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
System Manual, 09/2014, A5E31622160-AB
195
11.2.1
Failure and replacement of a PROFIBUS DP master
Starting situation
Failure
How does the system react?
The S7-400H is in redundant system mode and a
DP master module fails.
•
With single-channel one-sided I/O:
The DP master can no longer process con-
nected DP slaves.
•
With switched I/O:
DP slaves are addressed via the DP master
of the partner.
Procedure
Proceed as follows to replace a PROFIBUS DP master:
Step
What to do?
How does the system react?
1
Turn off the power supply of the central
rack.
The fault-tolerant system switches to single
mode.
2
Unplug the Profibus DP cable of the affect-
ed DP master module.
–
3
Replace the module.
–
4
Plug the Profibus DP back in.
–
5
Turn on the power supply of the central
rack.
•
The CPU performs an automatic LINK-
UP and UPDATE.
•
The CPU changes to RUN and operates
as the reserve CPU.
Exchanging a CP 443-5 in case of spare part requirement
If a CP 443-5 is replaced by a successor module with a new article number, both modules
must always be replaced in the case of redundantly used components.
Redundantly used modules must be identical, which means they must have the same article
number, product version and firmware version.
Follow the steps below:
Step
What to do?
How does the system react?
1
Stop the standby CPU
The fault-tolerant system switches to single mode,
see chapter Step 3: Stop the standby CPU
(Page 159)
2
Turn off the power supply of the central rack.
-
3
Unplug the Profibus DP cable of the affected DP
master module.
–
4
Replace the module.
–