Some time ago I made successful commucnication: s7300(a)-s7200s7(b)-200(c) over MPI. Reading from s7200 was made ins7300with X_GET FB.

Now something happaned that I don't really understand. I have lost communication with PLC (b) (s7200) in the middle of bus. I made few steps to diagnose the probelm but now I am out of ideas.

-x_get gives status 7000, 7000, 7001, 80c2

-replacingposition s7200(c)<->s7200(b) - all the time reads the same plc s7200(c)

-connecting cable PG withUSB/PPI to s7200(b) - everything is ok. I can upload/download program. My parameters refreshes.

-connecting cable PPI to PG/PC plug on the MPI bus - finds s7300, s7200(c), except from s7200(b)

-used new mpi cable to conect only s7300 - s7200(b) - no communication

I am out of ideas what is wrong.

looking forward to any help.

But there isNO communication between PLC's.

Life bit will tell me what I already know.

My antoher question that I came up with.

Is it possible that S7200 MPI protocol stoped working but PPI still works?

I can communicate with s7200 with USB/PPI but not with MPI.