Failure and replacement of components during redundant operation
11.1 Failure and replacement of central components
CPU 410-5H Process Automation
192
System Manual, 09/2014, A5E31622160-AB
Follow the steps below to replace a synchronization module:
Step
What to do?
How does the system react?
1
Replace the synchronization module on the
CPU on which the LED Linkx-OK is still lit.
–
2
Plug in the fiber-optic cable connections of
the synchronization modules.
•
The LEDs IFMxF go out.
If the LED should not go out, you must
replace the synchronization module on
the other CPU.
•
Both CPUs report the event in the diag-
nostic buffer
3
Start the standby CPU.
The system status now changes to Redun-
dant mode.
Starting situation
Failure
How does the system react?
Simultaneous failure of both fiber-optic cables
The S7-400H is in redundant system mode and
both fiber-optic cables fail.
•
Both CPUs report the event in the diagnostic
buffer and via OB 72.
•
Both CPUs become the master CPU and
remain in RUN mode.
•
The LEDs IFM1F and IFM2F are lit on both
CPUs.
Procedure
The described double fault results in loss of redundancy and partial or complete failure of
switched DP or PN I/O. In this event proceed as follows:
Step
What to do?
How does the system react?
1
Switch off one subsystem.
–
2
Replace the faulty components.
–
3
Turn the subsystem back on.
•
LEDs IFM1F and IFMF2F go off. The
LED MSTR of the switched on subsys-
tem goes out.
4
Start the CPU.
•
The CPU performs an automatic LINK-
UP and UPDATE.
•
The CPU changes to RUN (redundant
system mode) and operates as reserve
CPU.