Siemens SIMATIC S7-400H System Manual page 194

Failure and replacement of components during operation
13.2 Failure and replacement of components during operation
Starting situation
Failure
The S7-400H is in redundant mode and an
interface module fails.
Procedure
Follow the steps below, to replace an interface module:
Step
1
2
3
4
5
194
What needs to be done?
Turn off the power supply of the
central unit.
Turn off the power supply of the
expansion unit in which you want to
replace the interface module.
Remove the interface module.
Insert the new interface module and
turn the power supply of the expansion
unit back on.
Switch the power supply of the central
unit back on and start the CPU.
How does the system react?
The connected expansion unit is turned off.
•
Both CPUs report the event in the diagnostic
•
buffer and with OB 86.
How does the system react?
The partner CPU switches to single mode.
•
–
–
–
CPU performs automatic LINK-UP and
•
UPDATE.
CPU changes to RUN and operates as the
•
standby CPU.
System Manual, 09/2007, A5E00267695-03
S7-400H