Dear All,

I have 2 S7-400 PLCs with CPU416-2 DP. These 2 PLCs are communication with each other by MPI through the X1 port of the CPU. Suddenly the communication got interrupted for about 15 to 20 seconds and came back. But this unfortunately created a breakdown in the process line due to interruption of data between the PLCs. The only thing was found is the Ethernet CP was giving fault and we reset the CP. But I believe this have nothing to do with MPI problem. I attach the diagnose report of one of the 2  PLCs. The other one is the same. 

Please advise what could be the reason for such problem.

farra

Hi farra,

Hazard_7

Hi farra,

The frequently repeated error is the following:

Event 1 of 120:  Event ID 16# 6881

Interface error outgoing

Interface ID: X1, MPI/DP/PROFINET

Operating mode: RUN

External error, Outgoing event

06:14:33.756 AM  08/21/2023

(Coding: 16# 6881  FF08  C050  0001  0000  0000)

The possible causes are:

1. Check the connected cables, connectors and modules.
2. Was anything changed or added at the time of the error?
3. Check the structure of the system for EMC guidelines.
4. Should the behavior occur more often and everything mentioned can be excluded.
5. CPU may need to be repaired
   

 Dear Hazard_7,

Thanks for your reply and here is my feedback:

1. Check the connected cables, connectors and modules.  --> Done and no issues found
2. Was anything changed or added at the time of the error? --> No
3. Check the structure of the system for EMC guidelines.   --> No issue found as per EMC requirements
4. Should the behavior occur more often and everything mentioned can be excluded.
5. CPU may need to be repaired.--> No fault indiaction on the CPU