Hi all! I could use some of your expertise with the next issue.

First some information:

We have one CPU 1516F-3 PN/DP and 16 identical sub stations. They are connected via Profisafe using Scalance XC224 switch. In those sub stations we have two freq. conv. G120 / CU250S-2 PN Vector and one IM 155-6 PN ST with one F-DI and one F-DQ. We are using TIA v15.

My question is: how can we avoid CPU to go to stop mode if one of the sub stations goes out? They are doing independent tasks so there is no need for the CPU and thus all other sub stations to stop if one of them has a fault. This includes intentional black outs, for example maintenance work.

I know that in OB86 I can detect a faulty module but other than that, I'm completely lost. Should I mask out the faulty module signal somehow if the sub stations next to it are okay, or what?

Any help would be appreciated.

BR

thn