S7 300- CPU GETTING SF ERROR

Dear All

We are facing a complicated issue (for us it is complicated). CPU is showing SF error and coming to halt randomly, sometime it runs for 8 hours, sometime 1 hour- pattern is random.

1. We have done diagnostic- (please find the attached diagnostic files)

2. Most of the time we are getting these two errors:

Event 3 of 138:  Event ID 16# 5961
Parameter assignment error in parameters for central S7 modules
subrack 1
Slot    4
Error type: Slot configured for CPU is not occupied or is occupied by a place holder, or a station has failed or the switched I/O system has lost its redundancy.
Data record number: 255
Operating mode: STOP (internal)
External error, Incoming event
12:01:38.255 AM  03/10/1994
(Coding: 16# 5961  FF04  C17B  0065  0004  FF05)

Event 29 of 138:  Event ID 16# 5961
Parameter assignment error in CPU module parameters
Parameter: module type
Input address:      8 of the module with parameter assignment errors
Error type: configurable slot empty
Operating mode: STARTUP (warm restart)
External error, Incoming event
12:01:35.624 AM  03/10/1994
(Coding: 16# 5961  FF06  C17B  0001  0008  0B08)

3. We did many things:

a. We have separated power supplies to the PLC IOs and CPU with separate ground.

b. We have insulated BACK PANE from the body of the electrical panel.

c. We have bypassed the 0-10 V connections of the drives, because we are thinking some kind of AC-DC voltage superimpose.

But so far no improvements found. Please guide us - how to solve the issue.

Hello,

You material configuration is the same like you program?