Siemens SIMATIC S7-400H - STEP 7, Step III: Stopping the Standby CPU

Modifying the System During Operation
11-35
Automation System S7-400H Fault-tolerant Systems
A5E00068197-07
11.5.3 STEP 7, Step III: Stopping the Standby CPU
Initial situation
The fault-tolerant system is working in redundant system mode. The user program
will no longer attempt to access the hardware to be removed.
Procedure
1. In SIMATIC Manager, select a CPU of the fault-tolerant system, and choose the
PLC > Operating Mode menu command.
2. In the Operating Mode dialog box, select the standby CPU and click the Stop
button.
Result
The standby CPU switches to STOP mode, the master CPU remains in RUN
mode, the fault-tolerant system works in single mode. One-way I/O of the standby
CPU are no longer addressed.
11.5.4 STEP 7, Step IV: 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.