Failure and replacement of components during redundant operation
11.2 Failure and replacement of components of the distributed I/Os
CPU 410-5H Process Automation
198
System Manual, 09/2014, A5E31622160-AB
11.2.4
Failure and replacement of PROFIBUS DP cables
Starting situation
Failure
How does the system react?
The S7-400H is in redundant system mode and
the PROFIBUS DP cable is defective.
•
With single-channel one-sided I/O:
Rack failure OB (OB 86) is started (incoming
event). The DP master can no longer process
connected DP slaves
(station failure).
The LED BUS1F flashes.
•
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.
The LED BUS1F and the LED REDF are
flashing.
Replacement procedure
Proceed as follows to replace PROFIBUS DP cables:
Step
What to do?
How does the system react?
1
Check the cabling and localize the
interrupted PROFIBUS DP cable.
–
2
Replace the defective cable.
The CPUs process the error OBs synchronized
with each other
•
With one-sided I/O:
Rack failure OB 86 (outgoing event)
The LED BUS1F goes out.
The DP slaves can be addressed via the
DP master system.
•
With switched I/O:
I/O redundancy error OB 70 (outgoing
event).
The DP slaves can be addressed via both
DP master systems.
The LED BUS1F and the LED REDF go
out.