMS B consists out of one backplane, and therefore only one power cable is connected to the power supply.
To track down a short circuit in the power supplies, cables, backplanes, DAS Controller, or modules, perform the following: Before following this advice, be sure the mains input for the DMS power supply is ok. Tab. 44
TSG short circuit in DMS power path
Step 1
Action
• Check Power LEDs on DMS power supply. a) If the LEDs are “off” -> continue with step 2.
2
• Disconnect X30 at left DMS backplane and check DMS power suppy LEDs. a) If one or more LEDs are “off” -> check input voltage b) If all LEDs are “on” -> problem is related to left backplane, DAS Controller, all modules connected to the backplane. ¹ Disconnect the parts mentioned to isolate the fault
3
• Disconnect X31 at right DMS backplane and check DMS power suppy LEDs. a) If one or more LEDs are “off” -> check input voltage. b) If all LEDs are “on” -> problem is related to right backplane, DAS Controller, all modules connected to the backplane. ¹ Disconnect the parts mentioned to isolate the fault
4
• If X30 and X31 are disconnected, and the LEDs on the power supply are still “off”, disconnect the 2 power cables (X2 and X3) at the power supply to determine whether a short circuit is present in the cables.
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DMS
TSG UHR mechanics
0
If there are problems with the UHR mechanics, follow the advice provided in the error message. To understand the function of the UHR control (implemented in the UMAR), the current applied to the UHR motor is shown in the next figure. UHR phi-z comb: Current measurement is not possible. Follow the mechanical checks.
Fig. 35: Current of UHR motor
To identify problems of the UHR control, you may perform the following tests: Mechanics
• Check whether the mechanics are operating smoothly by moving the UHR in and out by hand. (remove the UHR motor to be able to move the UHR without applying too much force) ¹ If the mechanics are not moving smoothly: → Check for parts blocking the UHR. Service switches
• Using the UHR service mode with the system in standby mode: -
Press “Stop” on the gantry or control box Switch on the service switch on the UMAR Press S1 (in) and S2 (out) on the UMAR to check UHR comb movement Press “Test” on the UMAR to perform a self-test Switch off the service switch on the UMAR
• Using the UHR service mode with the system not in standby mode: -
Switch the gantry to “Comp on” Switch on the service switch on the UMAR Switch the gantry to “Sys on” If the ICS aborts with the message “Can’t continue...”, press the “Test” button on the UMAR prior to using S1 (in) or S2 (out) - Switch off the service switch on the UMAR
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91 Limit switches
• If the problem is related to the limit switches: - Check their functionality using the service switch on the UMAR and move the UHR in and out by pressing S1 (UHR in) or S2 (UHR out). (Described above) Ensure that MOVE LED on the UMAR is activated at both mechanical end stops. ¹ If the LED is not activated at the end stop on one side: Position the UHR in the middle, so that no limit switch is activated. Use a piece of metal, e.g., a screwdriver, to check whether the limit switches are working properly. ¹ If the LED in the limit switch is not activating: → Check the power supply for the switch on the UHR control → Replace the corresponding limit switch - For checking the adjustment of limit switches, refer to the document Replacement of Parts: Gantry. UHR motor
• If the problem is related to the UHR motor: - Check their functionality using the service switch on the UMAR and move the UHR in and out by pressing S1 (UHR in) or S2 (UHR out). (Described above) Observe whether the UHR is moving. ¹ If the UHR comb is not moving: Measure the voltage for the UHR motor at UHR control D586 J1 (power) while activated via the service switches. → If the motor is not moving while voltage is present, replace the motor. → If there is no voltage, replace D586. Adjustment
• To ensure the UHR is adjusted correctly in the phi-direction, perform an MTF measurement. If the results are in tolerance, the adjustment is OK. If the results are out of tolerance, perform COMB ALI in the Tune-up platform. If the comb is fully maladjusted, the core position can be identified by evaluating a mean value plot of an UHR mode. Core position check of UHR comb If the UHR comb was largely maladjusted or the initial position was lost, you can try and find the core position by using analyze.
• Start Analyze Options > Service > Local Service > Test Tools > Analyze
• Select the radio button ICS-Tables • Mark an UHR mode BaseCal and press Go.
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DMS • The plot of the BaseCal appears.
Fig. 36: Example of an UHR BaseCal plot
• Zoom both edges to see the channel where the UHR comb starts and ends.
Fig. 37: Zoom of lower channel side
Fig. 38: Zoom of higher channel side
¹ Compare your results with this example showing a well-adjusted UHR. The first channel with a higher value is channel 139 The last channel with a higher value is channel 534 Disabling the UHR comb
• If a defective UHR comb prevents the system from reaching standby, the comb can be disabled momentarily.
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93 How to disable the UHR comb: 1. Move the comb manually to the mechanical end out of the X-ray path 2. Disconnect the connector of cable W401
Fig. 39: UHR connection Pos. 1
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Cable W401
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DMS 3. After the next INIT, save the machine configuration by selecting “none” for UHR (refer to the example below)
Fig. 40: Factory-specific CT configuration
4. Save a copy of the original license.dat file
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95 5. Disable the UHR licenses by putting a “#” in front of the related licenses. (Refer to the example below)
Fig. 41: License.dat Pos. 1
License deactivation
NOTE
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Do not forget to restore the original configuration once the UHR comb is working again.
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DMS
Additional Tests & Hints
3.3
Storage of Test Results
0
• Test results are stored in two different ways: - As HTML files Path:c:\Somaris\service\html\report\htmlreport - As TXT files Path:C:\Somaris\service\extract - Additionally, it’s sometimes helpful to use a screenshot to report the result plots: - Activate the window you intend to capture - Use Ctr / PrtSc to capture the window - Start > Programs > Acessories > Paint - Use Edit > paste - File > save as and use file type gif to reduce the size Normally, HTML files are used to store test results. However, the plots of the DMS tests are usually stored in a text file (via Extract to File button). Please note: the file name has to be changed manually. Otherwise, the file will be overwritten each time the softkey is used. The file may be displayed using Excel (e.g. after manual remote transfer).
Environmental Conditions
0
Environmental conditions are a possible reason in case of weak ring artifacts. Check the Somaris log for errors and warnings . Gantry Inside the gantry, the temperature is regulated. To read out the actual values for temperature, use the control platform The output of the table may be selected in decimal or hexadecimal values. The gantry has to be in standby mode when accessing the control system. ¹ To read out the actual temperature of the gantry, perform the following: 1. Options > Service > Local Service > Control > Table load/modify 2. Select Volatile under TABLE SOURCE. 3. In the list box TABLE NAMES select T00 4. Press Go The parameter set for the table T00 is shown. Use the slider to move to the desired information - gantry temperature [degrees C] The temperature has to be in the range of 26C +/- 4C
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97 DMS
• Environmental conditions for the DMS are: - Temperature : ¹ Check the Event log for errors and warnings concerning temperature problems. ¹ Ensure that the DMS is powered on over night. ¹ If raw data is available for the images the customer is complaining about, use Analyze to read out the temperature from the header data. This indicates the temperature at the time of data acquisition. Overview -Temperature switches
• Temp. Switch at right DMS A backplane: - Opens at 38C +/- 2% - Closes at 27C +/- 2%
• Temp. Switch at DMS B backplane: - Opens at 38C +/- 2% - Closes at 27C +/- 2%
Hints for defective channel detection
0
The following 3 types of defective channel tables are available at the system
• CheckUp tables - Generated automatically at every check-up. - An empty table is available for every check-up (temporary table). - Defects found during checkup will be stored in the check-up table. With the next checkup, this table will be empty again.
• TuneUp tables - Generated during automatic detection with the service function. - The entries are updated with the next detection under service - Only the tune-up tables may be edited manually (in case of sporadic problems). - Manually entered defects will remain permanently in the tune-up table and can only be removed manually. They have to be removed after module replacement.
• IRS tables -
At checkup, the tables are derived by merging the check-up and tune-up tables. During detection under tune-up, the irs table is derived only from table tune-up The tables are located on the ICS and are transferred at every check-up to the IRS. The information about the defects in the IRS table is derived as follows:
- for 32 x 600: all information is copied from the tune-up tables. - for 24 x 1200: all information is copied from the tune-up tables. - for all other slice combinations the information is derived from these tables
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98
DMS Additional information for defective channel detection
• After part replacement (e.g. module) or if you do not succeed removing unsatisfactory channels, delete the IRS tables in ICS as follows: 1. Go to C:\Somaris\service\datastore\icstable 2. Delete all files starting with badchannelsxxxxx 3. Start an automatic detection under service to create an actual channel status. A partial tune-up as described in the guided tours follows. Viewing the detector statistics Select Detector Statistics ¹ The number of defective elements are shown for the various collimations (tune-up and checkup). Using Reports to view details of the Defective Channels Correction 1. Open an additional window and choose Reports . 2. From the menu bar TuneUp/QA/Tests choose: TuneUp > Table Generation > Def. Channels 3. Double-click Report to view the results. ¹ Detector Statistics shows all currently defective channels. Table Editing History shows the history of the detection. - Added by Automatic Detection and - Manually Added/Removed Table Conditions shows all affected slice combinations within the IRS table. Affected Modules shows the slot as well as necessary replacements (change = has to be replaced). Comments shows additional information, in case a comment was added by the customer service engineer. Adding a comment 1. Use the slider to move down to Comments 2. You can now enter a comment for a manually patched channel. Generally used to document details in case of sporadic problems.
Separate between module and other components
0
If one ore more broken channels have been found using the guided tour or other tests, you have to find out if the problem is really caused by the module or by other components. 1. Cross module cable on DMS backplane with the neigboring one.
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99 2. Close the DMS covers and repeat the test or mode that showed errors before. ¹ If the error moves to the neighboring slot, the module or module cable is broken. Continue with step 3. ¹ If error does not move, the corresponding backplane (or DAS Controller) is defective. NOTE
A second peak may appear now in the displayed plot. This is normal with crossed/swapped module cables, if no new calibration,(e.g. a new Checkup or Setup/Calibration) has been performed prior to starting the second test run.
3. To distinguish between the module and module cable, swap the whole module cable (not crossed) with the cable of the neighboring module. Close the DMS covers and repeat the test or mode that showed errors before. ¹ If the error moves to the neighboring slot, the module cable is defective. ¹ If error does not move, the module is defective. 4. Swap module cable to its original position. 5. Run assignment test to check the addressing of the DAS Controller. ¹ If the assignment test fails, replace the DAS Controller. ¹ Replace corresponding backplane.
How to interpret the physicist’s line
0
To find the decoding for the physicist’s line, go to: - Somaris > Help > Contents and Index and - select the tabcard Search and - type in physicist’s line ¹ The explanation is shown
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100 General
4Datalink
Datalink 40
Safety
0
WARNING
[ hz_serdoc_F13G01U12M03 ]
Avoid accident and injury or damage to parts. Risk of accident and injury! ¹ Read and observe the safety information contained in the “General” section of this document and/or the “Product specific safety notes”. NOTE
Follow C-MOS guidelines when handling parts of the Data transmission path.
Notes
0
This chapter contains information on how to troubleshoot the 2 DMS data paths. Evaluate the error message and run the (Data Link Test / p. 114) to determine which path is broken (DMS A or DMS B) to the IRS G-Recs. Basic functionality: The 2 DMS data paths operate at 2.5 Gbps. The connection between both DMS and the 2 IRS Receivers is established via 2 simplex connections over a rotating high speed data ring. There is retransmission in case of missing packets or bad readings. 1. DMS A (DCON) to IRS (G-Rec) For DMS A data, the middle structure of the 3 rotating data rings is used. 2. DMS B (DCON) to IRS (G-Rec) For DMS B data, the inner most structure of the 3 rotating data rings is used.
NOTE
The data path for DMS A data uses identical parts as the DMS B data path. For debugging, the A components can be swapped with the B components. For troubleshooting, the A data can be sent via the B path. -> the fiber optic cables at the double Tx module and at the G-Recs can be swapped to use the other path.
Definitions and abbreviations
0
LEDs on Transmitters (Tx) and Receivers (Rx) 1. Green Power: “off” if power to the corresponding Tx or Rx module is missing.
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101
2. Yellow Signal: “off” if no signal or signal with low amplitude detected. 3. Orange Sync: “off” or reduced intensity if sync error detected. LEDs on G-Recs in IRS 1. Red NoSignal: “on” if no optical signal or signal with low amplitude is detected. 2. Red Error: “on” if unsatisfactory readings are detected. When a segment on the data ring is defective, the LED blinks synchronous to gantry rotation, depending on the angular position of the defect. 3. Red 8-Bit error counter Err7...0: counts unsatisfactory readings received from DCON. Abbreviations Tx -> Transmitter Electronics Rx -> Receiver Electronics DCON -> DAS Controller G-Rec -> Receiver in IRS FODL1...3 -> Fiber optic data link (connections for fiber optic cables at DCON)
General: Receivers with Revision IRS Receiver/s
0
Fig. 44: DMS Data Paths Tab. 45
TSG permanent errors DCON to IRS
Step 1
Action
• Check power at the double Tx module. a) if the green LED is “off”, -> Tx is module defective or power from PDR is missing. Check power supply. Additionally, perform the Data Link Test and check gantry error monitor for errors reported from UMAR: Power error b) If the LED is “on”, continue with step 2.
2
• Check signal at the double Tx module. a) If one or both of the yellow LEDs are “off”, -> missing optical signal from DCON/s or broken/dirty fiber optic cable connections, or Tx module defective. Clean the fiber optic cable and check again. If LED is still “off”, continue wih step 3. Additionally, perform the Data Link Test and check gantry error monitor for errors reported from UMAR: Signal error b) If the LED is “on”, continue with step 4. c) if the orange Sync LED is on, but with reduced brightness -> check quality of signal. Refer to (TSG data quality at Tx module / p. 105)
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Datalink Step
Action
3
• Check output of DCON by establishing a direct connection between DCON and G-Rec with the spare fiber optic cable. a) If Red NO Signal LED on G-Rec is “on” -> DCON defective. b) if Red NO Signal LED on G-Rec turns “off” -> DCON and G-Rec o.k. Establish the origin connection and swap the two fiber optic cables at the Tx input. If yellow LED on Tx module is “on” now, -> cable between DCON and Tx module defective. If yellow LED is still “off” -> replace the Tx module.
4
• Check power at the corresponding stationary Rx module (A or B). a) if the green LED is “off” -> Rx module defective or power from UMAS is missing. Troubleshoot the power path first. b) if the LED is “on”, continue with step 5.
5
• Check signal at the Rx module. a) if the yellow LED is “off”, -> missing signal from Transmitter, or rotating data ring defective, or receiver carrier maladjusted/defective, or Rx module defective. Continue with step 6. b) If the yellow LED is on, continue with step 7. c) if the orange sync lock LED is on, but with reduced brightness -> check quality of signal. Refer to (TSG data quality at RX modules / p. 106)
6
• Check the data ring. a) Swap the two Rx modules (Rx A and Rx B). If the error moves -> replace the Rx module. b) if error still at initial position, adjust the triple receiver carrier (refer to replacement of parts section) and check the microstrip antenna. Refer to (How to check the transmitting antenna / p. 118). If resistance of microstrip antenna is o.k -> replace the Tx module. If resistance of microstrip antenna is not ok -> replace the Rotating Data Ring. Call HSC before replacing the Data Ring.
7
• Check the connection Rx module to G-Rec. a) If red No Signal LED at G-Rec is “on” -> missing signal from Rx module, or broken/dirty fiber optic connection, or G-Rec defective. Clean the fiber optic cable and check again. If LED is still “on”, continue with step 8. b) If the LED is “off” now, run the datalink test (Data Link Test / p. 114).
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105 Step 8
Action
• Use spare cable between Rx module and G-Rec. a) If red No Signal LED at G-Rec is still “on” -> Rx module or G-Rec in IRS defective. Continue with step 9. b) If the No Signal LED is “off” now -> replace the fiber optic cable.
9
• Swap the two fiber optic cables at Rx modules or at the G-Recs in IRS. a) If errors move to the other G-Rec -> replace the Rx module. b) If error still at first G-Rec-> replace the G-Rec.
TSG data quality at Tx module
0
The orange Sync LEDs (one for each DMS) must show a noticeable increase in light intensity in a idle system, or when plugging and unplugging the fiber optic cable. Before starting troubleshooting for data quality, perform the TSG for permanent errors first. Tab. 46
TSG data quality at TX modules
Step 1
Action
• Unplug and plug the fiber optic cables at the double Tx module. a) if one Sync LED shows reduced intenisty (e.g. due to blinking at a high rate) -> DCON output broken, or broken/dirty fiber optic connection from corresponding DCON, or double Tx module broken. Clean the fiber optic cable and check again. If LED still shows reduced intensity, continue with step 2. b) If both Sync LEDs show reduced intensity (e.g. due to blinking at a high rate) -> DCON output broken, or the Tx module is defective. Continue with step 3.
2
• Check the DCON by swapping fiber optic cables at TX module. a) Swap the fiber optic cables at the TX module. If the error moves (other LEDshows reduced intensity now) -> DCON or fiber optical cable defective. Continue with step 3. b) if the error does not move, establish the original configuration and continue with step 3.
3
• Check the DCON output using a spare fiber optic cable. a) Connect FODL1 to the corresponding Tx input with the spare cable. If the orange LED is o.k. now -> replace the fiber optic cable. b) If the orange LED still shows reduced light intensity (with spare cable installed), -> DCON or Tx module defective. Continue with step 4.
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106
Datalink Step 4
Action
• Check the DCON using the indicator on rotating fastlink transmitter. a) Connect FODL1 to the rotating Tx module for fastlink data using the spare fiber optic cable. If the Sync LED at the rotating fastlink transmitter also shows reduced intensity -> replace DCON. b) If Sync Lock LED on rotating fastlink transmitter shows a noticeable increase in light intensity-> replace the Tx module.
5
• Additionally, run Data Link test. a) Check gantry error monitor in Data Link test for errors reported by UMAR: Link error. ->replace the Tx module.
TSG data quality at RX modules
0
First ensure that the quality of the data signal at the Tx module is OK (see above). When plugging the fiber optic cable into the Tx module, there must be a noticeable increase in light intensity at the orange Sync LED on both, the Tx and Rx modules, in an idle system. Tab. 47
TSG
Step 1
Action
• Unplug and Plug the fiber optic cables at the Tx module. a) if the Sync LED at one Rx module permanently shows reduced intensity (e.g. due to blinking at a high rate) -> Tx module (output) defective, or Rotating Data Ring defective, or receiver carrier maladjusted/defective, or Rx module defective. Continue with step 2. b) if both Sync LEDs show reduced intenisty (e.g. due to blinking at a high rate) -> Tx module defective.
2
• Check the Rx module/s. a) Swap the 2 Rx modules (Data Path A and B) and check the Sync LEDs. If the error moves to the other Data Path, -> replace the Rx module. b) If the error did not move, swap back the modules and continue with step 3.
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107 Step
Action
3
• Adjust the receiver carrier (refer to replacement of parts section) and check the microstrip antenna. Refer to (How to check the transmitting antenna / p. 118) a) If resistance of microstrip antenna is o.k., replace the following parts in the order shown -> 1. Tx module, 2. Receiver carrier, 3. Rotating data ring. b) If resistance of microstrip antenna is not o.k. -> replace the Rotating Data Ring. Call HSC before replacing the Data Ring.
4
• Additionally, run Data Link test. a) Check gantry error monitor in Data Link test for errors reported by UMAS: Link error. b) check for angle dependent error distribution. If error angle dependent -> replace the rotating data ring. Call HSC before replacing the Data Ring.
TSG sporadic errors in link DCON -> IRS
0
The following table describes step by step how to troubleshoot sporadic transmission problems. Tab. 48
TSG
Step 1
Action
• Check indicators for sporadic errors: a) Check for IRS warnings in the Event Log b) Check error LED counter on GRecs For detailed instructions, Refer to (Step 1 (checking) / p. 108)
2
• Debug for random transmission errors: a) Check the data ring and the fiber optic cables using the spare fiber optic cable. b) Swap the data ring channels For detailed instructions, Refer to (Step 2 (debugging) / p. 108)
3
• Localize the source of error: a) Check for errors occurring in the DMS or IRS b) Check for errors occurring at about the same gantry angle c) Search for external interference as source of error d) Search for dominant source of errors For detailed instructions, Refer to (Step 3 (localizing) / p. 109)
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Datalink
Step 1 (checking)
0
• Check indicators for sporadic errors a) Check for IRS warnings in the Event Log: The IRS SW counts the data errors encountered in a scan and generates a warning message. Check the logbook for IRS errors, only the CRC errors are significant for data transmission. Other types of errors detected by IRS, e.g. HV_DROP, are not related to data transmission. b) Check Error LED counter on G-Recs: The error counter at the G-Rec input electronics counts the CRC and synchronization errors for the duration of the scan, i.e. not only during radiation but also during the bias phase and during pauses between sequential scans. This error counter is displayed in binary code with an 8-bit red LED bar on GRec. This counter is only active during the scan with data transfer and after mode load until the scan ends. Check that the green Data LED on G-Rec is “on”, when investigating for random data transmission errors. To use this counter as a random error detector, it is necessary to load a scan (load the mode) and to perform investigations before or during the scan.
Step 2 (debugging)
0
• Debug for random transmission errors a) check the data ring and the fiber optic cables using the spare fiber optic cable - Disable gantry rotation - Use the spare fiber optic cable to connect the DCON outputs directly to the G-Rec input. - Perform exactly the same (static) scan that is subject to random errors with a normal configuration. If the random error continues to persists, the problem is within DCON or IRS. Otherwise, the debug procedure has to be refined. The fiber optic cables between DCON → slip ring or between slip ring → IRS may be partially broken or have dirty ferrules in the connectors. Especially in the gantry, the connectors may be contaminated by carbon dust from the slip ring brushes. In this case, the signal at the fiber optic cable output is lower than usual. However, the signal detect indicators may not trigger although the signal quality is poor. To isolate the problem, measure the fiber optic cable loss factors as described in the appendix and replace the fiber optic cable in case of higher losses. Alternatively, use the spare fiber optic cable to successively patch the fiber optic cable in question. If you get better results (reduced number of transitory errors or no error at all), clean the ferrules or replace the fiber. b) swap the data ring channels The data path for DMS A uses identical parts as the DMS B data path. For debugging, the A components can be swapped with the B components. For troubleshooting, the A data can be sent via the B path. ¹ Swap the fiber optic cables at the double Tx module and at the G-Recs to use the other path.
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109
Step 3 (localizing)
0
• Localize the source of error The Data Link Test automatically performs a statistical analysis regarding error distribution. Different histograms can be displayed. a) Check for errors occurring in the DMS or IRS In case of a defective DCON or G-Rec, the data errors are apparently random and apparently due to transmission. However, in reality the error occurs before transmission in the DCON and after the transmission in the G-Rec. Select Bit Errors in the Data Link Test (Data Link Test / p. 114) to get a histogram plot of the bit error position within the 16-bit data word. If the errors always occur at the same bit position(s) within the 16-bit word, when repeating the data link test: ¹ DCON or G-Rec defective, transmission across the Data Rings o.k. Example for Bit Error histogram:
Fig. 45: Error bit position histogram
b) Check for errors occurring at about the same gantry angle: Problems with the mechanical alignment of slip ring antennas can produce random errors. Select both, Data Words Error and CRC Errors in the Data Link Test to display a histogram plot of error distribution around the rotation. The Data Words Error analy-
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110
Datalink sis may be slower but it checks for every bit error. The CRC Errors analysis checks only for block errors and is faster. The example below shows errors concentrated at the same angular positions of the data ring. ¹ Rotate the gantry by hand to this angular position and check the structure for defects and mechanical alignments. (0o is X-ray tube A at 3 o’clock). Example for relation between errors and rotation angle histogram:
Fig. 46: Histogram of error versus rotation angle
c) Search for external interference as source of error: Random errors in the data path may be caused by the following external factors: -
SOMATOM Definition
Noise generated by the frequency converter for rotation Noise generated by the HV Generator Mechanical assymetries in the antenna system External equipment (e.g. therapy equipment, ovens,...)
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111 Select both the Error Bursts and Error Free Intervals in the Data Link Test to obtain two histograms that plot the error distribution within the data stream (distribution of the error burst length - EBL and error free interval - EFI). The following 3 cases show typical histograms for different error sources: Case 1 In this case both histograms have a Gauss (bell) shape. This suggests a periodic perturbation source such as the frequency inverter for gantry rotation or other power supply noise. ¹ Check the high-power connections at the generator, the grounding connection, and the high power carbon brushes. ¹ Perform tests with the rotation driver disabled or without radiation to better identify the perturbation source.
Fig. 47: Burst and EFI histogram case 1
Case 2 In this case only the burst histograms have a Gauss (bell) shape, whereas the EFI histogram decreases linearly. This suggests a non-periodic perturbation source such as external equipment operated in the vicinity of the CT examination room and generating power line interference. ¹ Check the quality of the hospital AC power lines (line transient spike analyzer) and the grounding of the CT system as well as other hospital equipment operating in the vicinity.
Fig. 48: Burst and EFI histogram case 2
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112
Datalink Case 3 In case bursts histograms are concentrated and occur at very short burst lengths, whereas the EFI histogram decreases linearly, this is suggestive of a poor signal-to-noise ratio at some fiber optic input or at the RF input for the Rx module. ¹ Check the fiber optic cables, clean the connectors, and align the receiver carrier.
Fig. 49: Burst and EFI histogram case 3
d) search for dominant sources of error: Each error source may contribute to the error budget, but only one is usually dominant. The Data Link Test is a useful tool for locating the dominant source for errors. The RF link across the data slip ring is subject to electromagnetic interference produced within the gantry. Major sources for this interference are the ring motor and its frequency inverter as well as the high-voltage generator and power supplies on the rotating gantry. In order to identify the dominant source for errors, the debug strategy eliminates one or more potential sources and investigates the way they influence error statistics. Accordingly, the data link test provides predefined test modes that deal with this debug strategy. For example, to investigate the contribution of the X-ray generator to the error budget, perform the data link test using scans without radiation. Investigate the initial error statistics: To get an idea about the initial error profile, perform the data link test with patient-like modes, i.e. modes that simulate a real scan. Use either topogram-like modes ("Static 0 deg, X-Ray" "Static 90 deg, X-Ray") or sequence-like modes ("Rot 0.33s, X-Ray"... "Rot 1.000s, X-Ray"). ¹ Try to identify if the errors are related to particular parameters such as rotation speed, tube angle, etc... Investigate the contribution of the rotation driver: To investigate the contribution of the rotation driver to the error budget, perform the data link test with the predefined modes "Static X-Ray1" and "Static X-Ray2". These modes fully disable rotation, including active braking. The frequency inverter is disabled via SW and thus generates no interference at all. This is not equivalent to switching the rotation switch OFF! These tests may be performed only in the static mode. The gantry should be positioned either via the service platform or by hand at various angular tube positions or at positions where previous tests showed an increased error proba-
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113 bility. If the error statistics change significantly as compared to previous tests, the dominant source for errors is the rotation driver and investigations should be pursued in this direction. Investigate the contribution of the X-ray generator: To investigate the contribution of the X-ray generator to the error budget, perform the data link test with the predefined modes "Rot 0.33s" ... "Rot 1.000s". These modes disable X-ray generation for various rotation speeds. Use the rotation speeds that previously showed increased error probability. If the error statistics change significantly as compared to previous tests, the dominant source for errors is the X-ray generator and investigations should be pursued in this direction. Fine tuned investigation: After having used the above steps, it may become obvious that other test mode(s) may be more suitable for checking out a particular situation. In this case, edit the user-defined test modes "Static20.dat" and "Rot20.dat" with or without X-ray to fit the particular debug needs.
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Datalink
Tests for data transmission
4.2
Cleaning a fiber optic cable
0
The cable's performance may degrade because of dust or dirt covering the input core in the cable’s receptacle.
Fig. 50: Cleaning optical connectors
Data Link Test
0
Scope
• The data link test is a sequence of scans performed automatically with the DMS configured to generate test data (assignment mode). The data received are automatically analyzed in the IRS/ICS for every incorrect bit. Error statistics are generated that allow for locating sources for error. If this test is successful, the transmission DMS to IRS is working well.
• The data link test may be performed at different rotation speeds or without rotation (ROT or STATIC modes) in the static mode with or without active braking of the gantry via the rotation driver, with radiation at different levels of X-ray power or without X-ray. How to find
•
Options > Service > Local Service > Test Tools > Sys.Communication > Data Link
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115
Fig. 51: Data link test
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116
Datalink How to use
• Perform the data link test after a careful analysis of IRS logbook errors. Search for those modes (rotation speed, X-ray power level, gantry tilt, etc...) that are most prone to transmission errors and test the data link with these particular modes. a) Press Select all, or select single modes, depending on the error pattern (e.g. rot. speed, X-ray, etc....) b) Press Go c) Wait for the Press START key to appear and then press the Start button ¹ If CRC errors or data errors are detected during the measurement, histogram evaluations can be selected. The evaluations are only available in case errors are detected (see next screenshot). For detailed informations regarding the histogram evaluations, refer to (TSG sporadic errors in link DCON -> IRS / p. 107).
Fig. 52: Data link test, possible histogram evaluations
• The analysis SW will increment an error counter for each CRC error. The total number of transmission errors is available and displayed as test result. The error counter runs over all readings into the scan that include at least five complete rotations in order to find the relationship between tube angle and error occurrence. In the case of an error counter that is not zero, its time evolution can be plotted for all scans together with the tube angle position as depicted below:
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117
Fig. 53: Example of tube angle and error count versus frames
The X axis of the plot is the reading number. The vertical axis of Channel 2 (green plot) is the number of errors. The vertical axis of Channel 1 (yellow plot) is the angular tube position (0...360oC) as explained below. Gantry angle (deg)
0
Tube A posi- 3 tion (x o’clock) from the front Tube A position from the front
30
60
90
120
150
180
210
240
270
4
5
6
7
8
9
10
11
12
East (right)
South (bottom)
West (left)
North (up)
Selectively check or uncheck the channel 1,2 checkboxes to change the vertical scale. The gantry error monitor The power, signal, and link errors reported by the Tx and Rx electronic modules in the slip ring are monitored dynamically during the scan via the UMAR on the rotating gantry and via the UMAS on the stationary gantry. These errors are the same debug signals that are indicated by the green, yellow and orange LEDs available on both Rx and Tx modules. Both UMAR and UMAS HW count the number of times these errors were activated during the scan (error counter) as well as how long the errors were active during the scan (error time). This feature is useful for identifying transitory errors that occur due to loose contacts caused by mechanical vibrations during rotation that are otherwise not detectable.
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Datalink
Appendix
4.3
How to check the transmitting antenna
0
The structures of the data rings can be measured with a digital multimeter. The figure below shows how to measure the innermost rotating data ring. The structures can be measured at the termination (see image below), and next to the transmitter 180 degrees shifted (same test points at opposite site of data ring). The results may be slightly different ~1 Ohm 1. Use a digital multimeter to measure the resistance at the following test points:
Fig. 54: Test points for rotating data rings
Measure between
Nominal value
TP1 and TP3
79 Ohm +/- 1 Ohm
TP2 and TP4
79 Ohm +/- 1 Ohm
TP1 and Ground
39.5 Ohm +/- 0.5 Ohm
TP2 and Ground
39.5 Ohm +/- 0.5 Ohm
TP3 and Ground
39.5 Ohm +/- 0.5 Ohm
TP4 and Ground
39.5 Ohm +/- 0.5 Ohm
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119 NOTE
Measuring the resistance is important to find an interrupt or short circuit in the structure. The nominal values should serve as a guideline. If the measured values are out of tolerance, call HSC before replacing the data ring.
Measuring the fiber optic signal along the link
0
The fiber optic cable power at both outputs of DCON and at the fiber optic output of the slip ring Rx module have to be high enough for reliable data transmission. The fiber optic receivers in the UMAR, slip ring Tx, and G-REC have built-in signal level detectors that report an error when the signal falls below a safe minimum level. However, for error identification it is important to know if the problem is the incoming signal or the receiving part itself. It may be possible that the power delivered via fiber optic cable to the input is high enough, however, the fiber optic receptacle in the receiver module is covered with dust or dirt, and the incoming light does not reach the destination. The fiber optic signal can be measured at any point in the link using an optical power meter (e.g. the HP 8410A or HP 8153A). The power level of the fiber optic cable should be at least -9 dBm avg. at 850 nm into a 62.5/125 MMF fiber optic cable. The modulation signal (fiber optic cable extension ratio) can be optimally measured with an oscilloscope and a fiber optic probe, e.g. Tektronix 6701B. The signal amplitude is typically 400µW. Note: A fiber optical cable mounted in the gantry is difficult to measure with the above instruments unless the cable is fully released from the gantry cable tree. To avoid this operation, you may use the spare fiber optical cable and the adapter to extend a cable end up to the measuring instrument. Consider additional loss in the spare cable to correct the final result.
Check the electrical RF signals at the Rx modules
0
The Rx modules receive RF signals via the capacitive coupling between the transmitting rotating slip antenna and the stationary receiving segment antenna. The RF coupling condition depends on the mechanical tolerances. The tests below have to be performed by manually rotating the gantry 360 degrees. Rotate the gantry by hand, check status of the LEDs at the Tx and Rx modules. Proceed as described below. Reasons why Signal detect LED on Rx module is off:
• Tx module defective (output) • Slip ring antenna system is defective or needs alignment
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Datalink • Rx module (input) is defective To check the Tx module output: Swap the fiber optic inputs of the 2 stationary Rx modules and check if the status of the signal LEDs at the Rx module changes. Additionally, replace the double Tx module with a new one. To check the slip ring antenna system: Refer to (How to check the transmitting antenna / p. 118). For alignment instructions, refer to the replacement of parts section, replacing the receiver carriers To check the RF input of the Rx module: Swap the Rx module with another Rx module and check if the status of the LEDs at the Rx modules changes.
Check the quality of data signal (jitter) at the G-REC input
0
Note: If the IRS is powered and the FPGA devices on the G-Rec are configured, the yellow DL Ready LED is blinking. If not, troubleshoot the IRS. 1. Perform the Data Link Test with the Service Platform and check the CRC error sum and data error sum counters. 2. Alternatively load a scan to activate the Error indicators at G-REC. The green DL Data LED should be “on”. Errors are detected by the G-Recs if the DL Error LED is on or blinking, and if the 8-Bit error counter increments. 3. In case of transmission errors, refer to (TSG permanent errors on DAS Controller/s -> IRS Receiver/s / p. 103).
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5Fastlink
121
50
Safety
0
WARNING
[ hz_serdoc_F13G01U12M03 ]
Avoid accident and injury or damage to parts. Risk of accident and injury! ¹ Read and observe the safety information contained in the “General” section of this document and/or the “Product specific safety notes”. NOTE
Follow C-MOS guidelines when handling data transmission parts.
Notes
0
This chapter contains information on how to troubleshoot the fastlink connections and the fastlink paths.
NOTE
All fastlink ports at the UMAR/UMAS and at the corresponding connected components are compatible. By using a patch cable, every port can be connected to any other port, to check transmit and receive functions. Every fastlink port has at least 2 LEDs that indicate the receive status. It is important always to check the LEDs at both components to determine if the problem is related to a transmit problem of the first component, or a receive problem of the other component.
The following troubleshooting guides (TSG’s) are covered in this chapter: 1. Direct fastlink connections in rotating part of gantry All rotating components connected to the fastlink are connected via the UMAR 2. Direct fastlink connections in stationary part of the gantry All stationary components connected to the fastlink are connected via the UMAS 3. Transmission Path UMAS to UMAR Data transmission between UMAS and UMAR is achieved via the stationary transmitter, the stationary data ring, and the rotating receiver assembly. 4. Transmission Path UMAR to UMAS Data transmission between UMAR and UMAS is achieved via the rotating transmitter, the rotating data ring, and the stationary receiver assembly.
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Fastlink
Definitions and abbreviations
0
Tx module-> Transmitter electronics module Rx module -> Receiver electronics module
General: Receivers with Revision clean the fiber optic cable (Cleaning a fiber optic cable / p. 134). If LEDs are still “on”, continue with step 2.
2
• Switch “off” and “on” the gantry at the control box. a) If LEDs are still “on” or blinking, continue with step 3.
3
• Check the UMAR by swapping connectors. a) Swap the fastlink connector at the UMAR with the neighboring one (e.g. swap the A-component with the B-component). If the error moves to the neighboring slot, -> UMAR o.k., fiber optic cable or the connected component defective. Swap the connectors to their original positions and continue with step 4. b) If the error does not move to the other slot, -> UMAR defective.
4
• Check the connection using a spare fiber optic cable. a) Connect the corresponding slot of the UMAR to the connected component with the spare fiber optic cable. If LEDs are still “on” -> replace the connected component. Before replacing the component, connect the component to any other fastlink port with the spare fiber optic cable, and check the LEDs to verify the defect. b) if LEDs are “off” now -> cable between UMAR and component defective.
TSG stationary fastlink connections
0
The following figure shows the stationary fastlink connections and the LEDs which are useful error indicators.
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Fastlink
Fig. 58: Stationary fastlink connections
LEDs on UMAS 1. NoSD: “On” if no optical signal, or signal with low amplitude is detected 2. Error: “On” , if Sync or CRC error detected LEDs on XGS A and XGS B in PDC (D703) 1. Light Err: “On” if no optical signal, or signal with low amplitude is detected 2. Link Err: “On” , if Sync or CRC error detected LEDs on PHS (LMAS) 1. Transceiver Signal detect: “On” if no optical signal, or signal with low amplitude is detected 2. Receive Error: “On” , if Sync or CRC error detected LEDs on IRS 1. FL NOT READY: not used 2. FL NO SIGN: “On” if no optical signal, or signal with low amplitude is detected
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3. FL NO SYNC: “On” , if Sync lost 4. FL CRC ERR: “On” if CRC error detected. In case of angle dependent errors, this LED is “on”, unless correct CRC is detected. Tab. 50
TSG stationary fastlink connections
Step
Action
1
• Check the red NoSD and Error LED at the UMAS and at the connected component. a) if one or both LEDs (Error and NoSD) are “on” or blinking at UMAS or/and at the connected component -> clean the fiber optic cable (Cleaning a fiber optic cable / p. 134). If LEDs are still “on”, continue with step 2.
2
• Switch “off” and “on” the gantry at the control box. a) If LEDs are still “on” or blinking, continue with step 3.
3
• Check the UMAS by swapping connectors. a) swap the fastlink connector at the UMAS with the neighboring one (e.g. swap the A-component with B-component). If the error moves to the other slot, -> UMAS o.k., fiber optic cable or the connected component defective. Swap the connectors to their original positions and continue with step 4. b) If the error does not move to the other slot, -> UMAS defective
4
• Check the connection using a spare fiber optic cable. a) Connect the corresponding slot of the UMAS to the connected component with the spare fiber optic cable. if LEDs are still “on” -> Replace the connected component. Before replacing the component, connect it to any other fastlink port with the spare fiber optic cable, and check the LEDs to verify the defect. b) if LEDs are “off” now -> cable between UMAS and component defective
TSG for connection UMAS -> UMAR
0
The following figure shows the fastlink path from the UMAS to the UMAR, and the LEDs which are useful error indicators.
NOTE
© Siemens, 2006 For internal use only
To find angle dependent problems, rotate the gantry by hand and check the error LED at UMAR. If the LED is “on” for specific angular positions, check the data ring first.
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Fastlink
Fig. 59: Fastlink path from UMAS to UMAR
LEDs on stationary Tx module: 1. Power: “Off” if power to the Tx module is missing. 2. Signal: “Off” if no signal, or signal with low amplitude is detected 3. Sync: “Off or reduced intensity (blinking)” if Sync or CRC error detected LEDs on rotating Rx module: 1. Power: “Off” if power to the Tx module is missing. 2. Signal: “Off” if no signal, or signal with low amplitude is detected 3. Sync: “Off or reduced intensity” if Sync or CRC error detected. LEDs on UMAR 1. NoSD: “On” if no signal, or signal with low amplitude is detected 2. Error: “On” , if Sync or CRC error detected Tab. 51
TSG fastlink path UMAS to UMAR
Step 1
Action
• Check all fastlink indicators (LEDs) in the path UMAS->UMAR. a) if one or more LEDs in the path are not in idle state, continue with step 3. b) if all LEDs are idle, continue with step 2.
2
• Check output of UMAS by establishing a direct connection between UMAS and UMAR with a spare fiber optic cable. a) If Red NoSD and Error LED at UMAR are “on” -> UMAS defective. Before replacing the UMAS, connect UMAS to any other fastlink port with the spare fiber optic cable, and check the LEDs to verify the defect. b) if Red NoSD and Error LED at UMAR are “off” -> UMAS and UMAR o.k. Establish the original connection and continue with step 3.
3
• Check power at the stationary Tx module. a) If the green LED is “off”, -> Tx module defective or power from UMAS is missing. Check the power path. b) if the LED is “on”, continue with step 4.
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129 Step 4
Action
• Check signal at the TX module. a) If the yellow LED is “off”, -> missing signal from UMAS or broken/dirty fiber optic cable connection, or TX module defective. Clean the fiber optic cable (Cleaning a fiber optic cable / p. 134). If yellow LED is still “off”, -> connect the UMAS and Tx module with the spare fiber optic cable. If the problem is not related to the cable, establish the original connection and continue with step 5. b) if the orange Sync LED is “on”, but with reduced brightness -> check quality of signal (TSG data quality at Tx modules / p. 132). c) If all LEDs are “on”, continue with step 6.
5
• Swap the Tx module. a) Swap the Tx module with the rotating one. If the error moved-> replace the Tx module.
6
• Check power at the Rx module. a) If the green LED is “off”, -> Rx module defective or power from UMAR is missing. Troubleshoot the power path first. b) if the LED is “on”, continue with step 7.
7
• Check signal at the Rx module. a) if the yellow LED is off,-> missing signal from Transmitter, or stationary data ring defective, or rotating receiver carrier defective. Continue with step 8. b) if the orange sync lock LED is “on”, but with reduced brightness -> check quality of signal. (TSG data quality at Rx modules / p. 133) c) If all LEDs are “on”, continue with step 9.
8
• Check the stationary data ring a) Measure the resistance of the stationary data ring (How to check the transmitting antenna / p. 135). If resistance not o.k., replace the data ring. Call HSC before replacing the data ring. b) Adjust the rotating receiver carrier. If the error still persists, continue with step 9.
9
• Check the connection from Rx to UMAR. a) If the red LEDs at the UMAR are “on” -> missing signal from Rx module, or broken/dirty fiber optic connection, or UMAR defective. Clean the fiber optic cable (Cleaning a fiber optic cable / p. 134). If LEDs are still “on”, establish the original connection and continue with step 10.
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Fastlink Step 10
Action
• Use the spare fiber optic cable between Rx module and UMAR. a) If red LEDs at UMAR are still “on” -> Rx module or UMAR defective. Continue with step 11. b) If the Error LED is “off” now -> Replace the fiber optic cable.
11
• Swap the Rx module with another one and check the LEDs at the Rx module and UMAR. a) If LEDs at UMAR are still “on”-> replace the UMAR.
TSG for connection UMAR -> UMAS
0
The following figure shows the fastlink path from the UMAS to the UMAR, and the LEDs which are useful error indicators.
NOTE
The UMAR->UMAS path uses the outermost structure of the rotating data ring. To isolate the data ring, the middle or inner structure (DMS A/B path) can be used temporarilly. Use the Tx module and Rx module of the DMS data path, and temporarily establish fastlink connections to check the data ring (use the spare fiber optic cables).
Fig. 60: Fastlink path from UMAR to UMAS
LEDs on rotating Tx module: 1. Power: “Off” if power to the Tx module is missing. 2. Signal: “Off” if no signal, or signal with low amplitude is detected 3. Sync: “Off or reduced intensity (blinking)” if Sync or CRC error detected LEDs on stationary Rx module: 1. Power: “Off” if power to the Tx module is missing. 2. Signal: “Off” if no signal, or signal with low amplitude is detected 3. Sync: “Off or reduced intensity” if Sync or CRC error detected. LEDs on UMAS 1. NoSD: “On” if no signal, or signal with low amplitude is detected
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2. Error: “On” , if Sync or CRC error detected Tab. 52
TSG fastlink path from UMAR to UMAS
Step 1
Action
• Check all fastlink indicators (LEDs) in the path UMAR->UMAS a) if one or more LEDs in the path are not in idle state, continue with step 3. b) If all LEDs are idle, continue with step 2.
2
• Check output of UMAR by establishing a direct connection between UMAR and UMAS with a spare fiber optic cable. a) If Red NoSD and Error LED at UMAS are “on” -> UMAR defective. Before replacing the UMAR, connect UMAR to any other fastlink port with the spare fiber optic cable and check the LEDs to verify the defect. b) if Red NoSD and Error LED at UMAS are “off” -> UMAS and UMAR o.k. Establish the original connection and continue with step 3.
3
• Check power at the rotating Tx module. a) If the green LED is “off”, -> Tx module defective or power from UMAR is missing. Check the power path. b) If the LED is “on”, continue with step 4.
4
• Check signal at the Tx module. a) If the yellow LED is “off”, -> missing signal from UMAR, or broken/dirty fiber optic cable connection, or Tx module defective. Clean the fiber optic cable (Cleaning a fiber optic cable / p. 134). If yellow LED is still “off”, connect the UMAR and the Tx module with the spare fiber optic cable. If the problem is not related to the cable, establish the original connection and continue with step 5. b) if the orange Sync LED is on, but with reduced brightness -> check quality of signal. (TSG data quality at Tx modules / p. 132) c) If all LEDs are “on”, continue with step 6.
5
• Swap the Tx module. a) Swap the Tx module with the stationary one. If the error moved-> replace the Tx module.
6
• Check power at the Rx module. a) If the green LED is “off” -> Rx module defective or power from UMAS is missing. Troubleshoot the power path. b) if the LED is “on”, continue with step 7.
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Fastlink Step 7
Action
• Check signal at the Rx module. a) if the yellow LED is “off” -> missing signal from Transmitter, or rotating data ring defective, or stationary receiver carrier defective. Continue with step 8. b) if the orange Sync LED is on, but with reduced brightness -> check quality of signal. (TSG data quality at Rx modules / p. 133) c) If all LEDs are “on”, continue with step 9.
8
• Check the rotating data ring (fastlink path). Refer to (How to check the transmitting antenna / p. 135) and readjust the stationary receiver carrier. a) Measure the resistance of the rotating data ring (fastlink uses the outermost structure). If resistance not o.k. -> replace the data ring. Call HSC before replacing the data ring. b) Adjust the stationary receiver carrier. If the error still persists, continue with step 9.
9
• Check the connection from Rx to UMAS. a) If red Error LEDs at UMAS are “on” -> missing signal from Rx module, or broken/dirty fiber optic connection, or UMAS defective. Clean the fiber optic cable (Cleaning a fiber optic cable / p. 114). If LEDs at UMAS are still “on”, establish the original connection and continue with step 10.
10
• Use spare fiber optic cable between Rx module and UMAS. a) If the red LEDs at UMAS are still “on” -> Rx module or UMAS defective. Continue with step 11. b) If the LEDs are “off” now -> Replace the fiber optical cable.
11
• Swap the Rx module with another one and check the LEDs at the Rx module and UMAS. a) If LEDs on UMAS are still “on”-> replace the UMAS.
TSG data quality at Tx modules
0
Two Tx modules are used for fastlink data transmission: one stationary Tx module for the uplink to the rotating part, and one rotating Tx module for the downlink from the rotating to the stationary part. Before starting troubleshooting for data quality, perform the TSG for the fastlink connections first.
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Tab. 53
TSG data quality at Tx modules
Step 1
Action
• Unplug and Plug the fiber optic cables at the Tx module. a) if the Sync LED shows reduced intensity (e.g. due to blinking at a high rate) -> UMAR/UMAS output broken, or broken/dirty fiber optic connection from UMAR/UMAS, or Tx module broken. Clean the fiber optic cable (Cleaning a fiber optic cable / p. 134). If LED still shows reduced intensity, continue with step 2.
2
• Check the UMAR/UMAS output using a spare fiber optic cable. a) Connect UMAR/UMAS to the corresponding Tx with the spare fiber optic cable. If the orange LED is o.k. now -> replace the fiber optic cable between UMAR/UMAS and Tx module. b) if the orange LED still shows reduced light intensity (with spare cable installed), -> UMAR/UMAS or Tx module defective. Continue with step 3.
3
• Check the UMAR/UMAS output using the indicator on any other Tx module. a) Connect UMAR/UMAS to any other TX module within the system, using the spare fiber optic cable. If the Sync Led at the temporarilly used Tx module shows also reduced intensity -> replace UMAR/UMAS. b) if Sync Led on the temporarilly used Tx module shows a noticeable increase in light intensity-> replace the corresponding Tx module.
TSG data quality at Rx modules
0
First ensure that the quality of the data signal at the Tx module is OK (see above). When plugging the fiber optic cable into the Tx module, there must be a noticeable increase in light intensity at the orange Sync LED on both the Tx and Rx modules. This condition can change at various gantry angular positions. Tab. 54
TSG
Step 1
Action
• Unplug and plug the fiber optic cables at the corresponding Tx module. a) if the Sync LED at the Rx module shows reduced intensity (e.g. due to blinking at a high rate) -> Tx module (output) broken, or broken Data Ring, or Rx module broken, or receiver carrier defective. Continue with step 2.
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Fastlink Step 2
Action
• Check the RX module/s. a) Swap the corresponding Rx module with any other Rx module (e.g. use a Rx module from Data Path A) and check the Sync LED. If the error moved to the temporarilly used Rx module, -> replace the Rx module. b) if the orange LED still shows reduced light intensity, swap back the modules and continue with step 3.
3
• Check the data ring (How to check the transmitting antenna / p. 135) and readjust the receiver carrier (refer to the replacement of parts section). a) If resistance of the microstrip antenna is o.k., replace the parts in the following order, after adjusting the receiver carrier -> 1. Tx module, 2. receiver carrier, 3. rotating data ring. b) If resistance of microstrip antenna is not o.k. -> replace the Rotating Data Ring. Call HSC before replacing the data ring.
Tests for data transmission
0
Cleaning a fiber optic cable The cable's performance may degrade because of dust or dirt covering the input core in the cable’s receptacle.
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135
Fig. 61: Cleaning optical connectors
Fastlink Test The fastlink test within the Service Platform is a quick check for the fastlink path. Select: Local Service->Sys.Communication->Fastlink This test has to pass without any errors determined by the counters. If errors are found with this test, refer to TSG for the fastlink connections in this section. How to check the transmitting antenna The structures of the fastlink data rings (stationary and rotating) can be measured with a digital multimeter. The structures can be measured next to the transmitters as shown below, and at the terminals shifted 180 degrees (same test points at opposite site of data ring). The results may be slightly different ~1 Ohm.
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Fastlink 1. Use a digital multimeter to measure the resistance at the following test points:
Fig. 62: Test points for data ring
Measure between
Nominal value
TP1 and TP3
79 Ohm +/- 1 Ohm
TP2 and TP4
79 Ohm +/- 1 Ohm
TP1 and Ground
39.5 Ohm +/- 0.5 Ohm
TP2 and Ground
39.5 Ohm +/- 0.5 Ohm
TP3 and Ground
39.5 Ohm +/- 0.5 Ohm
TP4 and Ground
39.5 Ohm +/- 0.5 Ohm
NOTE
Measuring the resistance is important to find an interrupt or short circuit in the structure. The nominal values should serve as a guideline. If the measured values are out of tolerance, call HSC before replacing the data ring.
Measuring the fiber optic signal along the link The fiber optic cable power at the fiber optic output of the slip ring Rx module has to be high enough for reliable data transmission. The fiber optic receivers in the UMAR, slip ring Tx/Rx modules, and UMAS have built-in signal level detectors that report an error when the signal falls below a safe minimum level. However, for error identification it is important to know if the problem is the incoming signal or the receiving part itself. It may be possible that the power delivered via fiber optic cable to the input is high enough, however, the fiber optic receptacle in the receiver module is covered with dust or dirt, and the incoming light does
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not reach the destination. The fiber optic signal can be measured at any point in the link using an optical power meter (e.g. the HP 8410A or HP 8153A). The power level of the fiber optic cable should be at least -9 dBm avg. at 850 nm into a 62.5/125 MMF fiber optic cable. The modulation signal (fiber optic cable extension ratio) can be optimally measured with an oscilloscope and a fiber optic probe, e.g. Tektronix 6701B. The signal amplitude is typically 400µW. Note: A fiber optic cable mounted in the gantry is difficult to measure with the above mentioned instruments unless the cable is fully released from the gantry cable tree. To avoid this operation, you may use the delivered spare fiber optical cable and the adapter to extend a cable end up to the measuring instrument. Consider additional loss in the spare cable to correct the final result.
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6Rotating Gantry
Rotating Gantry 60
Safety
0
WARNING
[ hz_serdoc_F13G01U12M03 ]
Avoid accident and injury or damage to parts. Risk of accident and injury! ¹ Read and observe the safety information contained in the “General” section of this document and/or the “Product specific safety notes”.
Notes
0
This section contains information about isolating different problems in the rotating part of the gantry.
• • • • •
Section “General” -> General information Section “CAN Bus” -> Guided steps for troubleshooting CAN bus problems Section “Stop Report” -> Guided steps for troubleshooting Stop Report problems Section “Rotating controller” -> Rotating controller tests Section “System test” -> System tests (DOM functional, X-ray timeout)
Definitions and abbreviations Tab. 55
0
Definitions and abbreviations
Term
Definition / Abbreviation
CAN
Controller area network
tbd
To be done
TSG
Troubleshooting guide
Prerequisites
0
Documents n.a Tools and auxiliary equipment
• Standard tool kit • Multimeter • Scope
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CAN Bus
6.1
CAN bus rotating part The UMAS is the master controller for the CAN bus of the rotating part. The CAN bus consists of a closed loop which is routed through certain rotating components. The terminal resistor of the CAN bus has a value of 120 ohm and is located inside of the UMAR. The 2 wires of the loop are named CAN_L and CAN_H. The CAN bus wires CAN_L and CAN_H are routed from the UMAS via the rear slip ring (2 tracks) to the UMAR. At the UMAR, the CAN bus wires are routed through XGR A/B, XDC A/B and the PDR. Because the CAN bus is a hard-wired loop connection (refer to figure), the resistance of the loop can be measured using a multimeter. The resistance at plug X401 on cable W399 between pin 2 and 10 must be 120 +30/-10 ohm. Also check that the 2 CAN wires (CAN_l/CAN_H) are insulated from ground. All affected CAN bus components are indicated in the figure below.
Fig. 63: Can bus overview - rotating part of the gantry
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Rotating Gantry
TSG CAN bus (rotating part) Tab. 56
0
CAN bus troubleshooting
Step
Action
1
• Switch system off and press service switch S1 in PDC-A to switch off gantry power completely.
2
• Remove plug X401 from UMAS. Measure the resistance at plug X401 on cable W 399 between pin 2 and pin 10 (CAN Bus / p. 139). a) If the measured resistance value is 120 +30/-10 ohm -> wiring from plug X401 cable W399 to the 120 ohm bus terminator inside of the UMAR is ok -> continue with item 3. b) If the resistance value is not 120 +30/-10 ohm -> continue with item 4.
3
• Measure the resistance at plug X401 on cable W 399 from pin 2 and pin 10 against system ground (CAN Bus / p. 139). a) If the resistance value is > 10 Kohm -> insulation on CAN_H and CAN_L wires against system ground is ok -> no further action necessary. b) If the resistance value is about 0 ohm -> insulation for CAN_H and CAN_L against system ground is not ok (short circuit to ground) -> continue with item 5.
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Step
Action
4
• Remove plug X305 from UMAR. Measure the resistance at plug X305 on the UMAR between pin 2 and pin 10 (CAN Bus / p. 139). a) If the resistance value is 120 +30/-10 ohm -> CAN bus connection between plug X305 on cable W550 and plug X401 on cable W399 has a problem. -> check wiring from plug X305 on cable W550 to plug X1 on the slip ring pin 2/10 for bad contact or broken wires. -> check wiring from plug X401 cable W399 to plug X2 on slip ring pin 2/10 for bad contact or broken wires. -> If above cable wiring is ok -> the problem is at the back slip ring (measure the continuity between plugs X1 and X2 pin 2/10 on the slip ring , check/change defective brushes....). b) If the resistance value is not 120 +30/-10 ohm -> remove plugs X302, X303, X307, X301, and X300 in sequence. At each of these plugs on the UMAR, measure the resistance between pin 4 and 11 until 120 +30/-10 ohm can be measured. -> If 120 +30/-10 ohm can be measured -> the CAN bus problem is between the last plug measured and the previously measured plug -> find by ohm measurement which part is defective and change the defective part.
5
• Remove plug X305 from UMAR. Measure the resistance at plug X401 on cable W399 pin 2/10 against system ground (CAN Bus / p. 139). a) If the insulation problem still exists -> the insulation problem is between plug X305 on cable W550 and plug X401 on cable W399. Remove parts located between above mentioned plugs in sequence to find the insulation problem. b) If the insulation problem no longer exists -> the problem is somewhere in the rotating part between UMAR and the connected components. Isolate the problem by measuring at plug X305 pin 2/10 on UMAR to system ground while removing plug X300, X301, X307 X303, and X302 in sequence.
TSG CAN bus to XGS
0
CAN bus to XGS The UMAS is the master controller for the CAN bus to the XGS. The CAN bus consists of a closed loop which is routed through XGS-A in PDC-A and XGS-B in PDC-B. The terminal resistor of the CAN bus has a value of 120 ohm and is located inside a dongle. The dongle is plugged in at XGS-B X3. The 2 wires of the loop are named CAN_L and CAN_H. The CAN bus wires CAN_L and CAN_H are routed from the UMAS to XGS-A and XGS-B. Because the CAN bus is a hardwired loop connection (see drawing below) the resistance of the loop can be measured using a multimeter. The resistance at plug X400 on the UMAS
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Rotating Gantry between pin 2 and 10 must be 120 +30/-10 ohm. Additionally, check that the 2 CAN wires (CAN_l/CAN_H) are insulated against ground. All affected CAN bus components are indicated in the figure below.
Fig. 64: CAN bus overview for XGS
SOMATOM Definition
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Rotating Gantry Tab. 57
143
CAN bus troubleshooting
Step
Action
1
• Switch system off and switch off system power using the onsite off/on switch (power of XGS-A/B is switched off).
2
• Remove plug X400 from UMAS. Measure the resistance at plug X400 on cable W55 between pin 2 and pin 10. a) If the measured resistance value is 120 +30/-10 ohm -> wiring from plug X400 on cable W55 to the 120 ohm bus terminal at X3 on XGS B is ok -> continue with item 3. b) If the resistance value is not 120 +30/-10 ohm -> continue with item 4.
3
• Measure the resistance at plug X400 on cable W55 from pin 2 and pin 10 against system ground. a) If the resistance is > 10 Kohm -> insulation of CAN_H and CAN_L wires against system ground is ok -> no further action necessary. b) If the resistance is about 0 ohm -> insulation of CAN_H and CAN_L against system ground is not ok (short circuit to ground) -> continue with item 8.
4
• Remove plug X4 from XGS-A. Measure the resistance at plug X4 on XGS-A between pin 2 and pin 10. a) If the resistance value is 120 +30/-10 ohm -> CAN bus connection between plug X4 and X400 on cable W55 has a problem. -> check cable W55 for bad contact or broken wires. b) If the resistance value is not 120 +30/-10 ohm -> continue with item 5.
5
• Remove plug X3 from XGS-A. Measure the resistance at plug X3 on the cable W54 between pin 2 and pin 10. a) If the resistance value is 120 +30/-10 ohm -> check plugs X3 /X4 on XGS-A for bad contacts; otherwise, change XGS-A. b) If the resistance value is not 120 +30/-10 ohm -> continue with item 6.
6
• Remove plug X4 from XGS-B. Measure the resistance at plug X4 on XGS-B between pin 2 and pin 10. a) If the resistance is 120 +30/-10 ohm -> check cable W54 for bad contact or broken wire; otherwise, change cable W54. b) If the resistance is not 120 +30/-10 ohm -> continue with item 7.
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Rotating Gantry Step
Action
7
• Remove plug X3 (including the 120 ohm bus terminal) from XGS-B and measure the resistance at plug X3 (dongle) between pin 2 and pin 10. a) If the resistance value is 120 +30/-10 ohm -> check plugs X3/X4 on XGS-B for bad contacts; otherwise, change XGS-B. b) If the resistance value is not 120 +30/-10 ohm > change dongle plug X3.
8
• Remove plug X3 from XGS-A. Measure the resistance at plug X3 on cable W54 pin 2/10 against system ground. a) If the insulation problem still exists -> the insulation problem is between plug X3 on cable W54 , XGS-B and dongle plug X3 on XGS-B. Remove listed parts in sequience to isolate the insulation problem. b) If the insulation problem no longer exists -> the insulation problem is between plug X400 on the cable W55 and plug X3 on XGS-A. Remove listed parts in sequence to isolate the insulation problem.
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Stop report loop
6.2
The stop report loop is a made up of a number of contacts connected in series and fed with 24 V via Relay K8. Relay K6 is normally energized as long as power is available at the UMAS. The stop loop is then set by the firmware closing K7 for 100 ms. When all stop contacts are closed, K8 will energize and be held on by its self-holding contacts. Opening one of the stop contacts will cause K8 to release.
NOTE
The Stop Report Loop LEDs on UMAS are still under construction. For this reason the troubleshooting described below is only valid in a limited manner for the current system state.
TSG stop report loop
0
If the stop report loop does not close, you may use the S8 switch on the UMAS for troubleshooting. By activating S8, the K8 contact is bridged and 24 V (30 mA) is supplied to the stop report loop. Check down the LEDs on the UMAS if the LED status is on or off. The first LED found which is not on indicates an open loop and therefore the direction of troubleshooting. For example, if LED “SR PFront” is on but “SR PDC” is the first LED switched off, the loop to the upper front segment is open. In this case you can measure the continuity of the upper front segment components until the problem (open loop) is found.
NOTE
© Siemens, 2006 For internal use only
To troubleshoot some of the components of the stop report loop, it is necessary to have a 15 pin SUB D (male and female) plug available.
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Rotating Gantry
Fig. 65: Stop circuit Tab. 58
Stop report troubleshooting
Step
Action
1
• Switch on service switch S8 on UMAS (use a small tool to switch on S8).
2
• Check status of the following stop report loop LEDs on UMAS in the following ascending order. a) SR PFront b) SR PDC c) SR UMAS d) SR PRear e) SR Con-Box f) SR CTRLRot If a LED is on -> loop to the belonging component loop is ok. The first LED which is switched off indicates that the corresponding component loop is open. Troubleshoot in this direction. a) If all LEDs are off -> continue with item 3. b) If the first LED which is not lit is SR PFront -> continue with item 4. c) If the first LEDs which is not lit is SR PDC -> continue with item 5. d) If the first LED which is not lit is SR UMAS -> continue with item 6. e) If the first LED which is not lit is SR Con-Box -> continue with item 7. f) If the first LED which is not lit is SR CTRLRot -> continue with item 8. g) If all LEDs are on -> continue with item 9.
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Step 3
Action
• UMAS internal problem or missing 24 V at UMAS. a) Check if 24 V LED is lit on UMAS -> if not, 24 V from PD-A is missing b) Press push button S5 (activates K11) and check if LED “SR PFront” switches on. c) Change UMAS
3
• Open stop loop at upper front segment components (panels, display, MV45, wiring). Measure the continuity of the loop in sequence until the problem is found. a) Measure the continuity from pin 1 to 14 at plug X403 on cable W357. Measure the continuity from pin 1 to 14 at plug X307 on cable W250. Measure the continuity from pin 1 to 14 at plug X2 on cable W252 Measure the continuity from pin 1 to 14 at plug X2 on cable W254 Measure the continuity from pin 1 to 14 at plug X2 on cable W256
4
• Open stop loop to XGS-A or XGS-B a) Measure the continuity between plug X400 on cable W54 pin 1/9 to X4 (W54) pin 1/9. b) Switch service switch S8 on the UMAS to off (normal position). Install Sub D plug with bridged pin 1 and 9 onto plug X3 on XGS-A (simulate stop loop to XGS-B). Switch system on and check whether LED “SR PDC” is on or not. -> If LED SR2 is on -> open loop to XGS-B -> If LED SR2 is still off -> open loop in XGS-A
5
• Open stop loop from internal UMAS FPGA. There are different reasons that the FPGA opens the stop loop. Perform a restart and/or check logbook for other error messages that have caused the FPGA to open the stop loop. a) Switch system off. Press service switch S1 in PDC A to switch UMAS off. Restart system. b) Check logbook for error messages that have caused the FPGA to open the stop loop. Follow the troubleshooting instructions described in the error messages. c) Change UMAS.
6
• Open stop loop of the back ring components (panels, MV45, wiring). Measure the continuity of the loop in sequence until the problem is found. a) Measure the continuity from pin 1 to 14 at plug X404 on cable W358. Measure the continuity from pin 1 to 14 at plug X308 on cable W251. Measure the continuity from pin 1 to 14 at plug X2 on cable W255 Measure the continuity from pin 1 to 14 at plug X2 on cable W257
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148
Rotating Gantry Step 7
Action
• Open stop loop to the control box. Measure the continuity of the loop in sequence until the problem is found. a) Measure the continuity from pin 1 to 9 at plug X402 on cable W51 .
8
• Open stop loop from the rotating part of the gantry. First measure the continuity between plug X401 on the UMAS and plug X305 on the UMAR. Then exclude components using of a Sub D plug with bridged pins 1 and 9. a) Measure the continuity between plug X401 on cable W399 (pin 1/9) via the slip ring part to plug X305 on cable W550 (pin 1/9). b) Switch off service switch S8 on the UMAS (normal position). Install Sub D plug bridged between pin 1 and 9 in sequence onto plugs X302, X303, X301, and X300 on the UMAR (simulate loop to the connected components). Switch system on and check if the stop circuit is ok when the bridged Sub D plug is installed. Perform above steps on all above mentioned plugs. -> If the stop loop closes -> the problem is caused by the component which is normally connected to the plug where the dummy Sub D plug is connected at the moment. -> If the stop loop does not close -> FPGA stop report loop on UMAR is open. There are different reasons that the FPGA opens the stop loop. Check the Eventlog for error messages that have caused the FPGA to open the stop loop. Follow troubleshooting instructions given in the error messages to continue. -> Change UMAR.
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Rotating controller
6.3
DOM
0
The functionality of the Dose Modulation Control is tested. It contains the following subtests: Self-Test: The self-test of the DOM controller is performed via the test interface. Performing the DOM test 1. Select Local Service -> Test Tools -> Rot. Controller -> DOM 2. Select unset all. 3. Select relevant tests. 4. Click GO and follow the instructions in the dialog. The test is terminated automatically. Tab. 59
DOM test
Step 1
Action If test fails, change UMAR.
COC (Tube collimator)
0
Tube collimator test function The tube collimator is used for:
• collimation of the fan beam • improving image quality (beam hardening) with movable head filter • measuring the dose value -> PHI-Z-monitor
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Rotating Gantry • controlling the flying focus position in the tube -> Phi-Z-monitor To test the function of the tube collimator, the “COC” test is available in Local Service. The test checks the function of the Phi-Z monitor in the tube collimator as well as the tube collimator function itself. PHI-PSD Signal test (lab only): A positive and negative current can be selected in the test platform. The selected current is applied via an amplifier to the A/D converter. The output of the A/D converter is checked. Z-PSD Signal test (lab only): A positive and negative current can be selected in the test platform. The selected current is applied via an amplifier to the A/D converter. The output of the A/D converter is checked. Collimator test: No actual mechanical blade movement test, instead encoder values of last INIT or last fatal TCO error (forces a TCO INIT run) are used. If values are in tolerance, this test was successful. Test can be used to check if the last encoder values were ok. It does not test the actual TCO status - see TSG instructions on how to check the actual blade movement. Filter test: Test moves the head filter to the in/out end position indicated by two LEDs. Repetitions can be selected and sporadic problems detected - see TSG instructions.
Tube collimator TSG Tab. 60
Tube collimator TSG
Step
Action
1
Switch gantry off/on (COMP/ON -> SYS/ON) to trigger a gantry INIT. During INIT, check if the TCO blades are moving and if the movable head filter position LEDs “F1 POS 1” and “F1 POS 2” are alternately switching on/off (in/out end position of head filter indication). - if above conditions are fulfilled -> continue with item 2 - if the TCO blades are not moving or seem to move incorrectly -> continue with item 3 - if TCO head filter LEDs are not alternately switching on/off -> continue with item 4
2
Check Eventlog for error messages (power supply, etc.) during INIT test if error messages are found -> continue troubleshooting as described in the error message text if no error message is found -> no further action
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Step 3
Action Check Eventlog for error messages (power supply, etc.) if error messages are found -> continue troubleshooting as described in the error message text if no error message is found -> change TCO
4
Select some repetitions in the COC filter test and check the Eventlog for the error messages (power supply, etc.) that appeared during the filter test. if error messages are found -> continue troubleshooting as described in the error message text if no error message is found -> change TCO
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Rotating Gantry
System Tests
6.4
DOM functional
0
For the dose modulation test the system phantom is used. After the phantom is positioned correctly two measurements (with both systems) are performed. The first measurement is performed without dose modulation, the second with dose modulation. After each measurement the effective mAs-product is read from generator table (control table). The images are reconstructed and displayed. After the reconstruction, an ROI is positioned in each image and the noise is retrieved. A computation concerning noise and mAs-product of both images determines whether the dose modulation works correctly or not. If a tube arcing has occurred, the test is not valid and must be repeated. The test can be done for both systems separately. Function: The DAS controller generates a DOM data frame for use in dose modulation functions. A DOM frame is a compressed version of any IRS reading sent to UMAR via Fastlink. The UMAR builds an angular attenuation profile used to modulate on-line the radiation profile (Dose) applied to the patient. From the radiation profile, the filament data are calculated and sent via Fastlink to the XGR (FilPower). Most of the DOM function in UMAR is software. Performing the test 1. Select Local Service -> Test Tools -> Rot. Controller -> COC 2. Select unset all. 3. Select relevant tests. 4. Click GO and follow the instructions in the dialog. The test is terminated automatically. If a test fails, follow the TSG described next. DOM functional TSG Tab. 61
DOM functional TSG
Step 1
Action Perform Dom functional test 5 times. -> if the test is out of tolerance at least 3 times -> continue with item 2. -> if test is not out of tolerance at least 3 times -> no action necessary
2
Perform DOM test “Local Service -> Test Tools -> Rot. Controller -> DOM” -> if DOM test is out of tolerance -> change UMAR -> if DOM test is ok -> continue with item 3.
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Step
Action
3
Check image quality from normal scans without selected DOM function. -> if image quality is ok -> UMAR DMS communication ok -> continue with item 4. -> if image is not ok -> troubleshoot Fastlink communication UMAR -> DMS (Fastlink / p. 121).
4
Troubleshoot Fastlink communication UMAR -> XGR (Fastlink / p. 121).
X-ray timeout test
0
This test checks if the scan is switched off after 108% scan time. Normally a scan is switched on/off only from the XC (X-ray release) signal, which is sent at scan start from UMAR to XGS/XGR. For safety reasons, a timer in XGS/XGR is started as soon radiation is switched on (> 20 kV) triggered from the XC signal. If the XC signal is not switched off before the internal XGS/XGR timer exceeds its 108% limit, the scan is switched off by the internal timer. If the test fails at XRS_113, (XGR Scan Time Exceeded) is sent to the Eventlog. Performing the test 1. Select Local Service -> Test Tools -> System tests -> Xray timeout 2. Select unset all. 3. Select relevant tests. 4. Click GO and follow the instructions in the dialog. The test is terminated automatically. If a test fails, follow the TSG described next. X-ray timeout TSG Tab. 62
Xray timeout TSG
Step 1
© Siemens, 2006 For internal use only
Action Check the Event log for the XRS_113 error message. Follow the instructions given in the error message text.
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154 General
7Stationary Gantry
Stationary Gantry 70
Safety
0
WARNING
[ hz_serdoc_F13G01U12M03 ]
Avoid accident and injury or damage to parts. Risk of accident and injury! ¹ Read and observe the safety information contained in the “General” section of this document and/or the “Product specific safety notes”.
Notes
0
This section contains information about isolating different problems in the stationary part of the gantry.
• Section “General” -> General information • Section “CANopen Bus” -> Guided steps for troubleshooting CANopen bus problems
• Section “Stationary controller tests ” -> Information about staionary controller tests
Definitions and abbreviations Tab. 63
0
Definitions and abbreviations
Term
Definition / Abbreviation
CAN
Controller area network
TBD
To be done
Prerequisites
0
Documents n.a Tools and auxiliary equipment
• Standard tool kit • Multimeter • Scope
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CANopen Bus
7.1
TSG CAN open bus
0
The UMAS is the master controller for the CANopen bus. The CANopen bus consists of a closed loop which is routed through certain components (refer to diagram). The terminal resistors of the CANopen bus have a value of 120 ohms and are located inside the SCR and the PHS. In addition, the control box is connected via a “repeater” (part of the UMAS board) to the CANopen bus. Therefore, the control box contains a 120 ohm terminal resistor as well.
NOTE
The CANopen bus can be checked by measuring the resistance of the CANopen circuit.
Fig. 66: CANopen bus
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Stationary Gantry Tab. 64
Sequence to measure the CANopen loop resistance:
Step
Action
1
• Switch off the system and press the service switch S1 in PDC A to switch off gantry power.
2
• Remove one of the CANopen circuit connectors. For troubleshooting, it is recommended to remove a CANopen circuit connector located in the middle between the two terminal resistors (refer to step 18 of the CANopen pin list). Measure the resistance in both directions from the CANopen circuit. Plug located at the component and the plug located at the cable.
3
• Measure the CANopen loop resistance between the CANopen_H pin and the CANopen_L pin (refer to the CANopen pin list). The resistance between the CANopen_H pin and the CANopen_L pin must be 120 +30/-10 ohm.
4
• Measure the ground resistance of the CANopen_H pin and the CANopen_L pin against system ground. Note: The CANopen circuit must be isolated against system ground. The ground resistance must be greater than 10 Kohm.
5
• If the measurement values (in both directions) are in tolerance, the CANopen circuit is o.k.
• If a measurement value is out of tolerance, remove the next CANopen connector in the direction where the measurement value is out of tolerance. Repeat the measurements from step 4 and step 5. Tab. 65
Pin list for CANopen bus
Step
Component Connector
CANopen_H pin
CANopen_L pin
Remark
1
SCR
X5
7
2
120 ohm
2
WCS
X4
1
2
3
WCS
X3
1
2
4
UMAS
X472
1
2
5
UMAS
X404
15
2
X308
15
2
6 7
PRR
X1
15
2
8
PRR
X2
15
2
9
PRL
X1
15
2
10
PRL
X2
15
2
11
MV45
X1
15
2
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Step Component Connector
CANopen_H pin
CANopen_L pin
12
MV45
X1
16
4
13
PRL
X2
16
4
14
PRL
X1
16
4
15
PRR
X2
16
4
16
PRR
X1
16
4
X308
16
4
17 18
UMAS
X404
16
4
17
UMAS
X403
15
2
X307
15
2
18 19
PFR
X1
15
2
20
PFR
X2
15
2
21
DF
X1
15
2
22
DF
X2
15
2
23
PFL
X1
15
2
24
PFL
X2
15
2
25
MV45
X1
15
2
26
MV45
X1
16
4
27
PFL
X2
16
4
28
PFL
X1
16
4
29
DF
X2
16
4
30
DF
X1
16
4
31
PFR
X2
16
4
32
PFR
X1
16
4
X307
16
4
33 34
UMAS
X403
16
4
35
UMAS
X471
1
2
36
PHS
X702
7
2
Remark
120 ohm
CANopen bus repeater (part of the UMAS board) 37
UMAS
X402
10
2
38
Control Box
X1
10
2
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158
Stationary Gantry
Stationary controller tests
7.2
The system has to be in standby mode to perform the following controller tests. Some controller tests, such as GSV, PHS, and CPI are not available or functioning with VA10.
Prerequisites
0
n.a
Master stationary (MAS) test
0
Test of foot switch and external trigger 1. Select Local Service -> Test Tools -> stat.Controller -> MAS 2. Select one or all MAS tests. 3. Click “Go” on the virtual user panel. Follow the instructions in the dialog. 4. Click the Start button at the control box. If check fails -> follow instructions in the table below. Tab. 66
MAS TSG
Step 1
Action
• Check/change footswitch or cable connection.
Gantry panel control (GPC) test
0
Test of control box, gantry panel, and gantry display. 1. Select Local Service -> Test Tools -> stat.Controller -> GPC. 2. Select one or all GPC tests. 3. Click “Go” on the virtual user panel. 4. Click the Start button at the control box and follow the instructions in the dialog. If check fails -> follow instructions in the table below. Tab. 67
GPC TSG
Step 1
Action
• Change part that was functioning incorrectly.
Rotation control (ROT) test (only max. speed limit test, 0.33 sec.)
0
Test of speed limit 0.33 sec. 1. Select Local Service -> Test Tools -> stat.Controller -> ROT. 2. Select one or all ROT tests.
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3. Click “Go” on the virtual user panel. 4. Click the Start button at the control box and follow the instructions in the dialog. If check fails -> follow instructions in the table below. Tab. 68
GPC TSG
Step
Action
1
• Check for ROT error messages in the Eventlog. Follow the instructions given in the error message.
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Cooling System 8-
Cooling System
0
Water Cooling
0
8Cooling System
General The water cooling system provides heat dissipation for the gantry electronics and X-ray tube to a central facility chilled-water system or to an “Air-Water Split Cooling Unit” (option). The internal air temperature of the gantry is regulated by a motor-driven 3-way bypass valve on the incoming cold water and by a variable-speed blower fan on an air/water heat exchanger (radiator) where the facility-chilled water flows through. Both are controlled by an electronics box containing control boards and connected to sensors for the water and air. The electronics box connects to the system via the CANopen bus. The fan unit contains its own fan motor control board that connects to the electronics box. The blower in the lower right gantry stand cools all rotating parts; there are no other fans in the rotating gantry. A condensate-collection system collects condensed water below the radiator and automatically pumps it away to a drain. The condensate pump connects electrically to the electronics box. If the temperature in the gantry or the temperature of the incoming water exceeds limits according to the sensors, the electronic box will issue messages via the CANopen bus to the UMAS that then appear in the EventLog of the ICS. For sites using the Water-Air Split Cooling Unit, an interface to it is provided on the electronics box (X6). The following diagrams are from the Function Description.
Fig. 67: Water Cooling Overview
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161
Fig. 68: Water Cooling System in Gantry
Fig. 69: Gantry water cooling circuit
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162
Cooling System
Fig. 70: Water Cooling Electronic Box Block Diagram
TSG Water Cooling General troubleshooting process steps: 1. If possible, try to determine if the problem is EXTERNAL or INTERNAL to the gantry by looking at the EventLog, Current Cooling State shown in Table T00, and LEDs on the electronics box. If the problem appears to be external, seek possible resolution in hospital/facility-chilled water system or with Split Air/Water Unit (Option), depending on which is used at the site. Continue to evaluate the internal gantry conditions if the external ones are verified as OK or cannot be determined immediately. 2. If the problem is INTERNAL to the gantry, look at the EventLog, Current Cooling State shown in Table T00, observe the LEDs on the electronics box, and use the laptop service connection to the electronics box described below. 3. Replace suspected defective parts.
NOTE
SOMATOM Definition
Always be aware that if you open the cooling pipes, you must prepare for preventing spills and refilling. If connected to the hospital/facility cooling system, contact the facility engineering personnel!
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163
Information sources The following sources of information about the source for cooling problems are available: 1. Messages in the EventLog: Review the EventLog for warning and error messages from the WCS and troubleshoot based on these errors. You can filter the EventLog on the text “COOLING” to see only cooling errors. ¹ If you cannot access the EventLog for any reason, due to a faulty ICS or CANopen connection for example, you can connect a service laptop directly to the cooling electronics box (# 4 below). The following two INFORMATION messages in the EventLog are useful to determine possible changes in the cooling conditions, even if there are no warning or error messages.
NOTE
These messages are INFORMATION-priority and will not display in the EventLog Viewer unless you have INFO messages turned on. Also, they are generated only when a certain amount of change has occurred in one of the measured values. For a readout of the current state of these values, see Step 2, “Table T00” shown below.
Message about the ENVIRONMENT/PRIMARY SIDE:
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Cooling System
Fig. 71: Message MAS220
Message about the COOLING SECONDARY (GANTRY) SIDE:
Fig. 72: Message MAS212
To determine what value is being displayed, look at the P1 value in the actual message shown in the EventLog and find this HEX number on the list of “Parameter 1: Supervision ID numbers” in the expanded message (above). P3 & P4 show the actual value in HEX.
NOTE
SOMATOM Definition
It is necessary to convert HEX to decimal to read the value. Use the Windows Calculator in the Scientific mode (WinXP Programs > Accessories > Calculator > View > Scientific). Click the HEX button, enter the values of P3 and P4 in order, then click the DEC button. Remember that temperature values are given in 1/10th degree (e.g., 247 = 24.7 degrees C).
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2. Current system cooling status using table T00: Using the Service Software function Control > Table Load/Modify, open table “T00” from “Volatile.” The current state of the various sensors is shown in the data fields of T00. Compare this to the nominal values shown in the following screen-shot to determine if the actual values displayed reveal any strong deviations and troubleshoot these.
NOTE
DO NOT change the values in any of the tables!
Fig. 73: T00 table for water cooling
© Siemens, 2006 For internal use only
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Cooling System 3. LEDs on WCS electronics box: The three LEDs on the left side of the electronics box are status indicators. In the normal mode of operation, only the green LED (H1) flashes. The yellow LED (H2) is illuminated if a warning (e.g., temperature out of tolerance) occurs, and also briefly whenever the control board is switched on (initialization). During a fault condition (e.g., fan error), the red LED (H3) is on continuously. 4. Additional information: Laptop service connection to electronics box Note: All messages mentioned below are also sent to the Eventlog. Therefore the laptop connection should be used only by someone who is familiar with a terminal emulator program. Connect the laptop PC serial port to the service connector on the electronics box with a null-modem cable and running a terminal emulator program such as HyperTerminal. Example: >sta >UpTm: 54:46 C:1 E:0 LE:250 I/Yf:6000/290 LA:200 I/Ym:0/0 Pos:0WE: 100 WA:150 FS:584 The number after the letter E: indicates the warning or error message code. E:0 indicates no warning or fault. Warning Alarms (YELLOW LED on electronics box illuminated):
SOMATOM Definition
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Code 10 / 110
Warning messages via the laptop Cooling unit exhaust air temperature (into gantry) too low
• Control valve - electrical connection is faulty - Check wiring connection at valve.
• Control valve isn’t working - Try turning the valve knob manually; see if it responds by returning to its original position. If so, probably OK (repeat several times). If it does not return to its original position, replace valve drive unit, electronics box, sensors, valve. 11 / 111 20 / 120
Exhaust air temperature of cooling unit (into gantry) is too high
• Same cause/action as code 10 above. Hospital supply water temperature is too low (
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