Siemens SIMATIC S7-400H - STEP 7, Step VII: Modification of Hardware

Modifying the System During Operation
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Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
Response if monitoring times are exceeded
If one of the monitored times exceeds the maximum value configured the update is
interrupted. The fault-tolerant system remains in single mode with the previous
master CPU and in certain conditions attempts to perform the link-up and update
later. For more details refer to Section 6.3.
11.5.7 STEP 7, Step VII: Modification of Hardware
Initial situation
The fault-tolerant system works with the new hardware configuration in redundant
system mode.
Procedure
1. Disconnect all the sensors and actuators from the components to be removed.
2. Remove the desired components from the system.
– Unplug central modules from the rack.
– Unplug modules from modular DP stations
– Remove DP stations from DP master systems.
Notice
With switched I/O: Complete all changes on one line of the redundant DP master
system first before making changes to the second line.
Result
Unplugging modules that have been removed from the configuration has no effect
on the user program. The same applies to the removal of DP stations.
The fault-tolerant system continues to work in redundant system mode.