Siemens SIMATIC S7-400H Manual page 230

Modifying the System During Operation
11.2.4 PCS 7, Step 4: Loading New Hardware Configuration in the
Standby CPU
Initial situation
The fault-tolerant system is working in single mode.
Procedure
Load the compiled hardware configuration in the standby CPU that is in STOP
mode.
Notice
The user program and the connection configuration must not be overloaded in
single mode.
Result
The new hardware configuration of the standby CPU does not yet have an effect
on current operation.
11-10
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07