Siemens SIMATIC PCS 7 CPU 410-5H System Manual page 186

Failure and replacement of components during redundant operation
11.1 Failure and replacement of central components
Procedure
Note
Replacing an SEC
You can replace an SEC by following the same procedure as described above. Here you do
not replace the CPU in step 2, but replace the SEC with an SEC of the same size and then
reinstall the CPU.
Follow the steps below to replace a CPU:
Step
1
2
3
4
5
6
7
Note
Wiring synchronization modules crosswise
If you wire synchronization modules crosswise, i.e. the IF1 interface of the first CPU with the
IF2 interface of the second CPU and vice versa, the two CPUs take over the master role and
the system will now function properly. The LEDs IFM 1 and IFM 2 are lit on both CPUs.
Make sure that you connect the IF1 interface of the first CPU with the IF1 interface of the
second CPU and the IF2 interface of the first CPU with the IF2 interface of the second CPU
when you replace the CPU. Mark the fiber-optic cables before the replacement, if necessary.
186
What to do?
Turn off the power supply module.
Replace the CPU. Make sure the rack num-
ber is set correctly on the CPU.
Insert the synchronization modules.
Plug in the fiber-optic cable connections of
the synchronization modules.
Switch the power supply module on again.
Perform a CPU memory reset on the re-
placed CPU.
Start the replaced CPU (for example, STOP-
RUN or Start using the PG).
How does the system react?
The entire subsystem is switched off
•
(system operates in single mode).
–
–
–
CPU runs the self-tests and changes to
•
STOP.
–
The CPU performs an automatic LINK-
•
UP and UPDATE.
The CPU changes to RUN and operates
•
as the reserve CPU.
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB