Siemens SIMATIC S7-400H - Failure and Replacement of a Redundant PROFIBUS DP Interface Module

Failure and replacement of components during operation
16.3 Failure and replacement of components of the distributed I/Os
S7-400H
System Manual, 03/2012, A5E00267695-11
277
Procedure
Proceed as follows to replace a PROFIBUS DP master:
Step What has to be done? How does the system react?
1 Turn off the power supply of the central
rack.
The fault-tolerant system switches to single
mode.
2 Unplug the Profibus DP cable of the
affected DP master module.
–
3 Replace the module. –
4 Plug the Profibus DP back in. –
5 Turn on the power supply of the central
rack.
 The CPU performs an automatic LINK-
UP and UPDATE.
 The CPU changes to RUN and operates
as the reserve CPU.
16.3.2 Failure and replacement of a redundant PROFIBUS DP interface module
Starting situation
Failure How does the system react?
The S7-400H is in redundant system mode and a
PROFIBUS DP interface module (IM 153–2, IM
157) fails.
Both CPUs report the event in the diagnostic
buffer and via OB 70.
Replacement procedure
Proceed as follows to replace the PROFIBUS DP interface module:
Step What has to be done? How does the system react?
1 Turn off the supply for the affected DP
interface module.
–
2 Remove the bus connector. –
3 Insert the new PROFIBUS DP interface
module and turn the power supply back on.
–
4 Plug the bus connector back in.
 The CPUs process the I/O redundancy
error OB 70 (outgoing event)
synchronized with each other.
 Redundant access to the station by the
system is now possible again.