Siemens SIMATIC CPU 410 System Manual page 230

Replacement of failed components during redundant operation
13.1 Replacement of central components
Starting situation
Failure
Simultaneous failure of both fiber-optic cables
The S7-400H is in the redundant system state
and both fiber-optic cables fail.
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
1
2
3
4
230
What to do?
Switch off one subsystem.
Replace the faulty components.
Turn the subsystem back on.
Start the CPU.
How does the system react?
Both CPUs report the event in the diagnostic
•
buffer and via OB 72.
Both CPUs become master CPU and remain
•
in RUN.
The LEDs IFM1F and IFM2F are lit on both
•
CPUs.
How does the system react?
-
-
LEDs IFM1F and IFMF2F go off. The
•
LED MSTR of the switched on subsys-
tem goes out.
The CPU performs an automatic LINK-
•
UP and UPDATE.
The CPU switches to RUN (redundant
•
system state) and operates as standby
CPU.
CPU 410 Process Automation/CPU 410 SMART
System Manual, 05/2017, A5E31622160-AC