the Master goes to Stop Mode and the second slave still in RUN Mode

Hello :
please could you help me?:
I have PROFIBUS Mono System Network(One Master(CPU313C-2Dp) & Tow Slave's(CPU313C-2Dp))when any Slave go out from the service ,the Master goes to Stop Mode and the second slave still in RUN Mode.
but I want to keep the Master in RUN Mode too.
What can I do?

Hint: Look in the diagnostic buffer why the CPU goes to stop mode.

Spoiler: It is probably OB86 that is needed. Typically you add OB82, OB85, OB86 and OB122 to avoid the CPU to go to stop mode due to hardware errors.

Thank you so much my problem is solved
could you help me again?
can I know which Station goes out the Service?