System modifications during operation
17.5 Adding components in STEP 7
S7-400H
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System Manual, 03/2012, A5E00267695-11
17.5.4
STEP 7, step 4: Stopping the reserve CPU
Starting situation
The fault-tolerant system is operating in redundant system mode.
Procedure
1.
In SIMATIC Manager, select a CPU of the fault-tolerant system, then choose "PLC >
Operating Mode" from the menu.
2.
In the "Operating Mode" dialog box, select the reserve CPU, then click "Stop".
Result
The reserve CPU switches to STOP mode, the master CPU remains in RUN mode, the fault-
tolerant system works in single mode. The one-sided I/O of the reserve CPU is no longer
addressed. OB 70 (I/O redundancy loss) is not called due to the higher-priority CPU
redundancy loss (OB72).
17.5.5
STEP 7, step 5: Loading a new hardware configuration in the reserve CPU
Starting situation
The fault-tolerant system is operating in single mode.
Procedure
Load the compiled hardware configuration in the reserve CPU that is in STOP mode.
NOTICE
The user program and connection configuration cannot be downloaded in single mode.
Result
The new hardware configuration of the reserve CPU does not yet have an effect on ongoing
operation.