SimSci® ®
.
May 2014
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All rights reserved. No part of this documentation shall be reproduced, stored in a retrieval system, system, or transmitted transmitted by any means, electronic, electronic, mechanical, photocopying, photocopying, recording, r ecording, or ot herwise, herwise, without the prior written written permission permission of Invensys Systems, Inc. Inc. No copyright copyright or patent liability is assumed assumed with respect to the use of the information contained herein. herein. Although every precaution has been taken in the preparation of of this documentation, documentation, the publisher publisher and the author assume assume no responsibility for errors errors or omissions. omissions. Neither is a ny liability assumed assumed for f or damages resulting from the use of t he information contained herein. The information in this documentation is subject to change without notice and does not represent a commitment on the part of Invensys Systems, Inc. The software described in this documentation is furnished under a license or nondisclosure agreement. agreement. This software may be used or copied only in accordance with the terms of these agreements. © 2014 by Invensys Invensys Systems, Inc. All r ights reserved. Invensys Systems, Inc. 26561 Rancho Parkway South Lake Forest, CA 92630 U.S.A. (949) 727-3200 http://www.simsci.com/ For comments or suggestions about t he product documentation, send an e-mail message message to
[email protected] . All terms mentioned in this documentation that are known to be t rademarks rademarks or service marks have been appropriately capitalized. Invensys Systems, Inc. cannot attest to the accuracy of this information. information. Use of a term i n this documentation should should not be regarded as affecting the validity of any trademark or service mark. Invensys, Invensys logo, PRO /II, and SimSci are trademarks of Invensys plc, its subsidiaries subsidiaries and affiliates. affiliates.
OPC Unified Architecture Server
Table of
1
Contents
OPC UA Server....................................................................................................................... 4 1.1
Overview ........................................................ ............................................................................................................... ................................................................. .......... 4
1.2
OPC UA Standard ................................................... ........................................................ 4
1.3
Why OPC UA Server? ..................................................... .................................................................................................... ............................................... 4
1.4
General Assumptions about the OPC UA Server ........................................................... 5
1.5
Discovery of OPC UA Server .................................................... ......................................................................................... ..................................... 6
1.6
Procedure to Invoke a Simulation ....................................................... ................................................................................... ............................ 8
1.6.1
Prerequisites ....................................................... ............................................................................................................... ........................................................ 8
1.6.2
Process Steps ...................................................... .............................................................................................................. ........................................................ 9
1.7
Method Calls and Data Access ..................................................................................... 22
1.7.1
1.7.1.1
Close Simulation .................................................. ............................................. 22
1.7.1.2
Save Simulation ................................................................................................ 23
1.7.1.3
Run Simulation ................................................................................................. 24
1.7.1.4
RunChecks ........................................................................................................ 24
1.7.2
1.8
DataAccess ................................................ ....................................................... ............................................................... ........ 25
1.7.2.1
Unit Operations .................................................... ................................................................................................. ............................................. 25
1.7.2.2
Streams ........................................................ .............................................................................................................. ...................................................... 26
Enhancements in the OPC UA Server ................................................ .......................... 27
1.8.1 1.9
Method Calls ...................................................... ............................................................................................................ ...................................................... 22
Certificate based Authentication .................................................... .............................................................................. .......................... 27
Glossary ........................................................................................................................ 31
3
OPC Unified Architecture Server 1
1.1
OPC UA Server
Overview
The OPC UA Server is a communication data server for the different SimSci ® Simulation Software packages. This server is capable of generating data and exposing methods available to access Dynsim® models, PRO/IITM models, and ROMeo ® models through the OPC UA communication framework. Process simulation capabilities are encapsulated as OPC UA services and this is done for simple models (such as material stream or unit operation) as well as for more comprehensive models. With the OPC UA interface, the discovery of services and configuration models are possible along with calculation of the simulation model . 1.2
OPC UA Standard
OPC UA does not replace the existing standards such as OPC, but rather complement them by providing a common interoperability layer for exchanging information and orchestrating processes. OPC UA embodies all the functionality of the existing OPC servers and expands on top of them. Backward compatibility with previous standards will ensure quick adoption on the market. The OPC Foundation has taken many steps to guarantee that the implementation of the standard is relatively a straightforward and easy process. To facilitate the adoption of the new standard and to reduce the barrier for entry, the OPC Foundation has developed an OPC UA software development kit (SDK). The SDK is the entry point to jump-start the existing applications and make them OPC UA enabled. The SDK consists of a series of application programming interfaces and sample code implementations. To that end, the UA specification is written to be platform-agnostic and, for that reason, the SDK comes in different flavors to facilitate adoptions on different platforms. The .Net, ANSI C, and Java sample implementations are provided to OPC Foundation members. Each "flavor" of the SDK is designed to suite special needs in terms of platforms, memory and processor requirements, but all of them are capable to seamlessly interoperate with each other. The .Net version of the SDK is more suited for rich client/server implementation, while the ANSI C version is more suited for thin implementation like embedded devices, where memory footprint and CPU utilization are more important. The Java implementation is more suited for the Web environment and thin clients but can also be used on other environments. Each software vendor picks the implementation they prefer, depending on the unique requirements for performance, cross-platform capability and Internet-friendliness. 1.3
Why OPC UA Server?
The OPC UA Server is designed to handle communications to and from Dynsim, PRO/II, and ROMeo applications. The UA Driver software layer contains all the basic codes to display data and make methods available to any OPC UA Certified Client. This software layer will transmit/receive data and/or send commands to any one of the three supported simulator types namely Dynsim, PRO/II and ROMeo applications. The UA data space in the server is shared by Dynsim, PRO/II, and ROMeo applications to which it is connected. The UA Driver pr oduct and the appropriate adapter software are delivered with any of the supported simulation types. The OPC UA Server is compatible with any OPC UA client that supports standard UA Data Access or UA Method Calls. By using the UA proxy technology developed by the OPC Foundation, this server can support a standard OPC DataAccess client.
4
OPC Unified Architecture Server All the adapters can communicate with the OPC UA Server driver layer through a common interface and the adapters can connect to the OPC UA Server at any time. At present, it is assumed that each adapter is a loadable DLL (Dynamic Linked Library) or exe (Executable file) that can be loaded in the OPC UA Server driver’s address space. Each adapter is capable of being developed independently and new adapters can be developed to support other SimSci® products in future.
Figure 1: Communication Work Flow of OPC UA DA Server
Once the process simulation domain is exposed as an OPC UA information model, and objects such as material streams, unit operations and flow-sheets are instantiated, then the models can be invoked also for off-line use, without any interaction with actual data. OPC UA would then be used as a communication protocol between adapters and any client, be it a standalone user interface or a web server. Although the OPC UA specification is created for distributing applications, and designed for efficient communication when the client and the server are on different machines, the architecture is simplified with the two coexisting on the same machine. 1.4
General Assumptions about the OPC UA Server
The following general assumptions are being made about the OPC UA Server: 1) The initial design of the OPC UA Server uses the OPC UA QuickStart DataAccess server as a starting point. This server makes the assumption that each block (model/stream instance) has a unique name. Therefore if you have two different simulations that are to be operated simultaneously by the server, then the simulations must be handled in different address spaces. 2) A block in the Data Access servers will be equated with a model or stream instance in Dynsim, PRO/II, or ROMeo applications. The OPC Data Access server currently can’t support and handle groups under the block instances. The OPC UA Server code needs to be modified to handle the concept of groups under the block instances. 3) The program assumes that underlying system will return tree branches all the way down to the group level under a particular block (or model instance). The program then operates on this branch. 4) All adapters will have a method(s) to efficiently return tree information (branch and leaf). All adapters will set up the top branch of their tree (i.e. – Dynsim, ROMeo, or PRO/II softwares) to have a method called Open Simulation/Close the simulations.
5
OPC Unified Architecture Server 5) UOM data will be supplied by individual values in the tree but the user will not have access to the UOM function to make global changes through the OPC server. The OPC UA clients (i.e. – Portal) will be responsible for displaying values with different UOMS. At present the UOM for the opened simulation would be in internal units. 6) Initial version of the server will not do any kind of security checking. 7) Adapters will be loadable dlls that come for each product. The PRO/II and ROMEO adapters
will basically call adapter code for the portal application with a few new methods to get tree data structure. 1.5
Discovery of OPC UA Server
The UA Server is discovered by generic clients through a discovery service. The UA solution relies on a special end point called the Discovery Endpoint which is implemented by all UA Servers as well as a special class of servers called Discovery Servers. This end point does not require any security and is used only for providing clients with location and current security configuration for one or more servers. A Discovery Endpoint always supports two methods: FindServers and GetEndpoints. The FindServers method returns the servers known to the Discovery Endpoint. The GetEndpoints method returns the end points supported by the server and all the security information required to connect to these end points. The UA provides an equivalent server called the Local Discovery Server (LDS) which is installed on every machine with a UA Server. The LDS provides a Discovery Endpoint at well-known URLs. Clients have advance knowledge of these URLs and can use them to find the LDS on any given host. The following is an excerpt of the Discovery URL that is part of standard client configuration file (Opc.Ua.Client.Config.Xml). The following snapshot shows Discovery service end point reference from client perspective:
6
OPC Unified Architecture Server
Figure 2: Add Service Reference Window
The order in which the client uses these URLs can be configured, as different systems have different policies. To summarize, the UA Client discovers everything it needs to connect securely with the UA Server using the following steps: 1. Connect to the LDS on the machine and call FindServers 2. Choose a Server and choose a Discovery Endpoint 3. Connect to the Server Discovery Endpoint and call GetEndpoints The following snapshot depicts the discovery process in a sequence diagram:
7
OPC Unified Architecture Server
Figure 3: Discovery process in a sequence diagram 1.6
Procedure to Invoke a Simulation
1.6.1
Prerequisites
To invoke a simulation, the following prerequisites are to be met:
8
OPC Unified Architecture Server •
Ensure that Opc.Ua.DiscoveryServer is running. This server will run as a service post installation of the PRO/II software.
Figure 4: Task Manager View •
1.6.2
Ensure that a generic OPC UA client is installed on your machine.
Process Steps Note: In this case, OPC UA client named UaExpert is used to describe the functioning of OPC UA Server.
To initiate the process of invoking a simulation, you need to start SimSci OPC UA Server 1.1 manually.
9
OPC Unified Architecture Server 1. Go to Start
Programs
SIMSCI
Simsci OPC UA Server 1.1
Figure 5: Shortcut to access Simsci OPC UA Simulation Server 1.1
or
2. Go to C:\Program Files\Common Files\SimSci\OpcUAv1.1\Bin folder
Figure 6: Path for Bin folder
10
OPC Unified Architecture Server 3. Double-click the Simsci.Opc.Ua.SimulationServer.exe to start the server. Now open Windows Task Manager to check that both the Opc.Ua.DiscoveryServer and Simsci.Opc.Ua.SimulationServer services are running.
Figure 7: Windows Task Manager View
4. Double-click the UaExpert icon
on the desktop.
Figure 8: View of UaExpert icon on the Desktop
If the UaExpert client is launched for the first time, then the following certification page is displayed, prompting you to either accept the certification permanently or reject it.
11
OPC Unified Architecture Server
Figure 9: Trusted Certification Page
5. Click Accept this certificate permanently and then click OK. The Unified Automation UaExpert window appears as shown in figure below.
Figure 10: Unified Automation UaExpert Window
12
OPC Unified Architecture Server 6. To add the OPC UA Server to the UaExpert client, click Add Server top menu. Add Server dialog box is displayed.
button from the
Figure 11: Add Server Dialog Box
13
OPC Unified Architecture Server 7. Expand the Local node from the tree structure to view the servers available.
Figure 12: Add Server dialog box depicting Simsci OPC UA Simulation Server
8. As the Discovery Server service is running, the Simsci OPC UA Simulation Server will be observed in the tree structure as a node. Note: You can also do a custom discovery of the server in case of attempting to connect to a remote server machine. You can enter the machine name/IP address of the server machine and add server in custom mode to connect to the remote server.
14
OPC Unified Architecture Server 9. Expand the Simsci OPC UA Simulation Server node.
Figure 13: Add Server dialog box depicting the security options available The three available security settings options are displayed as nodes. 10. Select Sign & Encrypt or Sign from the list of options and click OK. The required server service is added to the client.
Figure 14: Project Window with server added to the project node
15
OPC Unified Architecture Server 11. Now click the Connect Server between the server and the client.
button from the top menu to establish connection
Figure 15: Address Space with PRO/II software installed as a node to the root.
The client displays the nodes of the products (PRO/II software) installed.
16
OPC Unified Architecture Server 12. Expand the PRO/II software group to view the tree structure.
Figure 16: Extended Tree View of PRO/II Software
13. Click Open Simulation option to select it from the list.
17
OPC Unified Architecture Server 14. Right-click Open Simulation and click Call from the context menu.
Figure 17: Calling Open Simulation on PRO/II Software
The following dialog box is displayed.
Figure 18: Call Open Simulation dialog box
18
OPC Unified Architecture Server 15. Specify the Input Value as C:\SIMSCI\PROII93\User\a1.prz.
Figure 19: Open Simulation with input value specified
16. Click Call.
Figure 20: Message for successfully invoked simulation
The message that the simulation is invoked successfully is displayed. 17. Click Close.
19
OPC Unified Architecture Server 18. Collapse the PRO/II software group and expand it again. The invoked simulation is displayed under PRO/II software group as a new node.
Figure 21: Invoked Simulation Tree View
20
OPC Unified Architecture Server 19. Expand the invoked simulation to observe the groups and parameters under it.
Figure 22: View of methods and data accesses associated with the simulation
20. The branch will display all the methods and data accesses associated with the running simulation. 21. The elaborated view of the tree structure is shown in the figure given below.
Figure 23: Expanded tree structure
21
OPC Unified Architecture Server 1.7
Method Calls and Data Access 1.7.1 1.7.1.1
Method Calls Close Simulation
This method is called when you either close the Excel ® spreadsheet or when the simulation is disconnected from the portal. The application is expected to cleanup and close the simulation. This method contains two arguments, namely, Input and Output arguments, as shown in the tree structure below.
Figure 24: Close Simulation Method View
22
OPC Unified Architecture Server User can type-in the string ‘Save’, to save and close the simulation with ‘Close Simulation’ method call. The string is not case sensitive.
Figure 25: Close and Save Simulation with Test Client
1.7.1.2 Save Simulation
Save simulation method is used to overwrite the simulation data base with updated values. For e.g.: If you have subscribed to some variables in the OPC UA Client, you can access those variables to modify based on the server exposed data access levels (Read variables or Read/Write variables). If you modify some parameter values and wants to overwrite the changes to the simulation database, you have to call the Save simulation method. Note: Subscribing to parameters values and merely changing them in the view window of the client does not overwrite the database. One has to call save simulation method in case they intend to save the changes to the simulation. Save Simulation action is not reversible. The initial values would be over written if there are any changes to the simulation.
23
OPC Unified Architecture Server
1.7.1.3Run Simulation
The Run Simulation method is available for single database at any given point of time. It cannot execute simultaneous Run Simulations because of product limitations. It will check whether the server gets appropriate message from the product adapter. The portal calls the RunChecks method before calling the Run Simulation method, so as to allow the product performs the data consistency checks. Based on the result, it will either call the Run Simulation method or display an error/warning message. The Run Simulation method call will run the simulation if it is currently frozen. 1.7.1.4 RunChecks
The portal calls this method before RunCalc method, so that the application can run data consistency checks and issue any warning/error message before running the simulation.
24
OPC Unified Architecture Server 1.7.2
DataAccess
1.7.2.1
Unit Operations
The Unit Operations, when expanded, appears as shown in the figure below.
Figure 266: Unit Operations Data Access View
Unit Operations consists of Models like Compressor, Controller, Flash, MVC, Mixer, Portal Data, Simple HX, and Splitter. Under Models, it consists of Groups like C2CO, C3CO, and PortalData. Under Groups, it consists of Parameters like Basic, Calculations and Results, Compressor Conditions, Feeds and Products, Heat and Mass Balance, PortalData, and Specifications. Under Parameters, it consists of scalar, vector, and string quantities like Description, Name, and Thermodynamic System.
25
OPC Unified Architecture Server
1.7.2.2
Streams
The Streams, when expanded, appears as shown in the figure below.
Figure 277: Stream Data Access View
26
Streams consist of Models like 1, 10, 11, and so on. Under Models, it consists of Groups like PortalData, Name, Description, Phase, and Thermodynamic System. Under Groups, it consists of Parameters like Portal Data that includes scalar, vector and string quantities.
OPC Unified Architecture Server 1.8
Enhancements in the OPC UA Server 1.8.1
Certificate based Authentication
Certificate based authentication is implemented for OPC UA Server 1.1. While connecting to the Server, it is mandatory for any Client to have it’s Certificate placed in the Trust list of the OPC UA Server 1.1. Once this is done, the User can connect to the Server using secured TCP\IP protocol with a Desktop Client or using secured ‘https’ protocol with a Silverlight or an HTML5 Client with a browser or Mobile device. The OPC UA Server provides secured access to the clients connecting through ‘TCP/IP’ and ‘https’ protocols: •
‘TCP/IP’ Protocol When a sample OPC UA Client connects to OPC UA Server by using the ‘TCP/IP’ protocol for the first time, the user is prompted to accept the OPC UA Server certificate to be included in the OPC UA Client Trustee list.
Figure 28 User prompted to accept the Server certificate to be included in the OPC UA Client Trustee list
The user needs to copy the Client Certificate in the Server Trustee List to permit the Client to access the OPC UA Server. Unified Automation UAExpert Client is used for demonstration.
27
OPC Unified Architecture Server
Perform the following steps to copy the Client Certificate in the Server Trustee List: 1. Select the Manage Certificates option from the Settings menu.
Figure 29 Select Manage Certificates option
2.
Click Open certificate Location button.
Figure 280 Browse to Certificate location 3. Copy UaExpert’s certificate and place it in the OPC UA Server Trustee list. The location of the Server list could be found in the Simsci.Opc.Ua.SimulationServer.Config.xml file on the Server machine (C:\Program Files\Common Files\SimSci\OpcUAv1.1\Bin).
28
OPC Unified Architecture Server
•
‘http’ protocol
The user needs to copy the Silverlight Client Certificate in the OPC UA Server Trustee list to permit the Silverlight Client to access the OPC UA Server ‘http’ protocol. •
‘https’ protocol
The user needs to copy the Silverlight Client and HTML5 Client Certificates in the OPC UA Server Trustee list to permit both the clients to access the OPC UA Server using ‘https’ protocol. All the method calls can be accessed through the http/https protocol. The data for the Unit Operations and Streams from the simulation can be viewed or modified by using the http and https protocols.
Figure 291 Simsci OPC UA Server 1.1
29
OPC Unified Architecture Server
The OPC UA Server can be accessed through the sample HTML5 Client by using a tablet or a smart phone through the ‘https’ protocol. The following figure shows the sample HTML5 Client getting connected to the OPC UA Server through the ‘https’ protocol by using an Apple iPad.
Figure 302 Simulation file accessed through sample HTML5 Client through ‘https’ protocol by using an Apple iPad
30
OPC Unified Architecture Server 1.9
Glossary
OTS
-
Operator Training Simulator
XML
-
Extended Markup Language
OPC UA
-
OPC Unified Architecture
Portal
-
Excel Interface to SimSci TM Products
ROT
-
Running Object Table
OPC DA
-
OPC Data Access
Below is a table that gives a brief description about the configuration parameters and its default settings used in the Simsci.Opc.Ua.SimulationServer.Config.xml Sno
Parameter
1
Operation Timeout
2
3
4
5
6
7
8
9
10
Description
The default timeout in milliseconds for operations (used by clients) MaxStringLength The maximum length for a string value in any message MaxBufferSize This value controls how big a block of memory the transport layer allocates Channel Lifetime The lifetime of a Security Token in milliseconds SecurityTokenLifetime This specifies how long a security token can be used without renewal MaxSessionCount The maximum number of simultaneous sessions MinSessionTimeout The minimum session lifetime permitted by the server MaxSessionTimeout The maximum session lifetime permitted by the server MaxBrowseContinuationPoints The maximum number of browse continuation points per session MaxQueryContinuationPoints The maximum number
Default value 600000
Units
millisec
1048576
-
65535
-
300000
millisec
3600000
millisec
100
No.
10000
millisec
3600000
millisec
10
No.
10
No.
31
OPC Unified Architecture Server
11
12 13 14
15
16
17
18
19
32
of query continuation points per session MaxHistoryContinuationPoints The maximum number of history continuation points per session MaxRequestAge The maximum age of an incoming request MinPublishingInterval The minimum allowed publishing interval MaxPublishingInterval The maximum allowed publishing interval MaxSubscriptionLifetime This controls the maximum keep alive count. Smaller publishing intervals will allow large keep alive provided the maximum subscription lifetime is not exceeded MaxMessageQueueSize The maximum number of sent messages kept in the queue for each subscription MaxNotificationQueueSize The maximum number of notifications kept in the queue for each monitored item MaxNotificationsPerPublish The maximum number of notifications in a single publish response MinMetadataSamplingInterval The minimum sampling rate for rarely changing metadata information (such as the server status)
100
No.
600000
millisec
100
millisec
3600000
millisec
3600000
millisec
10
No.
100
No.
1000
No.
1000
millisec
