Dear Experts,

We have S7-414-4H system in one of the sewage pumping station. On 14 June 2022, both PLC CPU's went into stop mode (Please refer attached photo) and not able put in run mode with warm restart.

With cold restart option, both PLC CPU become in run mode and station is normal.

Now we are trying to find out root cause of stop mode. While checking the diagnostics buffer of both PLC (Please refer attached diagnostic buffer of both CPU), found that there is “cycle time exceeded” message recorded. upon clicking of this message in diagnostic buffer, there is open block option. After clicking this open block option, it is redirecting to the line in FC44 SCL block. Please find attached FC44 SCL program with yellow highlighted line. Also i have attached the screen shot of PLC cycle time once both CPU are in run mode.

So, could you please support us to find root cause of this “cycle time exceeded” error and suggestion to avoid this error in future.

Thank you

Regards

Sachin Patil