04 Axes and Drives
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Axes and Drives in SIMOTION
SIMOTION Siemens AG 2012. All rights reserved.
Date: File:
09.02.2012 MC-SMO-SYS_05.1
Content
SITRAIN Training for Automation and Drive Technology
Page
Connecting Electrical Drives ............................................................................................................... Symbolic Assignment Between Control and Drive ............................................................................. Automatic or Manual Message Frame Selection ................................................................................ Structure of Standard Message Frames (1) ....................................................................................... Structure of Standard Message Frames (2) ....................................................................................... Overview: Drive Coupling ................................................................................................................... Technology Objects (TO) in SIMOTION ............................................................................................ The "Axis" Technology Object ........................................................................................................... Creating and Configuring an Axis ...................................................................................................... The Basic Configuration of an Axis .................................................................................................... Selectively Removing Drive Enable Signals ................................................................................... Calling the Expert List ......................................................................................................................... Specifying Mechanical Data ............................................................................................................... Parameterizing Default Settings ......................................................................................................... Specifying Limit Switches and Maximum Velocities .......................................................................... Specifying the Maximum Acceleration and Jerk ................................................................................ Filtering the Actual Value for Master Value Coupling ......................................................................... Position Control in SIMOTION ........................................................................................................... Position Controller Optimization without Precontrol ........................................................................... Position Control with Precontrol ........................................................................................................ Selecting a Suitable Balancing Filter Type ......................................................................................... Optimizing the Balancing Time Constant (vTc) ................................................................................. Position Control with DSC – the PROFIdrive DSC Structure ............................................................ Position Controller Optimization with Precontrol and DSC ................................................................ SITRAIN Training for
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MC-SMO-SYS Axes and Drives in SIMOTION
Axes and Drives in SIMOTION
SIMOTION Siemens AG 2012. All rights reserved.
Date: File:
09.02.2012 MC-SMO-SYS_05.2
Content
SITRAIN Training for Automation and Drive Technology
Page
Dynamic Adaptation for Synchronous Axes ...................................................................................... Checking the Dynamic Adaptation Using the Circularity Test ............................................................ Positioning and Standstill Monitoring ................................................................................................. Open-Loop Speed Controlled Motion - Standstill Signal .................................................................... Following Error and Velocity Error Monitoring ................................................................................... Signal Flow Representation of the Closed-Loop Axis Control ........................................................... Programming Traversing Motion ....................................................................................................... Enabling and Disabling Axes ............................................................................................................. Processing Motion Commands .......................................................................................................... Transitional Behavior of Motion Commands ..................................................................................... Program Advance for Motion Commands .......................................................................................... Synchronous and Asynchronous Program Execution ........................................................................ Dynamic Settings for the Positioning Command ............................................................................... Start axis, Closed-Loop Position or Speed Controlled ...................................................................... Stop Axis ........................................................................................................................................... Continue Motion ................................................................................................................................. Homing Axes with Incremental Measuring Systems ........................................................................ Active Homing with/without Zero Mark . . . ........................................................................................ Passive Homing with/without Zero Mark . . . ..................................................................................... Adjusting an Absolute Encoder ......................................................................................................... Setting the Reference System .......................................................................................................... Diagnostics of Axes or Drives - Service Overview ......................................................................... Diagnostics of a TO - Querying the System Variables ...................................................................... Significance of the Service Display ................................................................................................... SITRAIN Training for
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Page 2
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MC-SMO-SYS Axes and Drives in SIMOTION
Axes and Drives in SIMOTION
SIMOTION Siemens AG 2012. All rights reserved.
Date: File:
09.02.2012 MC-SMO-SYS_05.3
Content
SITRAIN Training for Automation and Drive Technology
Page
Technological Alarms ....................................................................................................................... Configuring Technological Alarms ..................................................................................................... Acknowledging Technological Alarms ............................................................................................... Using the Technology Object Trace (1) ............................................................................................ Using the Technology Object Trace (2) ............................................................................................ If You Want to Know Even More ........................................................................................................ Using Axis Data Sets ........................................................................................................................ 2. Adding an Encoder to an Axis ....................................................................................................... Basic Configuration - Encoder Type and Mode ................................................................................. Mode of Operation of an Incremental, Optical Sin/Cos Encoder ...................................................... Settings for Incremental Encoders - "Cyclic Actual Value" ................................................................ Mode of Operation of an Absolute Encoder ...................................................................................... Settings for Absolute Encoders - "Absolute Actual Value" ................................................................ Settings for Absolute Encoders - Encoder Type ............................................................................... Settings for Travel to Fixed Endstop ................................................................................................. Travel to Fixed Endstop - "Determining the Reference Torque" ...................................................... Travel to Fixed Endstop - "Settings in the Command" ......................................................................
SITRAIN Training for
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Page 3
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MC-SMO-SYS Axes and Drives in SIMOTION
Connecting Electrical Drives For example
....via PROFIBUS-DP
MASTERDRIVES MC ... via PROFINET
SINAMICS S120
... via analog or stepping motor interface SIMODRIVE 611U
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.4
SITRAIN Training for Automation and Drive Technology
Interface to the drive
The functional interface to the drive is the speed setpoint interface. Digital as well as analog, electric drives can be directly connected to a SIMOTION C2xx. For SIMOTION P350 and SIMOTION D4x5, digital drives can be directly connected via PROFIBUS or PROFINET – and analog drives via ADI4 or IM174.
Drives on PROFIBUS/ PROFINET
With connection via PROFIBUS or PROFINET all data between the drive system and SIMOTION are exchanged via this medium. Standard message frames are used to enter the setpoint for digital drives connected to PROFIBUS as well as the feedback data from the encoder. It goes without saying that the drive must also support the selected message frame type. The type of selected message frame defines the maximum supported functionality of an axis. It goes without saying that in SIMOTION, the axis can only execute the functions, which the connected drive also supports. Axes that are operated in the positioning mode must be connected via the isochronous PROFIBUS or via PROFINET IRT to ensure correct functioning. It is sufficient for simple speed-controlled applications to be connected to a "not isochronous" PROFIBUS DP or a PROFINET RT. In this way you can connect all standard DP slaves that do not support isochronous operation.
Analog drives/ stepping motors
analog drives can be directly connected at C2xx or via PROFIBUS at the ADI4 or IM174. In this case the speed controllers are supplied with +/- 10 V via the analog outputs. The position actual values can either be taken from the encoder connected to SIMOTION C or ADI4, or from the pulse encoder emulation of the converter. The corresponding digital I/Os are available for feedback signals and controller enable signals. From V3.2 and higher, stepping motors can also be directly connected to the C2xx.
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Page 4
MC-SMO-SYS Axes and Drives in SIMOTION
Symbolic Assignment Between Control and Drive Advantages
Communication between an axis and drive is automatically set up (PROFIdrive axis message frames as well as addresses)
Message frame extensions and interconnections in the drive are dependent on the selected TO technology (e.g. SINAMICS Safety Integrated)
Axes and drives can be independently configured from one another
Communication connections are automatically established when configuring I/O on SINAMICS I/Os
The assignment is kept even for address offsets
Activating/deactivating via the menu command: Project -> using a symbolic assignment
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.5
Interconnection control
SITRAIN Training for Automation and Drive Technology
New in V4.2
The most significant innovation in the SIMOTION SCOUT engineering system is the significantly simplified connection to the SINAMICS drive system. With this step, users are supported as a result of the essentially automated integration of drives and their associated elements in SIMOTION SCOUT. Up until now, to connect drives according to PROFIdrive, users had to configure the appropriate communication, both on the drive side as well as on the control side. As result of the new symbolic assignment of technology objects (TOs) and I/Os to drive objects (Drive Objects/DOs), users no longer have to involve themselves in the PROFIdrive communication with message frames and addresses. The engineering system now takes care of all this. For "Save and compile changes" or at the latest before a download, message frames and addresses are automatically generated. Users only have to download the project data into the target system.
New control
The symbolic assignment is now realized using a new interconnection control. It is supported by technology objects – axis, external encoder, cams, cam track and measuring input. Further, the onboard I/Os of the devices SIMOTION D, CX32/CX32-2, Control Units for SINAMICS S120 as well as the Terminal Modules and TB30 can now be symbolically assigned. In this dialog, all pass-capable partners are hierarchically listed; connections are realized symbolically by simply selecting the components to be interconnected. SINAMICS drives and/or devices and terminal modules with their available I/Os can be selected in the control. In this case, only the pass-capable elements are listed with symbolic identifiers; whereby even the terminal designations of the modules are listed.
Note
If a project is upgraded to SIMOTION device firmware version V4.2 SP1, then the symbolic assignment can be subsequently selected. The assignments are automatically determined from the logical addresses. Individual TOs and DOs can be excluded from the symbolic assignment (refer to the next page)
SITRAIN Training for
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Page 5
MC-SMO-SYS Axes and Drives in SIMOTION
Automatic or Manual Message Frame Selection
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.6
SITRAIN Training for Automation and Drive Technology
PROFIBUS/ PROFINET coupling
With the coupling via PROFIBUS/PROFINET, all information between the drive system and SIMOTION is exchanged using standard message frames according to the PROFIDRIVE profile V4.0. The structure and type of the information being exchanged uniquely defines the number of the message frame.
Message frame selection
In the "Settings for ....." dialog, you can switch over to automatic or user-defined PROFIdrive message frame setting and/or automatic message frame extension for the selected drive object. Automatic PROFIdrive message frame setting: This setting (standard) is selected if the drive unit is to participate in the "Symbolic assignment" with SIMOTION. A PROFIdrive message frame (including message frame extension) is automatically determined with "Save and compile". You must configure PROFIsafe message frames yourself; the configuration of the safety data block (SIDB) however is performed automatically. User-defined: The following options are available for the user-defined setting of the process data transfer: • Semi-automatic message frame configuration (selection: "Automatic message frame extension" and "Permit automatic address adaptation". With this setting, the PROFIdrive message frame is selected, necessary message frame extensions and address adaptations are performed by the system when "Save and compile" is selected. • Manual message frame configuration: With this setting, you select the PROFIdrive message frame and the message frame extension yourself, but leave the address adaptation to the system (select. "Permit automatic address adaptation").
SITRAIN Training for
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Page 6
MC-SMO-SYS Axes and Drives in SIMOTION
Structure of Standard Message Frames (1) PZD number Setpoint
1 CW 1
2 NSET_A
PSD number Setpoint
1 CW 1
2 3 NSET_B
4 CW 2
PZD number Actual value
1 STW 1
2 NACT_A
PSD number Actual value
1 STW 1
2 3 NACT_B
4 STW 2
Standard message frame 1 (16 bit nset) Standard message frame 2 (32 bit nset, without encoder) PSD number Setpoint
1 CW 1
2 3 NSET_B
4 CW 2
5 Enc1_CW
PSD number Actual value
1 STW 1
2 3 NACT_B
4 STW 2
5 Enc1_STW
6 7 Enc1_XACT 1
8 9 Enc1_XACT 2
Standard message frame 3 (32 bit nset, with encoder) PSD number Setpoint
1 CW 1
2 3 NSET_B
4 CW 2
5 Enc1_CW
6 Enc2_CW
PSD number Actual value
1 STW 1
2 3 NACT_B
4 STW 2
5 Enc1_STW
6 7 Enc1_XACT 1
8 9 . . . Enc1_XACT 2
10 Enc2_STW
11 12 Enc2_XACT 1
13 14 Enc2_XACT 2
. . .
Standard message frame 4 (32 bit nset, with 2 encoders)
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.7
SITRAIN Training for Automation and Drive Technology
Standard message frame 1
Is designed for simple speed-controlled applications. The message frame has a control and a status word via which the basic functionality regarding activation, deactivation, pulse and controller enable is handled. A 16-bit data word is used for transferring the speed setpoint. The actual speed value is also transferred back from the drive in 16 bits. In SIMOTION, this message frame can only be used for the "speed axis" function.
Standard message frame 2
Is designed for more complex speed-controlled applications. In addition to the control and status word, the speed setpoint is transferred using a 32-bit data word. The actual speed value is also transferred back from the drive in 32 bits. In addition this message frame has a second control and status word which handles the "travel to fixed endstop" functionality (clamping torque must be configured in the drive, is not used in this form by SIMOTION for the "travel to fixed endstop" function). In SIMOTION, this message frame can only be used for the "speed axis" function.
Standard message frame3
Is designed for positioning applications. It also has an encoder control word, an encoder status word and a 4-word interface to a measuring system. SIMOTION functions, such as reference point approach and measuring input, can be implemented via this encoder control word. In SIMOTION, this message frame can be used for the "positioning axis" function.
SITRAIN Training for
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Page 7
MC-SMO-SYS Axes and Drives in SIMOTION
Structure of Standard Message Frames (2) PSD number Setpoint
1 CW 1
2 3 NSET_B
4 CW 2
5 Enc1_CW
PSD number Actual value
1 STW 1
2 3 NACT_B
4 STW 2
5 Enc1_STW
6
7
8
9
XERR
KPC
6 7 Enc1_XACT 1
8 9 Enc1_XACT 2
Standard message frame 5 (32 bit nset, with 1 encoder + DSC) PSD number Setpoint
1 CW 1
2 3 NSET_B
4 CW 2
5 E1_CW
PSD number Actual value
1 STW 1
2 3 NACT_B
4 STW 2
5 E1_STW
6 7 E1_XACT 1
8 9 E1_XACT 2
. . .
10 E2_STW
11 12 E2_XACT 1
13 14 E2_XACT 2
Standard message frame 6 (32 bit nset, with 2 encoders + DSC)
6 E2_CW
PSD number Setpoint
1 CW 1
2 3 NSET_B
4 CW 2
5 MOMRW
6 E1_CW
PSD number Actual value
1 STW 1
2 3 NACT_B
4 STW 2
5 MSGW
6 E1_STW
7
8
9
XERR
7
10 KPC
8
. . .
9
10
XERR
KPC
7 8 E1_XACT 1
9 10 E1_XACT 2
SIEMENS message frame 105 (32 bit nset, with 1 encoder + DSC + torque reduction)
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.8
SITRAIN Training for Automation and Drive Technology
Standard message frame 4
This message frame is designed for connecting a second encoder. It is used in SIMOTION for coupling positioning axes with a 2nd measuring system.
Standard message frame 5
Is intended, just like standard message frame 3 for positioning applications. However, it has two additional double words in the setpoint for transferring the following error and the servo gain (KPC gain). In SIMOTION, this extension is required for the DSC functionality (dynamic servo control). When this function is selected, the dynamic part of the position controller is transferred from SIMOTION to the drive and calculated with the sampling frequency of the speed controller. As part of this process, the following error (XERR) and servo gain KPC are transferred from SIMOTION to the drive. Due to the higher sampling frequency in the drive, the position control can now be operated with a higher servo gain.
Standard message frame 6
Like standard message frame 4 with DSC, or standard message frame 5 with a 2nd encoder. This is used in SIMOTION for coupling positioning axes with a 2nd measuring system.
SIEMENS message frame 102 . . . 106
SIEMENS message frames 102 to 106 are created from the associated standard message frames 2 to 6 by inserting an additional word in the setpoint (after control word STW2) or a word in the actual value (after status word ZSW2). This extension is required for the dynamic torque reduction at the drive. The torque limit is specified in the setpoint; in the actual value the drive among others returns whether the torque limit (current limit) was reached or not. This extension is used in SIMOTION to implement the functions "Travel with torque limit" and "Travel to fixed endstop".
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MC-SMO-SYS Axes and Drives in SIMOTION
Overview: Drive Coupling ADI4
SINAMICS
Analog drives
S120
PROFIBUS interface
MASTERDRIVE
MICROMASTER/ SINAMICS G120
MC
MM410/420/440
Posmo S/CA/CD
611U
DP standard slave
Isochronous on PROFIBUS DP(DRIVE)
DP cycle clock
1ms, 0.5 ms granular
TO connection
3 ms
Speed-controlled axis, positioning, synchronism, cam
Preferred message frame
Drive configuration
SIMODRIVE
1ms, 0.5 ms granular Speed-controlled axis
3
105
105
5
1
Proprietary
Starter
SimoComU
Drive monitor
Starter
Drive ES
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
Drives on PROFIBUS MC
SITRAIN Training for
09.02.2012 MC-SMO-SYS_05.9
SITRAIN Training for Automation and Drive Technology
The following applies to drives connected to PROFIBUS DP: On an isochronous PROFIBUS MC, only drives can be operated in the isochronous mode that also comply with PROFIDRIVE-profile V4.0. All other drives (standard slaves) can be connected to the isochronous PROFIBUS MC - but not operated in the isochronous mode. The following drives are integrated in the STEP 7 project via the hardware configuration: • SINAMICS S120 • SIMODRIVE 611U • SIMODRIVE POSMO CA • SIMODRIVE POSMO CD • SIMODRIVE POSMO SI • ADI4 • MASTERDRIVE MC • MASTERDRIVE VC • MICROMASTER 420/430/440 • COMBIMASTER 411 MICROMASTER 420/430/440 and SINAMICS S120 can be configured, assigned parameters and commissioned directly with SIMOTION SCOUT.
Automation and drive technology
Page 9
MC-SMO-SYS Axes and Drives in SIMOTION
Technology Objects (TO) in SIMOTION Configuration data Cam System variable
Configuration data
Alarms
System functions
System functions
System variable
SynSystem chronous funcoperation tions
Configuration data
Alarms
Encoder System funcSystem tions variable Alarms
Output cam System variable
Date: File:
Siemens AG 2012. All rights reserved.
Technology objects
SITRAIN Training for
Axis System functions Alarms
Configuration data
Alarms
SIMOTION
Configuration data
System variable
Measuring input System variable
Configuration data
System functions
Alarms
09.02.2012 MC-SMO-SYS_05.10
SITRAIN Training for Automation and Drive Technology
The technology objects in SIMOTION are provided in the form of technology packages that can be loaded. Each of these technology packages provides complete functionality for the technology in question. For instance, the "Position" technology package includes all of the functions, which are required to traverse and position axes. In SIMOTION, for each "physical" automation object, for example, an axis, an external encoder, a measuring input etc., an appropriate technology object (TO) is created (instantiated). Each TO in SIMOTION encompasses: • Configuration data: Using configuration data, the created objects are adapted to the requirements of the specific task or application. • System data: In the system data, a TO provides information about its present state. The system data of an axis TO will therefore display information such as position setpoint, actual position value, following error etc. Using system variables, standard values and settings can also be read or entered. • System functions: Using system functions, the user program accesses the functionality to control the associated "physical" object. For example, for an axis TO, there are powerful system functions available for positioning, reference point approach, stopping etc. of an axis. For example, the motion sequences of an axis are specified using motion commands issued to that axis. The user program can be used to query the motion status at any time and to control specific aspects of the motion. Motions can be aborted, overridden, appended, or superimposed. • Alarms:If an event (error, note) occurs on a technology object, the TO issues a technological alarm. The TO alarms cause subsequent responses in the system. For each alarm, certain effects are set as default. However, these settings can be adapted to the specific requirements.
Automation and drive technology
Page 10
MC-SMO-SYS Axes and Drives in SIMOTION
The "Axis" Technology Object
4 versions
• Motion with speed setpoint • Specification of a velocity profile (time-controlled) • Traversing with torque limiting
Synchronous axis Positioning axis
Path interpolation axis
Synchronous axis •
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
SITRAIN Training for
Positioning axis • Positioning via • Positioning command or via profile input (velocity, position) • Traversing to a fixed endstop
Speedcontrolled axis
Axis TO
Speed-controlled axis
Following axis in gearing or camming operation
Path axis •
Linear, circular and polynomial interpolation in 2D and/or 3D
•
support of various kinematics
09.02.2012 MC-SMO-SYS_05.11
SITRAIN Training for Automation and Drive Technology
The axis motion control functionality is implemented in SIMOTION using the technology object (TO) axis. When creating an axis with SIMOTION SCOUT, a distinction is made between the following axis technologies: • Speed-controlled axis: Motion control is performed using a speed setpoint without position control. The actual speed is monitored if an encoder is configured for the axis. • Positioning axis: Motion control for position-controlled axes. The position as well as the dynamics of the axis are specified. The operation is realized in the closed-loop position controlled mode. The functionality of the speedcontrolled axis is included in the positioning axis. The positioning axis in SIMOTION has a position controller. With electrical axes, the speed controller is implemented in the drive. • Synchronous axis: The functionality is identical with that of a positioning axis. In addition, additional functions are available for the master value coupling in the form of gearing and camming • Path axis: From Version V4.1, SIMOTION provides path interpolation functionality. This functionality encompasses that of the positioning axis. Additionally up to 3 path axes can be traversed along paths. In addition, a position axis can be traversed synchronously with the path. Paths can be combined from segments with linear, circular, and polynomial interpolation in 2D and 3D. Further, using this technology, the following kinematics are supported: - Cartesian linear aches - SCARA - Roller picker - Delta 2D /3 D picker - Articulated arm The "Axis" technology object can be used for axes with electric drives, with stepping motors, hydraulic actuators/valve (hydraulic axis) and on virtual axes.
Automation and drive technology
Page 11
MC-SMO-SYS Axes and Drives in SIMOTION
Creating and Configuring an Axis
Using parameter screens
Using expert list
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
Configuration of TOs
SITRAIN Training for
09.02.2012 MC-SMO-SYS_05.12
SITRAIN Training for Automation and Drive Technology
You will need to work through several steps before you can use technology objects. In the first step, the configuration creates an instance of the TO. A TO is configured using the SCOUT engineering system. You are supported by the corresponding Wizards (parameterizing screen forms) to create an object and configure it. Inserting an axis instance is implemented in the Project Navigator in the directory Axes, by double-clicking on the entry "Insert axis". The axis wizard then automatically starts and helps the user create and configure an axis. Certain object-specific properties are determined in the first configuration (e.g. speed-controlled axis, positioning axis, synchronized axis). This definition also determines the "size", i.e. the number of configuration and system variables of the technology object. It is therefore not possible to subsequently change properties such as speedcontrolled axis, positioning axis, etc. If a speed-controlled axis TO is to be converted into a positioning TO, it is necessary to delete the original speedcontrolled TO and insert a new positioning axis TO. Configuration data generally determines the static properties of a TO. Certain properties determined by the configuration can also be changed during the runtime.
Automation and drive technology
Page 12
MC-SMO-SYS Axes and Drives in SIMOTION
The Basic Configuration of an Axis Configuration
Name and technology of the axis
Associated drive
Associated encoder
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
Basic configuration
SITRAIN Training for
09.02.2012 MC-SMO-SYS_05.13
SITRAIN Training for Automation and Drive Technology
The basic properties of the axis are defined in the basic configuration of an axis. The following settings can be adapted in this basic configuration. Technology/processing cycle: The execution level for axis interpolation is defined in this selection box. The following can be selected: • IPO for dynamic axes • IPO2 for auxiliary axes which have low dynamic requirements • Servo for axes demanding a high dynamic performance From V4.2 and higher, for axes connected to PROFINET (these are generally hydraulic axes) the following level is also available: • fast IPO • fast servo Axis type: Under this dialog, axis type changes can be made (linear or rotary and electrical, hydraulic or virtual). In addition, control options can be adapted, for example, standard or standard + pressure/force. Drive assignment: Under drive assignment, the connection to the associated drive object can be changed. Function: This part involves settings to an additional technology data block in the message frame between the TO axis and drive object A technology data block is required for the "Winder" technology. Further, settings can be made to withdraw enable signals for critical TO alarms (refer to the next page). Further, settings can be made for extended safety functions that are integrated in the drive.
Automation and drive technology
Page 13
MC-SMO-SYS Axes and Drives in SIMOTION
Selectively Removing Drive Enable Signals
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.14
SITRAIN Training for Automation and Drive Technology
Settings to the drive
Here, there is the option, for technology alarms with local alarm response RELEASE_DISABLE (withdraw enable), to specifically withdraw the enable signals in STW1 of the corresponding standard message frame. This means, for example, when implementing a brake control in the drive, for _disableAxis() as well as for RELEASE_DISABLE as a result of a fault response, e.g. initially to withdraw OFF3 (STW1.Bit2), and then when the drive is stationary and the brake is closed, the power is disconnected (OFF2) (STW1.Bit1). Also when using the extended Safety Integrated function, an adaptation is absolutely necessary at the drive. For an integrated stop response of the drive, withdrawing the AUS2 bit must be prevented, as otherwise the drive will coast down in an uncontrolled fashion.
Stop modes for PROFIdrive
For a digital drive coupling, the Drive Technology profile provides the following stop modes: • STW1 bit 0 = 0 (OFF1): Stop with ramp. The drive travels with a speed ramp with adjustable deceleration to zero velocity. The stopping process can be interrupted and the drive switched on again. After stopping, the pulses are suppressed and the status changes to ready to start. • STW1 bit 1 = 0 (OFF2): Coast down The drive immediately goes to pulse suppression and the status changes to switch-on inhibit. • STW1 bit 2 = 0: Quick stop The drive travels to zero velocity at the torque limit. The stopping process cannot be interrupted. After stopping, the pulses are suppressed and the status changes to switch-on inhibit.
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Page 14
MC-SMO-SYS Axes and Drives in SIMOTION
Calling the Expert List
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.15
SITRAIN Training for Automation and Drive Technology
General
After the configuration the next step is to set the parameters for the technology object. Parameterization involves defining numerous functions in detail. Like the configuration, parameterization is carried out using the SCOUT engineering system. Below the object in the project navigator window, there are the appropriate entries, via which the individual screen forms can be called for parameterization (making the appropriate parameter settings). The result of the parameter assignment is stored in configuration data and system variables for the object and included in the download to the target system.
Expert List
In addition to access to the configuration data and system variables via the wizards and parameter screen forms, you can also access the data directly via an expert list. The expert list for an object can be called via the entry "Expert list" of the axis TO. Within the "Expert list", lists for the following parameters can be selected using the tab symbol: • Configuration data: Configuration data are used to parameterize the properties of a machine. As a consequence, mechanical properties, for example, gearbox ratios, hardware limit switches, maximum dynamic values, closed-loop control parameters, etc. are defined. • System variables: System variables are generally used to display status information about the selected TO. For axes, this involves positions, velocities etc. From the user perspective, such data can only be read. Using system variables that can be written to, a basic parameterizing interface to the TO is also implemented. These include, for example, velocity override, preassigned values (default values) of velocity, acceleration etc. for traversing commands • User-defined lists: From V4.0 and higher, there are user-defined expert lists and the option of calling default lists with the most important configuration data and system variables.
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Page 15
MC-SMO-SYS Axes and Drives in SIMOTION
Specifying Mechanical Data
Load gear: transmission ratio
Measuring gear: transmission ratio
Automatically adapted; if TypeOfAxis.DriveControlConfig.dataAdaption = YES TypeOfAxis.NumberOfEncoders.Encoder_1.dataAdaption = YES TypeOfAxis.NumberOfEncoders.Encoder_1.encoderMode = PROFIDRIVE
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.16
SITRAIN Training for Automation and Drive Technology
General
After the configuration the next step is to set the parameters for the technology object. Parameterization involves defining numerous functions in detail. Like the configuration, parameterization is carried out using the SCOUT engineering system. Below the object in the project navigator window, is a row of tabs for displaying the individual screens for parameter settings. The result of the parameter assignment is stored in configuration data and system variables for the object and included in the download to the target system.
Mechanical Properties
When controlling a drive by means of the "Axis" technology object, SIMOTION uses only the speed setpoint interface and not the positioning interface. The drive therefore has no information about traversing paths, etc. All mechanical data regarding lengths, leadscrew pitch, etc., must be defined in SIMOTION.
Automatic adaptation
Using automatic adaptation, from V4.2 SP1, the relevant drive data (drive and encoder data, as well as reference variables, maximum variables, torque limits, and the selectivity associated with torque reduction of the SINAMICS S120 from v2.6.2) are transferred into the TO configuration when the CPU boots and do not have to be manually set. For a "Copy current data to RAM" or "Copy RAM to ROM", in a dialog, it is possible to load the adapted values to the PG and therefore into the offline project. If required, the adaptation can be activated in the expert list using the following Config data: • TypeOfAxis.DriveControlConfig.dataAdaption = YES • TypeOfAxis.NumberOfEncoders.Encoder_1.dataAdaption = YES • TypeOfAxis.NumberOfEncoders.Encoder_1.encoderMode = PROFIDRIVE
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MC-SMO-SYS Axes and Drives in SIMOTION
Parameterizing Default Settings
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.17
SITRAIN Training for Automation and Drive Technology
Default value for Dynamic response
The system always uses the default values if, when calling the system functions, USER_DEFAULT is specified. This means that the dynamic values for each axis can be defined centrally just once and do not have to be re-entered whenever the system function is called. The following dynamic variables of an axis can be assigned as default values in this dialog • Velocity • Acceleration • Deceleration • Jerk • Velocity profile • Stopping time
Stopping Time
The time specified under Stopping time applies if a moving axis is stopped via "Emergency stop in pre-defined time", for example.
Velocity profile
The velocity profile defines the axis response during approach, braking, and velocity changes. You can choose between the following profiles: • Trapezoidal: The trapezoidal profile is used for linear acceleration in a positive and negative direction of travel. • Smooth: The profile displays a smooth acceleration character and the jerk characteristic is controllable.
Presetting the dynamic response
Depending on the settings for maximum dynamic response, dynamic response values can be preset as default values in the system. You specify the settings regarding maximum dynamic response using "Maximum velocity" and "Rampup/acceleration time up to maximum velocity".
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MC-SMO-SYS Axes and Drives in SIMOTION
Specifying Limit Switches and Maximum Velocities Assign
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.18
SITRAIN Training for Automation and Drive Technology
Hardware limit switches
Traversing range limits are monitored by means of digital inputs and limit switches. Hardware limit switches are always NC contacts and should always be active outside the permissible travel range. When a limit switch is approached, a technology alarm is triggered. The logical address of the input which the hardware limit switch for negative/ positive direction of travel is connected to is entered in "Hardware limit switch". The address must be outside the process image (>= 64). With the bit number, the input is specified to which the hardware limit switch for negative/positive direction of travel is connected. From V4.2 and higher, the inputs for the hardware limit switches can also be easily connected with the inputs of the CU of SINAMICS_Integrated. By clicking on the "…" button, the assignment dialog is opened, in which the interconnection with the CU inputs can be made. "Save and compile" is used to create the necessary message frames between the CU and SIMOTION.
Software limit switches
Software limit switches can be specified and activated. They are activated via system variables (Swlimit.State). You can also specify in the "Homing" tab in the configuration data: Homing.referencingNecessary whether the software limit switch is always active, or only after referencing/homing: Homing.referencingNecessary = NO software limit switch always active Homing.referencingNecessary = YES switch active after referencing/homing
Maximum velocities
In SIMOTION there are two velocity limits. SIMOTION automatically reduces to the minimum of the two values Maximum velocity (configuration data): Defines the maximum axis velocity as a result of the mechanical system and the drive. Maximum programmed velocity (system variable): Permits a product-dependent reduction of the maximum velocity.
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MC-SMO-SYS Axes and Drives in SIMOTION
Specifying the Maximum Acceleration and Jerk
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.19
SITRAIN Training for Automation and Drive Technology
Acceleration, jerk
SIMOTION makes a distinction for acceleration and jerk between hardware limits in configuration data and software limits in system variables, which, for example depending on the product, can be easily overwritten from the user program. For programmed motion, the TO automatically reduces the acceleration and/or the jerk to the minimum from the limits specified by the hardware and/or software. Jerk limiting is only active for jerk-controlled motion, i.e. motion sequences with continuous acceleration. If the "Direction dependent dynamic response" option is activated, then different limits for acceleration and jerk can be entered depending on the direction of motion.
Stopping with pre-parameterized braking ramp
The set value is effective, if a moving axis is stopped in the "EMERGENCY OFF mode" with the setting "Quick stop with actual value-related emergency stop ramp".
Time constant ...
From V4.0 and higher, a time constant can be entered for smoothing the manipulated variable changes as a result of controller switching operations. This switchover smoothing filter is active for all status transitions/switchovers in which an offset in the manipulated variable can occur due to the switchover. Gearbox change operations in the data block are not smoothed
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MC-SMO-SYS Axes and Drives in SIMOTION
Filtering the Actual Value for Master Value Coupling
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.20
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Master value coupling via actual value
For a synchronous group within a control system, synchronous operation is realized taking into account the master value position, the velocity and acceleration. For distributed synchronous operation, the master value position and master value velocity are transferred between the master value and synchronous object. At the synchronous object, acceleration is generated through differentiation If an encoder actual value is used as master value, then the measured actual value can be smoothed and extrapolated in order to compensate deadtimes. Deadtimes, occur when acquiring the actual values through bus communication in the system and as result of the finite processing duration within the system.
Filtering the actual position
From V 4.1, the actual position value for the synchronous operation can be filtered separately for the extrapolation using a PT2 filter. The filter for the position actual value of the axes is set using the option "Filter on the actual position value" and the two time constants "T1" and "T2". The filter acts on the actual position for the extrapolation before the differentiation of the position for the extrapolation velocity.
Filtering the actual velocity
The position is extrapolated based on the filtered or averaged velocity actual value. This filter can be activated using the option "Filter on the actual velocity value": The time for the average value generation or the PT1 filter time is entered under "Time constant. The time for the extrapolation is entered under "Extrapolation time". Extrapolation is not performed if 0.0 is entered. The extrapolated values (position and velocity) can be monitored in the system variable extrapolationData.... In addition, the velocity master value can be optionally generated from the extrapolated position master value through differentiation or the extrapolated velocity master value can be used for synchronous operation.
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MC-SMO-SYS Axes and Drives in SIMOTION
Position Control in SIMOTION
DSC operation Servo gain factor
IPO
Feedforward control
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.21
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Interpolator
The interpolator processes the traversing commands which are issued e.g. from the user program to an axis. In each IPO cycle it calculates the position setpoint of the axis while including the dynamic values such as acceleration, velocity etc. in its calculation. This position setpoint is then entered into the position controller after fine interpolation.
Fine interpolation
If there is a different sampling ratio between interpolator and position controller, the fine interpolator (FIPO)'s task is to generate intermediary setpoints. For the configuration you can select in the "Fine interpolation" box between no, linear and constant speed interpolation.
Position control
The position controller is responsible for controlling the actual position of the axis. It is usually designed as P controller for electrical axes. The difference between the position setpoint and position actual value is used as the control deviation value (following error). Multiplied with the servo gain factor, the result – the velocity setpoint of the axis – is output at the position controller output. The dynamic response and therefore the rise time in the position control loop is determined in this case by the servo gain factor (or more precisely: 1/sg = rise time). The maximum possible servo gain depends on the dynamic properties of the drive (e.g. rise time, etc.) and mechanical properties of the axis (moment of inertia, backlash, etc.) as well as on the set position control cycle (sampling theorem).
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MC-SMO-SYS Axes and Drives in SIMOTION
Position Controller Optimization without Precontrol Unoptimized position control
Velocity setpoint: motionstatedata.commandvelocity Actual velocity: motionstatedata.actualvelocity
Optimized position control
Servo gain factor
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
Optimizing the position controller
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Prerequisite for optimizing the position controller is that the current and speed controller have already been optimized for the drive. Then the setpoint and actual velocity of the axis can be optimized for the position controllers using trace recording. The axis can be moved via an MCC program or via the function generator of the trace tool. The axis should accelerate, alternating between positive and negative velocity. The axis acceleration should be selected so that the current limit is not reached. The position control can then be optimized by increasing the servo gain factor. Good optimization of the servo gain was achieved if the actual velocity follows the specified setpoint velocity during axis acceleration without any overshoot. In this case the setpoint and actual velocity/actual velocity and following error of axis can be recorded in the trace tool via the following system variables: • .motionstatedata.commandvelocity • .motionstatedata.actualvelocity • .positioningstate.differencecommandtoactual These system values are determined in the interpolation. In particular, this means that all values which refer to the actual position/velocity are outdated compared to the associated values of the position control.
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MC-SMO-SYS Axes and Drives in SIMOTION
Position Control with Precontrol servoData.compensatedServoCommandValue
Velocity setpoint
Interpolator
Position setpoint
Feedforward control
* KPC balancing filter
SA
-
* KV
+
nset
servoData.controllerOutput servoData.followingerror
Expert mode
servoData.preControlValue
Symmetrization time constant
servoData.controllerDifference servoData.symmetricServoCommandVelocity servoData.symmetricServoCommandPosition
O
sensorData.sensorData[1].actual velocity sensorData.sensorData[1].position
Act. position val. Dead time (transfer on PROFIBUS, rise time, ...)
Configurationdata.TypeOfAxis.NumberOfDataSets.DataSet_1.DynamicData.velocityTimeConstant = vTc (velocityTimeConstant)
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.23
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Precontrol
The conventional position control concept (P controller) always requires a deviation (following error = FE) between position setpoint and actual position value. This deviation can lead to unwanted axis behavior, e.g. contour errors, poor dynamics (performance characteristics during rise time) etc. The task of the precontrol is to compensate these disadvantages. The precontrol calculates the axis (setpoint) velocity directly from the position setpoints by differentiation, multiplies it with the KPC factor, then transfers it directly to the position controller output. In the best case, the precontrol setpoint will cause the axis to move at the velocity calculated by the interpolator. If the actual axis position was immediately returned to the position controller, then the following error would be 0. The position controller would then only have to deal with the task of correcting disturbance-induced fluctuations of the real actual axis position with respect to the position setpoint.
Delay times
Unfortunately, data processing and transfer as well as the rise time of the drive lead to delay times which have a considerable negative impact on the conventional position control concept with precontrol. There is a time lapse which cannot be neglected between supplying the position setpoint to the following error and returning the first actual position values to the position control. This delay time is mainly as a result of: • The dead times for transferring the setpoint/act. value (2xDPcycles + Ti + To) • Equivalent time for the speed control loop of the drive (approx. 1-5 ms). If this time delay would not be compensated in one form or another, then the speed setpoint output to the drive when the axis starts would be too high. This excessive speed setpoint would result in overshoot and/or unstable performance characteristics during drive rise time. The increased speed setpoint is a result of the speed setpoint of the precontrol and a component originating from the position setpoint supplied to the following error. The actual value "missing" at the beginning of the motion will inevitably result in an increase of the following error and therefore output of an additional speed setpoint.
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MC-SMO-SYS Axes and Drives in SIMOTION
Selecting a Suitable Balancing Filter Type Selection in the input field "Balancing filter" "Extended balancing filter active"
or via expert list (configuration data): TypeOfAxis.NumberOfDataSets.DataSet_1.ControllerStruct. PVController.balancedFilterMode
nact PT1- filter Mode_1
Command value Actual value
+
time
time nact
Extended balancing filter
Command value
Actual value Mode_2
SIMOTION
time Date: File:
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09.02.2012 MC-SMO-SYS_05.24
time SITRAIN Training for Automation and Drive Technology
Balancing time vTc
Delay in returning the actual position value output compared to input of the position setpoint in the following error and resulting undesirable increase in the output speed setpoint which can be compensated by means of delayed input of the position setpoint to the following error. The delay (balancing time vTc) of the input of the position setpoint to the following error should exactly compensate for the delay in the return of the actual position. This is the approximately the case if the balancing time vTc is set to the same value as the calculated delay time Tequiv.
Filter mode
In the first version of SIMOTION, a pure PT1 filter was used This type has the disadvantage, that when accelerating, the delayed setpoints at the output do not match the characteristics of the actual values returned from the encoder. In the initial phase of the acceleration, a PT1 filter already supplies setpoints; however there are still no actual values from the encoder as a result of the deadtime in the position control loop. As a consequence, there is a small positive following error at the output, and therefore an additional and positive value added to the speed setpoint that is output. Vice versa, in the final acceleration phase, the actual values of the encoder system have already been fed back into the position control, while the PT1 filter is still delaying the setpoints that are applied. As a consequence, in the final phase, there is a negative contribution added to the following error, and therefore a negative contribution added to the speed setpoint that is output. The result is generally an overshoot or undershoot of the speed setpoint that is output, and therefore the velocity actual value that cannot be resolved through optimization.
Expanded balancing filter
In SIMOTION, an additional filter was integrated, which better matches the characteristics of the actual values returned from the encoder system. Using this filter (expanded balancing filter or Mode_2) the undesirable undershoot or overshoot issue can, to a large extent, be avoided.
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MC-SMO-SYS Axes and Drives in SIMOTION
Optimizing the Balancing Time Constant (vTc) motionstatedata.commandvelocity
KV = 80/s vTc = 7.5 ms Without DSC
sensorData.sensorData[1].actual velocity servoData.symmetricServoCommandVelocity motionstatedata.actualvelocity
vTc optimum
KV = 80/s vTc = 1 ms Without DSC vTc too small
sensorData.sensorData[1].actual velocity servoData.symmetricServoCommandVelocity
KV = 80/s vTc = 25 ms Without DSC
vTc too large
SIMOTION
Date: File:
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09.02.2012 MC-SMO-SYS_05.25
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Continuation
The filter can be activated using the following configuration data in the expert list: • .NumberOfDataSets.DataSet[1].ControllerStruct.PV_Controller. balanceFilterMode = Mode_2 With "Mode_2", a dead time + PT1 filter is used, while Mode_1 uses a pure PT1 filter.
Type of fine Interpolation
For selecting the precontrol, constant velocity fine interpolation must also be selected. The type of fine interpolation is set in the dialog "Axis -> Fine interpolation" in the "Fine interpolator" selection field: • "Fine interpolator = constant velocity interpolation" If "No interpolation" or "Linear interpolation" would be selected, undesired speed jumps would take place at the drive in the acceleration phase of the axis.
Determining the start values for vTc
Then, the start values for the balancing filter time can be determined. These times essentially depend on whether DSC operation has been selected or not: • without DSC operation: vTc = 2 x DP cycle time + Ti +To + rise time of the drive • with DSC operation: vTc = rise time of the drive (equivalent time of the speed control loop)
Optimizing vTc
Then you can proceed to optimize the servo gain Kv for the axis in the usual manner. However, if an optimum rise time behavior is not achieved, then this must be compensated by modifying vTc. • Axis not dynamic enough: In this case, vTc must be reduced. Selecting vTc to be equal to Tequiv is only a first approximation. • Axis overshoots: In this case, vTc must be increased.
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MC-SMO-SYS Axes and Drives in SIMOTION
Position Control with DSC – the PROFIdrive DSC Structure n set nset (precontrol)
Position calculation (interpolator) xset
xDiff
Speed filter
Deceleration Fine interpolation Position (1 DP cycle) controller
ndrive
xact,SIMOTION
Speed controller
Speed calculation
3 2
1
Xact,SIMOTION
Tpc
xact, drive Tpc
Tsc xact,motor
Zero offset and compensations
SIMOTION
Speed controller cycle 125 us
Position controller cycle 1-2 ms
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
09.02.2012 MC-SMO-SYS_05.26
Drive
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Dynamic Servo Control (DSC)
With the "Dynamic Servo Control" function, the dynamically active part of the position controller is transferred to the drive and performed using the sampling time of the speed control loop. This allows a higher servo gain factor and consequently greater dynamic response in the position control loop. Better dynamic performance is achieved both for the command variable and for eliminating disturbances. The structure of the DSC contains 3 branches for the feedback of the actual position (nos. 1, 2 and 3). The feedback no.2 totally compensates the actual value Xact, which is transferred from SIMOTION to the drive (no. 1). Therefore the only relevant feedback of the actual position is branch no. 3. The DSC structure allows a dynamic switchover between conventional position control and operation with DSC. All monitoring functions as well as knowledge about the actual position (reference point) must be - independent of DSC implemented only in SIMOTION.
SIMODRIVE 611 U MASTERDRIVES SINAMICS S120
DSC is supported by MASTERDRIVES (standard message frames 5 and 6 PROFIdrive) and SIMODRIVE 611U or SINAMICS S120 (in addition, message frames 105 and 106). Scripts on the AddOn - CD (4_Accessories\Masterdrives\Scripts) are available to support commissioning of MASTERDRIVES.
Compensations
The DSC function is not only used in the SIMOTION system, but also in all of the SIEMENS motion control systems, for example SINUMERIK. The SINUMERIK system uses, in the actual value branch, a wide range of compensations, for example spindle pitch error, sag compensation etc. This means that in the position control loop of SINUMERIK, actual values from the drive are not directly input, but an actual value that is compensated according to tables. The DSC function has now been designed, so that these compensations can be kept in their original form. Precisely, branch number 2 only compensates the noncompensated actual value in the following error, i.e. the compensation "survives".
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MC-SMO-SYS Axes and Drives in SIMOTION
Position Controller Optimization with Precontrol and DSC Settings: •
Activate precontrol,
•
Weighting factor: KPC = 100
•
Activate DSC operation
• •
Activate expanded balancing filter (FilterMode = Mode_2) Balancing time vTc = equivalent time of the speed control loop
motionstatedata.commandvelocity
servoData. precontrolvalue sensorData.sensorData[1].actual velocity servoData.symmetricServoCommandVelocity
KV = 200/s vTc = 2.5 ms with DSC
motionstatedata.actualvelocity
SIMOTION
Date: File:
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09.02.2012 MC-SMO-SYS_05.27
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Start value for VTc with DSC operation
Using DSC and precontrol, it is only necessary to take into account the equivalent time constant of the lower-level speed control loop. In this case, delay times resulting from data processing or transfer are not included in the balancing time constant. • vTc = rise time of the drive (equivalent time of the speed control loop)
Optimizing vTc
The optimum performance characteristics during rise time can be achieved by changing vTc. vTc is set to the optimum value if the actual velocity of the axis (.servodata.actualvelocity) follows the "delayed" setpoint velocity (.servodata.symmetricservocommandvelocity) by approx. 2 DP cycles. The servo gain Kv can then be optimized in the usual manner.
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MC-SMO-SYS Axes and Drives in SIMOTION
Dynamic Adaptation for Synchronous Axes servoData.compensatedServoCommandValue
Precontrol
servoData.TotalServoCommandValue
Interpolator
* KPC
Dynamic adaptation T1, T2 and deadtime
Sym. filter
-
SA
* KV
+
n set
Dead time
A
Position actual value Dead time Configuration data.TypeOfAxis.NumberOfDataSets.DataSet_1.DynamicComp.enable = activation Configuration data.TypeOfAxis.NumberOfDataSets.DataSet_1.DynamicComp.T1 = time constant T1 Configuration data.TypeOfAxis.NumberOfDataSets.DataSet_1.DynamicComp.T2 = time constant T2 Configuration data.TypeOfAxis.NumberOfDataSets.DataSet_1.DynamicComp.deadTime = dead time
SIMOTION
Date: File:
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09.02.2012 MC-SMO-SYS_05.28
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Dynamic adaptation for synchronous axes
If, for the position controller optimization of axes, that will be subsequently operated in a synchronous group, different time constants were set, then the resulting time difference must be compensated; if this is not done, then the actual axis contours will differ in synchronous operation. These different time constants can be caused by: • different balancing times vTc for 100% precontrol • different servo gain factors without precontrol In the first case, the position difference is a sequence of different time delays when entering the position setpoints into the position control. For example, the position actual value of an axis in the constant velocity phase would always be obtained so that in the position controller the resulting system deviation is equal to 0, i.e. the delayed position setpoint fed in minus the position actual value. In a second case, the difference is caused by different servo gain factors. Thus, for example in the constant velocity phase, the actual position of the axis always moves a time 1/Kv = TLR after the position setpoint. Further, it must always be observed, that either all axes are traversed in the synchronous group with DSC or without DSC.
T1, T2, TRes
As a result of the dynamic adaptation, a delay is created in the position setpoint of the axis. The delay is caused by two PT1 elements and a resulting dead time. Using the configuration data: TypeOfAxis.NumberOfDataSets.DataSet_1.DynamicComp.enable the dynamic adaptation can either be activated or deactivated. As resulting total time constant TRes the equivalent time constant of the axis with the poorest dynamic performance is selected. T1, T2 and/or the dead time must then be set, so that the resulting equivalent time TRes is identical for all axes in the synchronous group, i.e.: • TRes = T1 + T2 + dead time + vTc (1st case) • TRes = T1 + T2 + dead time + TLR (2nd case)
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MC-SMO-SYS Axes and Drives in SIMOTION
Checking the Dynamic Adaptation Using the Circularity Test Programmed radius
"good" dynamic response adaptation
"Actual" radius
SIMOTION
Date: File:
Siemens AG 2012. All rights reserved.
Circularity test
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"Poor" dynamic response adaptation
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From V4.0, the SIMOTION trace tool also includes a circularity test. For a circularity test, two axes are traversed along a circular path and the actual path is compared with the program path. This allows the dynamic response and the synchronous operating behavior of the axes to be tested. Essentially, the circularity test can be executed in the two following configurations: • The two axes interpolating with one another are real positioning axes: The deviation between the programmed and actual radius provides a measure of the following error (pythagoras). A deviation from a pure circular shape (rotated ellipse) indicates different following errors of the two axes when interpolating and therefore a poor dynamic response adaptation. A good dynamic performance adaptation has been achieved, if the actual path keeps its circular shape. • One of the axes is a real positioning axes, the other axis is a virtual axis. In this particular case, the dynamic response of the real positioning axes is tested. The best setting is achieved, if the resulting path is a circle where the programmed radius is the same as the actual radius. This can only be achieved, if the axis precisely traverses without any following error even in the acceleration phase.
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MC-SMO-SYS Axes and Drives in SIMOTION
Positioning and Standstill Monitoring
servoMonitoring.positioningState • ACTUAL_VALUE_OUT_OF_POSITIONING_WINDOW • ACTUAL_VALUE_INSIDE_POSITIONING_WINDOW • STANDSTILL_MONITORING_ACTIVE
SIMOTION
Date: File:
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09.02.2012 MC-SMO-SYS_05.30
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Positioning monitoring
At the end of the positioning movement the movement of the axis into the pre-defined position is monitored on the basis of a positioning window. A positioning window and a time interval are used for this purpose. At the end of position setpoint interpolation, a timer is started with the runtime specified in "Positioning tolerance time". After the timer has expired, the actual position value and the setpoint position value are compared. If the deviation is greater than the value specified in the tolerance window "Positioning tolerance window", then fault message "Fault 50106: position monitoring" is output.
Standstill monitoring
Standstill monitoring monitors the actual position of the axis at the end of a traversing movement. Two time windows and a tolerance window are provided for standstill monitoring. At the end of position setpoint interpolation, if the actual position of the axis has reached the tolerance window for position monitoring, a timer is started with the "Minimum dwell time" runtime. After the time has expired, the standstill monitoring is active and the motion is considered as having been completed (MOTION_DONE). Now, the position actual value is compared with the setpoint position. If the actual position leaves the "standstill window" for longer than the time specified in "Tolerance time", then the error message: "Alarm 50107: Standstill monitoring" is output. If the time intervals for "Minimum dwell time" and "Tolerance time" are equal to 0, the tolerance position window for standstill monitoring must be greater than or equal to the tolerance window for position monitoring.
Note
From V4.1 and higher, in the system variables servoMonitoring.positioningState the status of the axis position is displayed during positioning: • INACTIVE (motion is active) • ACTUAL_VALUE_OUT_OF_POSITIONING_WINDOW • ACTUAL_VALUE_INSIDE_POSITIONING_WINDOW • STANDSTILL_MONITORING_ACTIVE
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MC-SMO-SYS Axes and Drives in SIMOTION
Open-Loop Speed Controlled Motion - Standstill Signal
SIMOTION
Date: File:
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Standstill signal
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For traversing motion of speed-controlled, positioning and synchronous axes, the standstill signal (motionStateData.stillstandVelocity = ACTIVE) is generated, if the actual velocity is less than a configured velocity threshold for, as a minimum, the duration of the delay time. For an Emergency Stop, below this velocity, motion is stopped with setpoint 0 without an emergency stop ramp. If the command with "Attach" is parameterized, then the transition is realized with the output of the standstill signal.
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MC-SMO-SYS Axes and Drives in SIMOTION
Following Error and Velocity Error Monitoring
Dynamic following error monitoring
Velocity error monitoring
SIMOTION
Date: File:
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09.02.2012 MC-SMO-SYS_05.32
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Dynamic following error monitoring
The task of the following error monitoring is to monitor for changes to the following error in the traversing phase. Particularly noticeable changes occur when e.g. the axis unintentionally moves against an obstacle. The following error monitoring on the position-controlled axis is performed using the calculated following error. The maximum permissible following error is calculated from the setpoint speed and the straight lines parameterized in the dialog box above. If this limit is exceeded, "Error 50102: dynamic following error monitoring window was exceeded" is triggered. With velocities less than the specifiable minimum velocity, a parameterizable constant following error is monitored. If several data sets are configured on the axis, the setting for the following error monitoring must be identical in all data sets.
Velocity error monitoring
The velocity error monitoring monitors for possible deviations between the programmed setpoint and actual velocity. This monitoring function is active for speed-controlled axes or for speed-controlled motion of positioning or synchronous axes. For this monitoring function, an encoder must be connected to the axis and be configured. A PT1 model is emulated to monitor the controlled system. The input of the PT1 element is supplied with the programmed setpoint velocity. The emulated "velocity actual value" is available at the output. The monitoring function is initiated if the deviation between the emulated "velocity actual value" and the actual velocity value is greater than the value that has been entered under "Maximum velocity deviation". The time constant for the PT1 model is set during axis configuration in the configuration data dynamicData.velocityTimeConstant or for hydraulic axes in dynamicQFData.velocityTimeConstant. When the velocity error monitoring response, "Alarm 50101 Window for reference model monitoring exceeded" is output.
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Page 32
MC-SMO-SYS Axes and Drives in SIMOTION
Signal Flow Representation of the Closed-Loop Axis Control
SIMOTION
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Signal flow
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09.02.2012 MC-SMO-SYS_05.33
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The dialogs under the "Signal flow" entry provide a functional view of the closedloop control and the parameters of the SIMOTION TO "Axis". Using the individual screen forms, the path from the setpoint position calculated by the interpolator and the actual position sensed by the encoder system can be tracked via the position control up to the manipulated variable output. The variables prepared in the individual intermediate steps, for example positions, velocities, speed etc., are displayed in the various screen forms. The names of the associated system variables from the expert list are displayed at the cursor tool tip (this is important for trace recordings). Further, the parameter settings (configuration data), relevant for the control, can be directly entered in the screen forms. The functional view of the control in SIMOTION provides: • Identical visualization of the SIMOTION and SINAMICS functionality • A better understanding of the internal functions • Parameterization and online diagnostics in a functional view
Automation and drive technology
Page 33
MC-SMO-SYS Axes and Drives in SIMOTION
Programming Traversing Motion Single-axes commands to traverse axes
Set axis enable
Withdraw axis enable
Positioning to a target position
Start axis speed-controlled
Start axis position-controlled
Stop an axis
Reference an axis
SIMOTION
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Overview
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09.02.2012 MC-SMO-SYS_05.34
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To traverse the axes that have been created, what are known as single-axis commands are available in SCOUT. These commands can be inserted in the MCC chart via the associated toolbar in the MCC editor. The group of single-axis commands especially includes the commands for openloop or closed-loop controlled traversing of axes, as well as commands to enable axes, reference axes etc. The commands to activate and deactivate cams as well as handle external encoders are also included in this group.
Automation and drive technology
Page 34
MC-SMO-SYS Axes and Drives in SIMOTION
Enabling and Disabling Axes
SIMOTION
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09.02.2012 MC-SMO-SYS_05.35
SITRAIN Training for Automation and Drive Technology
Switching axis enables signals
This command switches the enable signals at the axis. The axis goes into the follow-up mode if any of the enable signals are missing. Following enable signals can be switched. Position controller enable: The position controller enable activates position control for the axis. You can query the state of the position control using the system variable .servoMonitorings.controlState. The position controller enable is ignored for speed-controlled axes. Switch drive enable: This checkbox switches the drive enable. You can query the state of the current drive enable for real axes using the the system variable .actorMonitorings.driveState. Switch pulse enable: This checkbox switches the pulse enable in the drive module. You can query the state of the current pulse enable for real axes using the system variable .actorMonitorings.power. The enable signals in STW1 according to the PROFIdrive profile can be individually switched. All of the enable signals must be set for position-controlled drive operation.
Follow-up mode
An axis can be switched into the follow-up mode using this check box. No motion commands are executed in the follow-up mode. For positioning axes, in the follow-up mode, the position control is canceled and the position setpoint tracks the position actual value. After the follow-up mode has been deselected, the axes must be re-referenced.
Traversing mode
The axis can be enabled for position or speed controlled operation via the traversing mode. In the speed-controlled mode, the axis can be traversed if an encoder fails.
Remove axis enable
This command automatically removes the position control enable for the selected axis. In addition you can specify whether the drive enable and pulse enable are to be removed too. In the selection box "Follow-up mode", follow-up mode for the axis can be activated.
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Page 35
MC-SMO-SYS Axes and Drives in SIMOTION
Processing Motion Commands MotionTask 1
Start Axis 1
?
¦
Axis 2
Command buffer
Pos(axis1)
Command buffer
Pos(axis2)
Pos(axis1)
Interpolator
?
Interpolator
Fine interpolator Fine interpolator
End
Position controller
Position controller
SIMOTION
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General
Commands can be issued from all user program tasks of the system. The execution time of a command at the technology object is the only factor that determines whether the command is effective. A technology object does not have a task context, and therefore the priority of the task, which issued the command, has no significance for actually executing the command. If commands are issued from multiple tasks, the user program must ensure a consistent sequence of the processing.
Command buffer
In order that several commands can be issued to an axis TO, every axis has a command buffer. This buffer actually comprises four command group-specific subbuffers, which can buffer a command from the one of the following command groups • Emergency Stop and Stop Continue commands • Enable and disable commands • Sequential traversing motion (motion in the basis coordinate system) • Superimposed traversing motion (motion in the superimposed coordinate system) The interpolator at the axis reads out the command at the command buffer (possibly in the interpolator clock cycle) and processes it. Commands from various command groups are, to a certain extent, processed in parallel by the axis TO.
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Page 36
MC-SMO-SYS Axes and Drives in SIMOTION
Transitional Behavior of Motion Commands Position axis Attach Attach - delete pending command
Substitute
Blending
Transitional behavior Superimpose
SIMOTION
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09.02.2012 MC-SMO-SYS_05.37
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Transitional behavior
If a motion command is issued from a MCC chart and if a traversing motion is already active, you can specify in the "Transition behavior" parameter how to process the issued motion command. • Substitute: The motion specified in the issued command becomes active immediately. The motion command being interpolated is interrupted. If the command buffer contains a command, it is cleared. • Attach and discard existing command: The issued command is entered in the command buffer. If the command buffer contains a command, it is cleared. The active traversing motion (interpolator) is not affected. • Attach: The issued command is entered if the command buffer is empty. If the command buffer already contains a command, the call waits until the command buffer is empty and enters the command. • Blending: (like attach) blending is a particular form of two consecutive positioning movements. Contrary to substitution, the motion in the previous command is traversed at the programmed velocity until the target position is reached, the transition takes place in the target position of the previous movement. The setpoint velocity specified in the command for the respective movement is adhered to at all times. • Superimpose: The issued motion is executed as a superimposed movement. Superimposed movements are independent movements that can cancel each other and can be independently stopped/resumed. The superimposed motion is carried out in a superimposed coordinate system as relative or absolute movement depending on how it was programmed. Analogously, the basic movement is carried out in the basic coordinate system as relative or absolute movement depending on how it was programmed.
TO Alarm
Aborted commands in the interpolator trigger a technological alarm "30002 Command aborted".
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Page 37
MC-SMO-SYS Axes and Drives in SIMOTION
Program Advance for Motion Commands Position axis
Step to next command immediately
Motion start
Acceleration end
Start of decleration phase Setpoint
Delay program execution
Actual
End of the setpoint interpolation
Actual
Motion completed, i.e. position window reached
Setpoint
SIMOTION
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09.02.2012 MC-SMO-SYS_05.38
SITRAIN Training for Automation and Drive Technology
Program advance
To synchronize programmed sequence and command processing in the logical object, using the parameter "one command advance" it can be specified as to when, after the command is issued, the program execution should be continued. In this way, the system can wait until the motion has been partially or completely executed. • Do not wait: If, for a pos command in an MCC chart, the checkbox for the option "Delay program execution" is not selected, only when selecting the transition behavior "Substitute" does the system advance to the next command. If "Attach - delete pending command", "Blending" or "Superimpose" is selected in the transition behavior "Attach", then the system waits until the issued command has been entered in the command buffer. When the option "Wait for program execution" is selected, the following settings are available: • Start motion • End of acceleration • Start of braking phase • End of setpoint interpolation • Motion completed, i.e. position window reached
Notes
• • •
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The full control over the immediate advance after issuing a motion command is only possible using the system function calls in the ST language. Interrogating the state of the command buffer is also only possible with ST calls (system function:_getstateofmotionbuffer(...)). In MCC the command buffer can be cleared using the "Clear command queue" command.
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MC-SMO-SYS Axes and Drives in SIMOTION
Synchronous and Asynchronous Program Execution Task x
POS (axis1,...)
Start of axis positioning;
POS (axis2,...)
Task x: wait e.g. until motion has been completed
Synchronous execution (e.g. for MotionTasks)
Task x
Asynchronous execution (e.g. for BackgroundTask, IPOSynchronousTask, etc.)
POS (axis1,...) POS (axis2,...)
SIMOTION
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09.02.2012 MC-SMO-SYS_05.39
Start of axis positioning; Program changes to the next command, without waiting for positioning to be completed
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Asynchronous processing
For asynchronous execution, program processing and the process sequences are synchronized with one another. After a motion command is issued, then the next command in the program is immediately executed. This type of programming must be taken into account in all cyclic tasks, for example, the BackgroundTask. When issuing a motion command, the monitoring of the task run time is not withdrawn. If a program is generated using motion commands, then in this case, the programmer must ensure that all of the calls issued immediately advance to the next command. In the ST language, this is relatively simple, as each motion command has its own "nextCommand" parameter, which controls the advance to the next command. Using the setting (nextCommand := IMMEDIATELY) it is reliably ensured that the system immediately advances to the next command. In MCC, the immediate advance is only ensured for substituting-type transition behavior.
Note
If a program with motion is generated for a cyclic task, then instead of the motion commands from the toolbar the blocks in conformance with PLC-OPEN, available in the library supplied, should be used. These blocks have been specifically designed for use in cyclic tasks.
Synchronous processing
For synchronous execution, program processing and the sequences of the processes are synchronized with one another in some form. After issuing a motion command, the system waits until a special state has occurred in the process (e.g. position reached, velocity reached, etc.) and only then does the program advance to the next command. This type of program generation is only possible in tasks, which are not subject to any runtime monitoring MotionTasks, UserInterruptTasks, etc. MCC with its diagnostic functions specially supports this type of "eventtriggered" programming. Further, this programming style as a whole has a higher level of performance than cyclic programming, as waiting for "events" does not use up any unnecessary CPU time.
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Page 39
MC-SMO-SYS Axes and Drives in SIMOTION
Dynamic Settings for the Positioning Command Velocity profile
SIMOTION
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09.02.2012 MC-SMO-SYS_05.40
Smooth
Trapezoidal
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Velocity profile
You can select a velocity profile for the programmed axis motion. The velocity profile defines the transitions between the individual motion phases. The following are available: • Smooth: In this case the acceleration and jerk can be specified. • Trapezoidal (default setting): With this velocity profile you can only specify the acceleration. The input fields for the jerk are grayed out. The selectable velocity profiles influence the motion transitions between the start and end of the acceleration phase, between constant velocity and acceleration phase/deceleration phase, and the transitions from start and end of the deceleration phase. In addition to direct input of the velocity profile, you can also select from the following options: • Last programmed: The last programmed command becomes effective with this velocity profile • Default: The velocity profile configured in the "Default" dialog when commissioning becomes effective for the command. You can overwrite the default setting of the velocity profile using the MCC command "Set axis parameter".
Entries for Jerk and acceleration
You can define the jerk and acceleration values via the individual combo boxes. boxes. In addition to the two options – "Last programmed" and "Default" – freely editable values or variables can be directly entered or as expression (formula). You can use drag and drop to copy variables from the symbol browser to the input field or copy commands and functions from the command library to the input field. In the selection list you can select whether the programmed jerk or the acceleration should be effective in the configured unit or as a % referred to the standard value.
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Page 40
MC-SMO-SYS Axes and Drives in SIMOTION
Start Axis, Position Contolled or Speed Controlled
Time
SIMOTION
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09.02.2012 MC-SMO-SYS_05.41
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Start axis position controlled
Using this command, positioned controlled traversing of an axis started. A velocity is entered. The axis traverses in this motion, until it is replaced by another motion or is stopped. Time limiting is possible as an alternative.
Time duration
Under the "Dynamics" tab, the checkbox can be activated to parameterize a duration. A time can be entered in the "Time" entry field. The time refers to the start of the constant velocity phase up to the start of the deceleration phase. If no time is specified, then the axis moves until it receives a new command.
Speed input
An axis is traversed, speed controlled, with this command. A setpoint is entered to which the axis can be ramped up via a velocity profile. Also in this case, a time can be entered just the same as for the "Start axis position-controlled" command. If no time is specified, then the axis moves until it receives a new command.
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Page 41
MC-SMO-SYS Axes and Drives in SIMOTION
Stop Axis
Stop mode
Selection
SIMOTION
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09.02.2012 MC-SMO-SYS_05.42
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Stop Axis
The command stops the axis moving. It can be used both for positioning and speed movements. The motion can be stopped with Normal stop or Quick stop. You define this in the "Stop mode" dropdown list.
Normal Stop
With a normal stop, the motion is decelerated along the parameterized deceleration ramp. Without Abort: The motion can be resumed with the MCC command "Resume motion". In this case, no other commands can be issued to the axis between the stop command and the resume command. With Abort: The motion cannot be continued. With a normal stop you can also define whether the entire motion, the basic motion or only the superimposed motion should be stopped. You define this in the "Selection" dropdown list.
Quick stop
With quick stop the axis is stopped by the interpolator and is not switched into the follow-up mode. The motion cannot be continued. In addition, the axis is disabled for further motion commands. This state can be removed using "Remove axis enable" or "Reset object". Quick stop within defined period: The motion is stopped within the parameterized time frame (tab: "Dynamics", parameter: "Time for deceleration"). Quick stop with actual value-related emergency stop ramp: The motion is stopped by the interpolator via the Emergency OFF ramp (dialog box: "Limits", tab: "Dynamic response", parameter: "Stop with preconfigured ramp"). A following error is taken into account before stopping. Quick stop with maximum deceleration: The motion is stopped by the interpolator with the max. dynamic values (dialog box "Limits", tab "Dynamic response", parameter "Acceleration"). Quick stop with dynamic values: The motion is stopped with the parameterized dynamic values (tab: "Dynamics").
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MC-SMO-SYS Axes and Drives in SIMOTION
Continue Motion
Selection
SIMOTION
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Continue motion
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All motion
Basic motion
Superimposed motion
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Using the "Continue motion" command, interrupted motion can be resumed. It is only possible to resume motion, which was stopped using the stop mode "Normal stop without abort". You can choose whether to resume all motion, only the basic motion or only the superimposed motion. The axis must not receive any new motion commands between interruption and resumption of the motion.
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Page 43
MC-SMO-SYS Axes and Drives in SIMOTION
Homing Axes with Incremental Measuring Systems
Homing type
SIMOTION
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09.02.2012 MC-SMO-SYS_05.44
Active homing Passive homing Set home position Set home position relative
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Home axis
In the case of an incremental measuring system, the machine must be homed every time it is switched on. Homing is initiated with the "Home axis" command. Additional settings can be made in the "Homing" dialog for the axis configuration An axis is allocated the homed status, if the axis coordinate system of the control was aligned with the homing signal.
Homing type
For incremental measuring systems, the command selects the following homing types: Active homing (default value) In this case, via the configuration in the wizards for the axis configuration (Dialog: "Homing") it is defined which of the three following homing types will be executed (see the next page): • Homing only with zero mark • Homing with reference cam and zero mark • Homing only with external zero mark Setting the current position value: The current axis position is assigned to the value of the home coordinates. No active traversing motion takes place. Relative direct homing: In this particular case, the axis coordinate system is shifted by the value of the home position coordinate. The axis does not move. Passive homing: Contrary to active homing, as a result of the homing command, no active traversing motion takes place. In fact, the homing command is now effective in parallel to the traversing commands, which must be issued from the user program. The motion command can be triggered before or after the homing command. If the conditions for detecting the homing mark are fulfilled, then the axis is homed corresponding to the sequence defined when configuring.
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Page 44
MC-SMO-SYS Axes and Drives in SIMOTION
Active Homing with/without Zero Mark . . .
Travel range Left travel limit
Homing mode • Homing output cam and encoder zero mark • Zero mark only • External zero mark only
SIMOTION
Zero marker
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Right travel limit
Position encoder
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Homing mode
With active homing of an incremental measuring system the settings in the axis configuration are evaluated. You can choose from the following possibilities in the "Homing mode" selection box: Homing with homing output cam and zero mark: The homing command initiates motion towards the homing cam. After passing the reference cam, SIMOTION synchronizes with the next encoder zero mark. After this, the axis is traversed through the home position offset and then the actual position is set to the "homing position coordinate) . When homing with "Bero and reference cam" the homing cam signal must be connected to an input on the control (outside the process image, i.e. >= 64). The homing cam is "1"- active. Homing with zero mark only: This type of homing is valid for axes with only one zero mark over the complete traversing range (usually rotary axes). The homing command initiates motion towards the homing cam. When the zero mark is passed, the measuring system of the axis is synchronized. After this, the axis is traversed through the home position offset and then the actual position is set to the "homing position coordinate". Homing with external zero mark: The homing command triggers a movement. The measuring system of the axis is synchronized once the parameterized edge of the external zero mark signal is detected. The axis is then moved by the amount of the home position offset. When referencing with "External zero mark only", the signal must be connected there where the encoder value is also detected, i.e. at the drive, at the ADI4 or at the intended Bero inputs of the C2xx.
Reversing cams
From V4.1, for active homing it can be selected as to whether a dedicated reversing cam is used – or the hardware limit switch is used as reversing cam. If, when homing, the axis reaches the reversing cam, then the axis is automatically traversed in the opposite direction.
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Page 45
MC-SMO-SYS Axes and Drives in SIMOTION
Passive Homing with/without Zero Mark . . .
Homing mode • External zero mark only
Parameterization on the drive: P495: Encoder 1 substitute zero mark: e.g. DI 9
SIMOTION
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Note
For a digital coupling, drive homing is initiated via the encoder control word_1. Drive parameters are used to define whether the drive synchronizes to the encoder zero mark or to an external signal at the drive. SINAMICS S120: P495[n]: External zero mark for encoder n In addition, P490 of the CU to invert the signal SIMODRIVE 611U: P879.13, in addition P660 = 79 (I0.n external zero mark).
Data transfer from the drive
From V4.0 and higher, by pressing the button "Accept data from the drive", parameter settings from SINAMICS drives can be transferred from the offline data management all the "Start to" into SIMOTION SCOUT. Depending on the setting of parameter P495, the associated selection in the homing mode to zero mark or external zero mark is set.
Homing required
Homing required "Yes": Software limit switches only become active after homing. Absolute motion and synchronous motion commands are rejected (error 40108: Axis not homed. Relative motion is permissible. Homing required "No": Software limit switches are always active (if activated). All motion and synchronous motion commands are permissible.
System variables
In the system variable .positioningState.homed it can be queried as to whether an axis was homed with incremental encoder. For axes with absolute encoders, this system variable is statically set to "Yes" Using this system variable, it is not possible to evaluate whether an absolute encoder was adjusted.
TO restart
Using a TO restart, the axis is reset to the state: • .positioningState.homed = no Such a restart can be initiated from the user program or from SIMOTION SCOUT using the following system variable: • .restartactivation = activateRestart
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Page 46
MC-SMO-SYS Axes and Drives in SIMOTION
Adjusting an Absolute Encoder
Homing type
Absolute encoder adjustment with specification of the position value Absolute encoder adjustment
SIMOTION
Absolute encoder offset
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09.02.2012 MC-SMO-SYS_05.47
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Absolute encoder adjustment
When commissioning the axis, if it was assigned an encoder type "Absolute encoder" or "Absolute encoder, cyclic absolute", then the "Absolute encoder adjustment" entry can be selected in the selection field "Homing type". When issuing this command, the absolute encoder offset from the "Homing" tab is taken into account in the instantaneous encoder actual value. For the "Absolute encoder calibration with specification of the position value", the specified position actual value is calculated with the actual axis position. The difference is saved as absolute encoder offset in the retentive memory area. There is no active traversing motion. The adjustment must generally be repeated in the following situations: • After an OVERALL RESET of the control • After downloading the relevant access configuration data • When the offset data is lost, e.g. when the battery voltage fails (D4x5, ) • After separating the mechanical connection between encoder and load, if the connection could not be reproduced exactly.
System variables
Using the following system variables it can be evaluated as to whether an adjustment was performed for an axis with absolute encoder: • . AbsoluteEncoder.AbsoluteEncoder[1]. ActivationState Further, in the following system variables, the total offset that has been included can be read out • . AbsoluteEncoder.AbsoluteEncoder[1]. TotalOffsetValue
Notes
• •
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In the "Homing" dialog it can be set whether the value has been taken into account in absolute terms or in addition ("Absolute encoder offset is used"). An axis with absolute encoder should not be homed using the function "Setting the position actual value" as the offset between the encoder value and the position actual value is not saved in the retentive data and displayed in the corresponding system variables as is the case for the absolute encoder adjustment. Page 47
MC-SMO-SYS Axes and Drives in SIMOTION
Setting the Reference System Shift measuring system
Reference system
Setpoint reference
Actual value reference
Relative
SIMOTION
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09.02.2012 MC-SMO-SYS_05.48
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Shift measuring system
Using the command, shift measuring system, you can redefine the actual and setpoint position of an axis. The command can either be programmed, referred to the actual value or the setpoint. Both values are always changed.
Axis
Here, the axis is specified, for which the position should be newly set. All positioning and synchronous axes, which are configured on the device are listed.
Position
The new position value is entered here. The value can be directly entered or as a variable or formula.
Typ
The position type is selected here. • absolute / actual value reference The programmed position is set as a new actual value, and the setpoint is corrected, taking into account the following error, and set. • absolute/setpoint reference (default value) The programmed position is set as a new setpoint, and the actual value is corrected, taking into account the following error, and set. • relative The programmed position is added to the actual setpoint or actual value.
Note
By setting the actual value system using the command "Shift measuring system", contrary to the command "homing, set the actual position value", the original positions of the software limit switch are not changed. The permissible traversing range therefore remains unchanged.
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Page 48
MC-SMO-SYS Axes and Drives in SIMOTION
Diagnostics of Axes or Drives - Service Overview Target system -> Service overview
Extended...
SIMOTION
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Service Overview
With this function it is possible in the online mode to quickly obtain an overview of the state of all configured axes. Selected system variables are displayed here together with their respective status. The status is displayed using colored lamps. Green lamp: Axis (system variable) is active/on or axis is stopped. Red lamp: An error is present. Yellow lamp: Axis is in motion (constant velocity, acceleration, deceleration) or an alarm is present. Gray (no LED): Axis (system variable) is not active.
Example:
Status of the position control (servomonitoring.controlstate): Green lamp: position control is active Gray: Position control is not active
Extended...
A list with additional system variables is displayed when you click the "Expanded..." button. You can select additional system variables from this list for which you want to display the status in the "Service overview". You can select them in the open screen by checking the checkbox in front of the system variable.
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MC-SMO-SYS Axes and Drives in SIMOTION
Diagnostics of a TO - Querying the System Variables
1. Select axis
2. Symbol browser
SIMOTION
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09.02.2012 MC-SMO-SYS_05.50
SITRAIN Training for Automation and Drive Technology
System Variables
You can monitor and modify system variables via the symbol browser. You can query for example the entire status of a command execution or of an axis motion via system variables. This allows you to carry out a detailed analysis of all types of motion and execution, in particular if you use it together with the trace function. You can access system variables: • Within the SIMOTION device from all programs • From HMI devices System variables can be monitored and controlled via the symbol browser. System variables can be also combined in separate application-specific watch tables, for example when commissioning.
Procedure
To monitor the actual values of system variables of the technology object, proceed as follows: 1. Switch SIMOTION SCOUT into the online mode. 2. Select the required technology object in the project navigator. 3. Select the "Symbol browser" in the detail view. The system variables are displayed for the TOs.
Online Help
You can display the associated online help for the individual system variables. To do that, proceed as follows: 1. Press the key combination + . A question mark is displayed next to the mouse cursor. 2. Now click on the row with the system variable for which you required extended help. The online help for the selected system variable is displayed.
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Page 50
MC-SMO-SYS Axes and Drives in SIMOTION
Significance of the Service Display Name
Significance
Position control status (servomonitoring.controlstate):
Green: position control is active for the axis Gray: position control is not active. Setpoint at the pos. control output is 0.
Operational status (control) Technological alarm on axis (error)
Green: axis can be moved by motion commands Gray: axis is in follow-up mode Red: Technological alarm present on the axis Gray: There is no technological alarm
Cycl. drive interface active (actormonitoring.cyclicinterface)
Green: cyclic data transmission to drive active via PROFIBUS Gray: drive is not in cyclic operation
Drive enable (actormonitoring.drivestate)
Green: drive enable (ramp-function generator) is active Gray: no drive enable
Power enable (actormonitoring.power)
Green: power enable (enable OFF1, OFF2 and OFF3 and operation) Gray: no power enable
Drive error (actormonitoring.driveerror)
Red: error on drive (error active/power-on disable) Gray: no error on drive
Status of axis motion (motionstatedata.motioncommand)
Green: axis is not moving Yellow: axis is moving
Velocity-related standstill signal (motionstatedata.Stillstandvelocity) Axis homing status (positioningstate.homed)
Green: axis is not moving (signal mainly used for speed-controlled axes) Gray: axis is moving Green: axis is homed (only for axes with incremental encoders) Gray: Axis is not homed
SIMOTION
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System Variables
In the system variables a technology object, e.g. an axis, provides information about its current status. The system data of an axis TO will therefore display information such as position setpoint, actual position value, following error in what is referred to as system variables. In addition to the above listed system variables, additional information is displayed about the setpoint and actual positions or following error. Further, clicking on the "Extended..." button displays more information about the axes.
Actual Position
Displays the current actual position of the axis. The actual position is derived from the actual value transferred by the encoder system of the drive.
Setpoint Position
Displays the setpoint position of the axis as calculated by the interpolator. The difference between setpoint and actual position is called following error. The following error is the reference variable within the position controller for calculating the speed setpoint.
Difference between Setpoint and Actual Position
Displays the following error within the interpolator level.
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Technological Alarms Alarm display and acknowledgement: •
Display and acknowledge in SCOUT
•
Display and acknowledge via HMI
•
Acknowledge via the user program
•
Query and evaluate in the user program
Software limit switch
Alarm 40106: SW limit switch reached
Alarms
Position encoder (linear scale)
SIMOTION
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General
The complete technological functionality of SIMOTION is provided in the form of TOs. For example, the TO positioning axis has the complete functionality for the position control of an axis. To use this functionality in the user program, the TO provides various system functions (commands), e.g. "Position axis" to position an axis. In this constellation, two basic fault possibilities can occur: • The command at a TO cannot be executed. In this case, the return value of the function provides information about the cause. • When processing the command, the TOA itself identifies when the function required by the application cannot be executed or not completely and then returns certain events or states. In this case, a TO alarm is generated. • Example: „50102: Following error monitoring window has been exceeded" (fault) „50006: Activation/deactivation of synchronous operation executed directly" (note)
Technological alarms
If an event (fault, note) occurs at a technology object, then this outputs a "Technological Alarm". TO alarms can be evaluated and acknowledged in different ways: • Displaying and acknowledging in the online mode of SIMOTION SCOUT • Displaying and acknowledging via HMI • Acknowledging via the user program • Querying and evaluating in the user program (TechnologicalFaultTask).
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Configuring Technological Alarms
2. TechnologicalFaultTask
3. Alarm configuration
4. Select TO
5. Configure alarm
1. Execution system
SIMOTION
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SITRAIN Training for Automation and Drive Technology
Alarm configuration
Generally, alarms that occur at a technology object have an impact on the system. After creating the technology object, for each alarm a certain behavior is preset (default setting). Depending on the TO alarm, it is possible to modify the preset behavior. For the TO alarms, a distinction is made between effects on the technology object itself (local behavior) and the effects on other technology objects and/or the execution system (global behavior). By specifying the error activation it can be defined as to whether the alarm is to be activated immediately, after repeated occurrences of an error or after a certain period of time. Some alarms can be completely suppressed, for example to suppress unimportant messages. • Example: Alarm: 30002: Command aborted.
Local behavior
With the local behavior you define how the technology object involved should behave when an alarm occurs and how additional commands for the TO should be handled. When an alarm response occurs (except for NONE), the command decoder is always stopped. Any programmed commands issued subsequently are rejected. Command execution can continue after the alarm has been acknowledged in cases where the global error response for the alarm does not automatically require a Power ON.
Global behavior
With the global behavior, the impact of a TO alarm on the execution systems described. The following actions can be set depending on the respective TO alarm. • NONE: no response • START TechnologicalFaultTask With this task, the user can respond to the TO alarm with an application-specific response. If there is no program assigned to this task, the system switches to the STOP state. • STOP: All technology objects and the user program are inactive. • STOPU: Only the user program is inactive.
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Acknowledging Technological Alarms
Acknowledge specific TO alarms Acknowledge TO alarms
SIMOTION
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SITRAIN Training for Automation and Drive Technology
Acknowledge TO alarm
This command can be used to acknowledge all alarms of one or more technology objects (such as axes, cams, etc.). You can specify the axes, cams, etc. for which the alarms are to be acknowledged via checkboxes in the individual parameter dialogs. Several objects can be simultaneously selected. All of the objects, which are defined on the device, can be selected. The checkbox "Acknowledge all alarms" means that all alarms for all technological objects can be acknowledged.
Acknowledge specific TO alarm
The command acknowledges all or one specific alarm at a technology object. With alarm-specific acknowledgement, you can enter the required alarm number in the "Alarm No." entry field. The associated alarm text is then automatically displayed in the "Alarm text" dropdown list. Conversely, you can also select an alarm text from the alarm list. The corresponding number is then automatically displayed in the "Alarm No." box.
Note
From V4.0, using the system function _getAxisErrorState(..) alarms present at a TO axis can be read out. This function provides information on whether axis alarms have occurred and how many. Further, supplementary information on this error are returned as LREAL value.
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MC-SMO-SYS Axes and Drives in SIMOTION
Using the Technology Object Trace (1) TO trace
Start trace recording
SIMOTION
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09.02.2012 MC-SMO-SYS_05.55
Event selection, TO trace
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TO trace
The commands at a technology object and accesses to system variables and configuration data of the technology object can be traced using the TO trace function. In SIMOTION, technology objects can be influenced by configuration data, system variables, and commands during runtime. With the new TO trace, all events affecting a technology object can be recorded in real-time and displayed in detail in a chronological sequence in SIMOTION SCOUT. This results in a significantly improved detection of sporadic errors in the application and as a consequence, commissioning is speeded up.
Procedure
1. Activate an online connection to the target system and select the required SIMOTION device in the project navigator. 2. Call the window of the TO trace from the entry "TO Trace" of the context menu or using the corresponding button in the toolbar. 3. In the "Technology object" list, select the required TOs for the trace recording. 4. Using the button: . . . at the end of the line for each TO, the dialog to parameterize the trace function can be opened. 5. Under the individual tabs, parameterize: settings, commands, configuration data and system variables, how many and which events are to be recorded. Commands, configuration data, and system variables are always selected as the default setting. Signals can be deselected at the individual tabs. 6. Load the parameterization into the target system and start the trace by pressing the "Start TO trace" button.
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MC-SMO-SYS Axes and Drives in SIMOTION
Using the Technology Object Trace (2)
Uploading trace data
SIMOTION
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Continued
7. Select the "Recorded data" tab to be able to evaluate the recorded events. Load the recorded data into SIMOTION SCOUT by pressing the "Upload data" button. The events (writing configuration data or system variables, commands to the TO) are displayed in the correct sequence with timestamp and actual execution status.
Note
When displaying the execution status of a command, pay special attention to the following: As command execution advances, the more information can be read out concerning the relevant commands. This means that for commands that have already been completed, the execution status (EXECUTED or ABORTED) and a possible error code can be determined. As the TO trace takes a snapshot, this information is based on the situation at the time that data is read out. The status is not updated automatically once the command has been completed. The status can be updated by reading out again.
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MC-SMO-SYS Axes and Drives in SIMOTION
If You Want to Know Even More
SIMOTION
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Note
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The following pages either contain additional information or are used as reference to complete a specific topic.
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MC-SMO-SYS Axes and Drives in SIMOTION
Using Axis Data Sets Configuration -> axis data sets
SIMOTION
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Axis data sets
For the TO axis, SIMOTION supports the concept of data sets as well as data set changeover. Various data sets are used, if during the runtime: • the actual encoder must be changed • parameter settings of the controller data must be changed The configuration data, which belong to the axis data set(ADS), can be viewed under the axis data sets of the configuration dialog of the axis tab. Data sets must be defined and activated as a group because some data, for example, controller data, can only be activated simultaneously in groups to ensure consistency of the controller and function. When configuring, several data sets can be created for one axis. Further, it can be defined as to which data set should be active after powering up.
Activate data set
Using the ST system function _setAxisDataSetActive() or the MCC function "other data sets can be selected during the runtime. If another encoding is assigned in the new data set, then the system changes over to the active measuring system. From this point in time, the actual positions of the position control are supplied from the new encoder system. Using the system function _setAndGetEncoderValue() or using the MCC function "Synchronize measuring systems", both measuring systems can be synchronized before the changeover. This will avoid unwanted compensating motion of the position controller if differences in position are identified. If the encoder systems are not adapted, then the resulting speed setpoint step (jump) at the position control output via the time constant "Time constant for smoothing of manipulated variable changes as a result of controller switchover" will be smoothed in the dialog box "Axis_n -> Limits -> Dynamic response".
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MC-SMO-SYS Axes and Drives in SIMOTION
Adding an Encoder to an Axis Configuration -> Encoder configuration 3. Assign encoder 1. Add
2. Create new encoder
SIMOTION
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Encoder configuration
Frequently, a data set changeover is required, if, for an axis, various encoders are used, for example. • Motor measuring system (motor encoder) • Additional direct measuring systems (linear scale) This means that up to 8 encoders can be created for the axis. All of the created encoders are internally active, and the measured values are updated cyclically. Using the "Encoder number" entry, in the axis data sets you can define which encoder is used for the position control.
Automatic adaptation
The adaptation of relevant drive and encoder data is, from SIMOTION V4.2 in conjunction with SINAMICS S120 from V2.6.2 and higher, automatically activated. The encoder parameters are automatically determined and adapted during the runtime. This is not possible for "older" drives (SIMODRIVE, MASTERDRIVES) or for encoders that are directly connected to PROFIBUS DP, and which are supplied via message frame 81 (see the above example). In this case, the encoder must be manually configured.
Add 2nd encoder
To create a 2nd encoder for an axis, to start a message frame must have been configured with the encoder values for the encoder in HW Config. This can either be done by directly inserting a PROFIBUS encoder (for example SIMODRIVE sensor isochrone via message frame 81) from the HW catalog or providing additional encoder values via one of the message frames (message frames) 4, 6, 106, … to a drive system with a 2nd encoder. A 2nd encoder is configured in SIMOTION SCOUT using the screen form: Configuration -> Encoder configuration. A new encoder can be added to the axis TO using the "Add" button. The new encoder can be connected with the message frame data in HW Config via the "Assign encoder" dialog. For encoders, which cannot be automatically adapted during the runtime, then the necessary settings must be made for the encoder type, mode and encoder resolution (see the following pages).
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Basic Configuration - Encoder Type and Mode
Encoder type: • Absolute encoder • Absolute encoder, cyclic absolute • Incremental encoder
Encoder mode
For incorrect parameterization (compare with r979 in the drive):
• • • •
Square wave TTL Resolvers Sine/cosine Endat
Error 20005: Device type: 2, log.address: 1234 faulty. (Bit: 0, reason: 0x80h)
SIMOTION
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Encoder type
From V4.2 and higher, for SINAMICS drives it is possible to directly align the encoder configuration dynamically with the encoder settings for SINAMICS during the runtime. This is not possible for "older" drive systems, for example SIMODRIVE and MASTERDRIVES – or for third-party drives. In this case, the encoder must be manually configured. The required encoder type must first be selected: • Absolute encoder • Absolute encoder, cyclic absolute • Incremental encoder
Encoder mode
The actual encoder type is set in the "Encoder mode" selection field. The following settings are available for absolute encoders: • Endat encoder (encoder data interface) • SSI encoder (synchronous serial interface) The following incremental encoders are supported: • Sine/cosine encoder • Square-wave TTL encoder • Resolvers • Endat encoder
Alarm for incorrect parameterization
If the encoder parameterization in SIMOTION and in the drive differ from one another, the following technology alarm is triggered as soon as an online connection is established between the control and drive/encoder and the TO is loaded to the control. "Error 20005: Device type: 2, log.address: 1234 faulty. (Bit: 0, reason: 0x80h)" The comparison of the parameterization for drives is realized according to the PROFIdrive via a parameter: r979 (SensorFormat). For drives, which do not support parameter r979, the configuration without alarm is considered to be valid.
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MC-SMO-SYS Axes and Drives in SIMOTION
Mode of Operation of an Incremental, Optical Sin/Cos Encoder Capacitor
Scanning plate
Output signals:
Indexing disk
2048 periods per revolution
Photo elements
Light source
Spur B
Spur R
Spur C
Type: ERN 1387 ERN 1381
Reference mark
"Raw signal"
Spur D Additional inverted tracks
A, B, R, C , D
8 ramps per cycle Each ramp is subdivided into 256 steps
2048 cycles
Spur A Resolution with SINAMICS S120 : 2048 * 8 * 256 ≈ 4 million
Spur B
SIMOTION
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Principle
The optical encoder is based on the following principle. Parallel light passes through the lattice grid of a scanning plate opposite the light source onto the grid serving as the measuring standard. The lattice grid distribution on the scanning plate and on the indexing disk are identical The lattice grid on the scanning plate is split up into 4 fields, which, regarding the grid distribution, have spatial offsets of 0º, 90º, 180º and 270º. For relative motion, a bright-dark modulation is created due to the alternating coverage. This modulation is evaluated using 4 photo elements (4 field scanning). These photo elements supply currents that are proportional to the illumination intensity. If the 0º and 180º, as well as the 90º and 270º signals are combined, then 2 sin or cos sequences are obtained.
Raw signals
Encoder output signals, which supply a voltage that can be evaluated (raw voltage signals) have 1 Vpp - raw current signals supply 11µApp.
Resolution
Internally an additional resolution is realized through interpolation (2048 pulses per period). For interpolation with 2048 subdivisions, the resolution is again 11 bits, i.e. 22 bits, which means 222 = 4´194.304 signals per revolution. Example: Ballscrew 10mm pitch, no gear, 2048 pulses per revolution x 2048 sinusoidal oscillation /10mm, i.e. 419 signals/µm or 0.0023 µm/pulse. However, this resolution is only required when determining the actual speed for the closed-speed control inside the drive. In this case, even at low speeds (up to 1 revolution/minute) it must be possible to sensibly determine the actual speed. However, this high-resolution is transferred to SIMOTION (refer to the next page).
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ERN 1387
ERN 1381
Spur A
Settings for Incremental Encoders - "Cyclic Actual Value"
Number of pulses per revolution Fine resolution
G1_XIST 1 31
30
29
28
27 26
25
24
23
Overflows: 0 - 1023
SIMOTION
22
21
20 19
18
17
14
13
12
11 10
9
8
7
6
5
4
3
2
1
0
Encoder pulse number: 2048 Fine resolution: 2048
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Cyclic actual value
The cyclic actual value in Gn_XIST_1 (n = 1 or 2, encoder number) is used by incremental as well as absolute encoders to send the actual position value of the axis in cyclic operation to SIMOTION. SIMOTION cyclically calculates the actual position value of the axis from this value, the leadscrew pitch and the reference point value (with incremental encoders) or the absolute value, which is passed on by absolute encoders after activation. After the converter has been switched on, Gn_XIST_1 = 0 is always output independent of the actual position of the axis. Each traversing movement of the axis is passed on via Gn_XIST_1. SIMOTION interprets the bits in this Gn_XIST_1 in accordance with the settings in "encoder pulse number" and "fine resolution". This interpretation is correct only if the settings in SIMOTION correspond to the settings for Gn_XIST_1 in the converter and, of course, also correspond to the actual data of the encoder.
Fine resolution
The converter does not only output the information on the pulse number to Gn_XIST_1 but also increases the total resolution of the connected encoder by internally sampling the sin/cos signal with sin/cos encoders or resolvers. Resolution: Encoder pulses x 2n (n: fine resolution, no. of bits for internal multiplication • The following applies for the No. of encoder marks: Encoder marks = number of sine signal periods (sine/cos encoder with 1 Vpp) No. of encoder marks = 1024 x pole pair no. (resolver with 12 bit resolution) No. of encoder marks = 4096 x pole pair no. (resolver with 14 bit resolution) The pulse number and fine resolution are entered in parameters in the converter. • The fine resolution for the cyclic actual value Gn_XIST_1 in the converter must be entered in SIMOTION as value = 2n in the input field. An input value of 0 is interpreted as standard multiplication factor of 211 = 2048. In this case 0 is equal to 2048.
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MC-SMO-SYS Axes and Drives in SIMOTION
Mode of Operation of an Absolute Encoder Capacitor Indexing disk
Hall-effect element
Photocouples Light source Scanning plate
Coded disk Gear box
Resolution: 16 revolutions
Binary coding of a mechanical revolution with 8192 positions
Incremental tracks
16:1
Multiturn absolute encoder
Date: File:
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Resolution: 4096 revolutions
Motor speed
Singleturn encoder
SIMOTION
Resolution: 256 revolutions
09.02.2012 MC-SMO-SYS_05.63
16:1
16:1
Type: EQN 1325
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Principle
The optical design corresponds to a sin/cos encoder. In addition, the disks have binary coded tracks, which can be interpreted as coded number of pulses in the incremental track. For 2048 pulses, then at least 11 additional tracks are required, in order to code the position within one revolution (single turn encoder). The absolute traversing distance that can be measured is therefore too low for most applications (for example, 10 mm for a ballscrew with 10 mm pitch/revolution and directly mounted onto the motor). This is the reason that the measuring range has been extended using a 3-stage gearbox. Every step down stage has a ratio of 16:1. As a consequence, the position information only repeats itself after 4096 revolutions or after a traversing distance of 40.96m. The position of the gear wheels in the gearbox are evaluated using Hall elements.
EnDat interface
In order that the traversing distance through the 4096 revolutions can be uniquely represented, the following information must be known. Gearbox position: 3 x 4 bits (16 x 16 x 16 = 4096 revolutions) Pulse number: 11 binary tracks When the control system is switched on, this 23-bit information is transferred from the encoder using the EnDat protocol (EncoderData Protocol). The precise position information is retrieved using the interpolation technique described for sin/cos encoders.
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MC-SMO-SYS Axes and Drives in SIMOTION
Settings for Absolute Encoders - "Absolute Actual Value"
Number of pulses per revolution Fine resolution for act. value in Gn_XIST_1 Fine resolution for act. value in Gn_XIST_2 Number of bits for multiturn resolution + no. of encoder pulses Gn_XIST 2
not evaluated
Multiturn resolution: 4096
Encoder pulse number: 512
Fine resolution: 512
Number of data bits: 21
SIMOTION
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Absolute actual value
When an absolute encoder is connected, SIMOTION retrieves the absolute position of the axis via Gn_XIST_2 (n = 1 or 2, encoder number) after the control/converter has been switched on. From the transmitted value or the stored overflows of the multiturn information, SIMOTION calculates the actual position value of the axis. SIMOTION interprets the bits in Gn_XIST_2 in accordance with the settings for "Data width of absolute value without fine resolution" and the "Fine resolution of absolute value in Gn_XIST2".
Number of data bits
The "Data width absolute value without fine resolution" is obtained from the total of the bits for multiturn resolution and encoder pulse number. The settings in SIMOTION must match the corresponding settings in the converter, otherwise the actual position will not be calculated and displayed correctly after switch on.
Fine resolution
Just the same as for "cyclic actual value", the converter not only transmits information about the number of encoder revolutions (for multiturn encoders) and the encoder pulse number to the higher-level control, but also performs fine resolution. This fine resolution is lower with the "absolute actual value" than with the "cyclic actual value" as the entire information must be stored in a 32-bit double word. This means only 9 bits, i.e. a factor of 512, remain for the fine resolution for standard multiturn encoders with a multiturn resolution of 4096 (12 bits) and an encoder pulse number of 2048 (11 bits). This is the reason that for the "Fine resolution absolute value in Gn_XIST_2" an entered value of 0 is interpreted as a multiplication factor of 29 = 512.
Note
The encoder position word Gn_XIST_2 is used not only for transferring the absolute actual value after switch on but also for transferring the position in the functions: "Measuring input" and "Homing". In this case, however, the position value is coded in accordance with the format settings for the "cyclic actual value", i.e. in accordance with the multiplication factor for the cyclic actual value.
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MC-SMO-SYS Axes and Drives in SIMOTION
Settings for Absolute Encoders - Encoder Type
Encoder type:
"Absolute encoder" Overflows of the multiturn information are not saved in SIMOTION when it is switched off
"Absolute encoder, cyclic absolute": Overflows of the multiturn information are saved in SIMOTION when it is switched off
....
Overflows of multiturn information
Multiturn resolution
Encoder pulses per revolution
Fine resolution
Number of data bits: 23
Encoder information in Gn_XIST 2
SIMOTION
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Encoder mode
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The following two settings are available in the "Axis configuration - Encoder assignment" dialog box in the "Encoder type" field: • Absolute encoder: With this setting, the entire overflows of the absolute actual value, i.e. overflows of the multiturn information are not saved when the SIMOTION is switched off. The next time SIMOTION is switched on, the actual position value is formed from the absolute actual value which is passed from the converter in Gn_XIST_2 to SIMOTION. With a multiturn resolution of 4096 and a leadscrew pitch of 10mm/rev. The result is always a value between 0 m and approx. 40 m. • Absolute encoder, cyclic absolute With this setting, at switched off, the overflows of the multiturn information are stored in the retentive memory area of SIMOTION. The next time SIMOTION is switched on, this information is taken into account for calculating the actual position value. This setting must be made if the absolute encoder with it's multiturn resolution does not cover the complete traversing range of the axis or if, as a result of an unfavorable mounting of the absolute encoder, overflows of the multiturn information occur within the traversing range.
Note
SITRAIN Training for
The overflows of the multiturn information and the value for the absolute encoder adjustment of an axis are deleted in the following situations: • OVERALL RESET of SIMOTION • Download of modified configuration data for the encoder settings for the axis.
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MC-SMO-SYS Axes and Drives in SIMOTION
Settings for Travel to Fixed Endstop
Maximum motor torque --> TypeOfAxis.SetPointDriverInfo.DriveData.maxTorque
SIMOTION
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Travel to fixed endstop
As a result of the "travel to fix stop" command, the monitoring of "traversing to fixed endstop" is activated in parallel to axis motion started using a motion command. In addition, the maximum torque at the drive is restricted to the value specified in the command. Further, the active following error monitoring usual for traversing motion is deactivated. The "Travel to fixed endstop" function assumes that the torque limiting at the drive is supported, i.e. this function can only be performed when using one of the message frames 103, 104, 105, or 106. The command also ensures that a specific clamping torque is maintained after the fixed endstop has been reached. This command can also be used to switch over the clamping torque during active clamping.
Fixed endstop detection
In the dialog "Limits", "Fixed endstop" tab, in the "Fixed endstop detection" field, it can be selected as to how it can be detected when the fixed endstop is reached: • when the following error is exceeded. In this case, in the entry field "Following error to the fixed endstop detection", the required value should be entered, which results in the status "Fixed endstop reached". • when the torque is exceeded: In this case, when reaching the torque programmed at the command for the status "Fixed endstop reached". If the criterion "Fixed endstop reached" is reached, then the interpolator is stopped; however the position control remains active. The axis is now clamped with the torque programmed at the command. The usual traversing commands in the same direction are rejected by the TO, only traversing commands in the opposite direction are permitted. In the system variables moveToEndStopCommand. ClampingState the state "Fixed endstop reached" is displayed. The state "Fixed endstop reached" is canceled if the actual axis position deviates by more than the value specified in the "Position tolerance after fixed endstop detection" (e.g. because the clamping force is overcome, traversing command in the direction opposite to the clamping direction).
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MC-SMO-SYS Axes and Drives in SIMOTION
Travel to Fixed Endstop - "Determining the Reference Torque"
Max. drive torque--> TypeOfAxis.SetPointDriverInfo.DriveData.maxTorque
SIMOTION
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Determining the reference torque
For SINAMICS from V2.6.2 and higher, the reference torque of the motor is automatically adapted by SIMOTION and entered into the corresponding configuration data. .TypeOfAxis.SetPointDriverInfo.driveData.maxTorque All of the reference variables of an axis are listed in the screen form: Configuration -> Reference variables.
Resolution
For the resolution of the torque reduction, from V4.0 two options are available. The setting in SIMOTION is made in the configuration data SetPointDriverInfo.driveData.torqueReductionGranularity (standard motor) or in SetPointDriverInfo.linearMotorDriveData.forceReductionGranularity (linear motor). 1. Setting: "STANDARD" (default setting) - resolution 0.006 % The value of 4000H or 16384 (dec.) in the message frame corresponds to a torque reduction of 100%. In SINAMICS, P1544 must be set to 100 (default setting). 2. Setting: "BASIC" - resolution 1 % The value of 64H or 100 (dec.) in the message frame corresponds to a torque reduction of 100%. In SINAMICS, P1544 must be set to 16384.
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MC-SMO-SYS Axes and Drives in SIMOTION
Travel to Fixed Endstop - "Settings in the Command"
For linear axes: F = Torquemotor x 2 x π x (ηspindle/ S) x (motor revolution / load revolution) F : Force in N Torquemotor : Motor torque in Nm ηspindle : Efficiency of the spindle (no dimensions) S: Spindle pitch in m
SIMOTION
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Clamping value (without unit)
The clamping value is entered in the force unit for the particular axis type, i.e. in N, kN, ... (Newton) for linear axes or in Nm, kNm for rotary axes. If a linear axis is implemented using a standard motor and a ballscrew, then the motor reference torque must be converted to the "reference force" of the linear axis. The following relationship is used for the conversion: F = torquemotor x 2 x π x (ηspindle / S) x (motor revolution/load revolution) F = force M = torque S = spindle pitch (leadscrew.pitchVal) η = spindle efficiency (leadScrew.efficiency) Motor revolution (Gear.numFactor) Load revolution (Gear.denFactor)
Example
In the following example, the reference torque 3.68 Nm of a motor is converted into a reference torque. In this example, the conversion is made without any additional load gearbox, the spindle pitch is assumed to be 10 mm/revolution F = 3.68 Nm x 6.28 / 0.01 m = 2312, 21 N When 231.22 is entered as clamping value in the command, this corresponds to a torque reduction of 90% in the message frame. As a consequence, the drive generates a maximum torque of 0.368 Nm at the motor.
Clamping value (as a percentage %)
When selecting the clamping value as a %, the required max. torque at the drive can be directly entered in units of 0.01. The required maximum torque at the drive of 0.37 Nm then corresponds to an input of 37. When implementing a linear axes via a ballscrew at the motor, then a value of 628.0 must be entered into the system variable userdefaultclamping.clampingvalue.
SITRAIN Training for
Automation and drive technology
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MC-SMO-SYS Axes and Drives in SIMOTION
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