Runtime Behavior Of The Opc Ua Server - Siemens SIMATIC ET 200AL System Manual

OPC UA communication
9.1 What you need to know about OPC UA
Through the information provided by the OPC UA server
OPC UA servers provide a wide range of data:
● The values of PLC tabs and DB components which clients may access.
● The data types of these PLC tags and DB components.
● Information on the OPC UA server itself and on the CPU.
This gives clients an overview and allows them to read out specific information. Previous
knowledge of the PLC program and the CPU data is not required. You do not need to ask
the developer of the PLC program when PLC tags are to be read. All necessary information
is stored on the server itself (for example, the data types of the PLC tags).
Display of the information of the OPC UA server
You have the following options:
● Online: You have all the available information displayed during the runtime of the OPC
UA server. To do so, navigate (browse) the address space of the server.
● Offline: You export an XML file that is based on the XML schemes of the OPC
Foundation.
Server methods created by the user (FB instance that can be called by an OPC UA
client) are not exported (STEP 7 (TIA Portal) V15), see Providing methods on the OPC
UA server (Page 180).
● Offline with the Openness API: In your program, you use the API (Application
Programming Interface) of the TIA Portal to access the function for exporting all PLC tags
that can be read by OPC UA. This requires .NET Framework 4.0; see TIA Portal
Openness, Automating SIMATIC projects with scripts
(https://support.industry.siemens.com/cs/ww/en/view/109477163).
● If you already know the syntax and the PLC program, you can access the OPC UA server
without first researching the information.
9.1.9

Runtime behavior of the OPC UA server

OPC UA server in operation
The OPC UA server of the S7-1500 CPU starts when you activate the server and download
the project to the CPU.
How to activate the OPC UA server is described here (Page 161).
Response to CPU STOP
An activated OPC UA server remains in operation even if the CPU switches to "STOP". The
OPC UA server continues to respond to requests from OPC UA clients.
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Communication