Morning all. CPU 1515F-2 PN, TIA V17, ET 200SP station with an F-DI 8x24VDC HF. Channel 2 is a guard door.

Last week the buffer showed "Channel 2: Short-circuit" and the channel passivated. Our electrician found a chafed wire in the door loom and repaired it, and the buffer now says "Channel 2: Fault resolved". But the process value for that channel stays 0 and the QBAD bit in the F-DI DB stays TRUE, with the door closed and the module LED green for that channel.

The only thing that brings it back is a STOP and RUN on the CPU. I tried a second F-DI from stores, same behaviour, so I don't think the module is faulty.

Is there something in the CPU that has to be cleared, or could anyone point me in the right direction?