It should not be exceeded. Check the logic in software for endless cycles. What is the profibus baud rate? What is the value for max. scan time (HWKonfig->CPU->Properties)? Are you sure that CPU goes in STOP for those reason?
Rate DP 1.5 MB
MAX SCAN 6000ms
after program parameter drive to plc cpu go to stop for example read piw2100 in chart cfc after that cpu go to stop and cycle time very long !!!