Siemens SIMATIC S7-400H Manual page 246

Modifying the System During Operation
11.4.2 STEP 7, Step 2: Offline Modification of the Hardware
Configuration
Initial situation
The fault-tolerant system is working in redundant system mode. The modules
added will not yet be addressed.
Procedure
1. Perform all the modifications to the hardware configuration relating to the added
hardware offline.
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.
Configuring connections
Connections from or to newly added CPs must be configured on both connection
partners after modification of the hardware configuration is completed.
11.4.3 STEP 7, Step 3: Expanding and Loading Organization Blocks
Initial situation
The fault-tolerant system is working in redundant system mode.
Procedure
1. Make sure that the interrupt OBs 4x, 82, 83, 85, 86 and 122 react in the desired
way to interrupts from the newly added components.
2. Load the modified OBs and the program segments affected by these into the
PLC.
Result
The fault-tolerant system is working in redundant system mode.
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Automation System S7-400H Fault-tolerant Systems
A5E00068197-07