PCo - Connection retries to OPC UA Server after Agent Restart

[dennis_schoeneborn]

Hi everyone,

we have following problem.

The OPC UA servers on the machines are shut down or de-energized together with the machines. If the PCo instance with the agents is restarted over the weekend due to maintenance or similar, the agent will only try to connect to the de-energized OPC UA server once. After that the service / agent goes into a fault state.

If the PCo loses the connection to the OPC UA servers during the execution of the service / agent, you can set the "Reliable connection" tab to retry.

Is there something like this for the initial connection setup when starting the service / agent?

Such a configuration would help us a lot.

[Kevin_Hunter · Accepted solution]

Hi Dennis,

Please reach out to me by email (kevin.hunter@sap.com) and I can send you a white paper I wrote a few years ago that can automatically restart faulted connections. This may help you.

Thanks

Kevin

[alexander_teslyuk]

Hello Dennis,

PCo Agent can restore a connection if it has already been established but got interrupted. It works according to the Reliable Connection settings.

However, in the described scenario the Agent starts while the source system is down. In this case we are talking not about restoring the connection but about yet establishing it. Let me cite the application help to illustrate the same Reliable Connection Tab - SAP Help Portal

"...Maximum number of connection attempts before the connection counts as failed". Meaning the already established connection.

There are, however, the settings for the startup itself Host Tab - SAP Help Portal

Point 5: Automatic (Delayed Start)

Point 7: Startup Timeout

Please, try to use the delayed startup if the source system is started basically at the same time.

Or create a custom Windows service that will be started only with/after the source system Define this Windows Service as dependent, also use the startup timeout value accordingly.

Best regards,

Alex

[dennis_schoeneborn]

Hello Alexander,

thank you for your answer.

But this does not fit my problem. Maybe some more information. The PCo instance runs on a central VM, while the UPC UA servers run on separate PLC machines.

The problem occurs when the PLC is not "online" and the PCo agents or the whole VM is restarted.

Maybe there is actually no solution for this problem ...