SIMATIC WinCC Open Architecture Forum

Hi All,

We are currently having an issue with our S7+ driver connection to a pair of redundant S7-1200 PLC's. We currently have a pair of PSS servers that are connected to our separate PLC's which have the same software downloaded to them. What we are finding is that when we have a connection to both PLC's let's call them A and B. If our current connection is to A and for some reason we lose connectivity, the system detects the disconnection as seen in the logviewer. The problem lies with the failover, where the system may have failed over to connection B we don't receive any signals nor can we send any commands. When we monitor the "status" -> "State Details" in the S7+ PLC connection we find that connection B's operating state is running.

We have tried configuring the PLC connection as a standalone connection to each PLC and they work with their respective connection. The problem only occurs when the PLC connection is setup with redundancy.

I have attached the relevant logs and a sequence of screenshots that will assist with explaining the problem.

Your posting does not contain any logs or screenshots.
If you need assistance we suggest to use the official Siemens Industry Support instead of the WinCC OA Forum.
https://www.winccoa.com/support.html

Best Regards
Leopold Knipp
Senior Support Specialist