Failure And Replacement Of Profibus-Dp Cables - Siemens SIMATIC S7-400H System Manual

Failure and replacement of components during operation
13.3 Failure and replacement of components of the distributed I/Os
13.3.4

Failure and replacement of PROFIBUS-DP cables

Starting situation
Failure
The S7-400H is in redundant mode and the
PROFIBUS-DP cable is defective.
Replacement procedure
To replace the PROFIBUS-DP cables:
Step
1
2
3
198
What has to be done?
Check the wiring and localize the
interrupted PROFIBUS-DP cable.
Replace the defective cable.
Switch the failed modules to RUN.
How does the system react?
With single-channel, one-sided I/O:
•
Rack failure OB (OB 86) is started (incoming
event). DP master can no longer process
connected DP slaves (station failure).
With switched I/O:
•
I/O redundancy error OB (OB 70) is started
(incoming event). DP slaves are addressed
via the DP master of the partner.
How does the system react?
–
–
CPUs process error OBs in synchronism
With one-sided I/O:
•
Rack failure OB 86 (outgoing event)
DP slaves can be addressed via the DP
master system.
With switched I/O:
•
I/O redundancy error OB 70 (outgoing event).
DP slaves can be addressed via both DP
master systems.
System Manual, 09/2007, A5E00267695-03
S7-400H