Siemens SIMATIC S7-400H Manual page 253

11.5.1 STEP 7, Step I: Offline Modification of the Hardware
Configuration
Initial situation
The fault-tolerant system is working in redundant system mode.
Procedure
1. Perform offline all the modifications to the hardware configuration relating to the
hardware to be removed.
2. Compile the new hardware configuration, but do not load it into the PLC just
yet.
Result
The modified hardware configuration is in the PG. The PLC continues to work with
the old configuration in redundant system mode.
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
Modifying the System During Operation
11-33