Hello,

in your diagnostic buffer are a lot of events. In my opinion do you switch off/on the PLC more than one time.

The access to the I/O byte 144 is no more possible (event 2).

Because the OB122 doesn't exist the PLC going to STOP..

Please load the OB122 to the PLC and read again the diagnostic buffer.
Check also the Profibus connectors.
It could be that you have a contact problem.

If you have more information about the PLC?

regards
CaOd

Hello,

The main problem that is causing your PLC to stop is a hardware fault in the PLC's I/O. This is causing the PLC to stop because OB122 is not present.

While including OB122 is not mandatory, the PLC will stop if it is not present. To prevent the PLC from stopping in this situation, you can use an empty OB. More ideally, you can program it.

After adding and loading the OB, your PLC will go into run mode if there are no other problems. You can then perform troubleshooting and find the hardware problem using the I/O test.

I hope this helps and solves your problem.