Dear Experts,

I have encountered a situation where RIO Panel connected to SIS PLC through Profibus repeater was disconnected after SMPS failure.
It was observed that both PLCs went to STOP mode at the same time.
When PLC switch changed to STOP and RUN again both PLCs went in Run mode with Active BUS fault and
Battery Fault on CPU1

After resolving issue with Repeater SMPS , all faults were cleared.

As CPU was placed in Run mode as to resume the process, diagnostic buffer for CPU stop was lost.

During shutdown , similar conditions were tried to be simulated but in any condition PLCs remain in RUN mode
and Complete stop was not observed.

Please suggest any possible reasons for this failure .

PLC - S7-414-5FH