Siemens SIMATIC S7-400H Manual page 121

9.1.6 Failure and Replacement of an IM 460 and IM 461 Interface
Module
The IM 460 and IM 461 interface modules make it possible to connect expansion
racks.
Initial situation
The S7-400H is in the Redundant system
mode and one interface module fails.
Procedure
To change an interface module, perform the following steps:
Step
1 Turn off the power supply of the central
rack.
2 Turn off the power supply of the
expansion unit in which you want to
replace the interface module.
3 Extract the interface module.
4 Insert the new interface module and
turn the power supply of the expansion
unit back on.
5 Switch the power supply of the central
rack back on and start the CPU.
S7-400H Programmable Controller Fault-Tolerant Systems
A5E00068197-04
Failure and Replacement of Components During Operation
Failure
What Has To Be Done?
How Does the System React?
Connected expansion unit is turned off.
Both CPUs report the event in the
diagnostic buffer and via OB 86.
How Does the System React?
The partner CPU switches to Solo
mode.
-
-
-
CPU performs automatic LINK-UP
and UPDATE.
CPU changes to RUN and
operates as the standby CPU.
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