Siemens NCM S7 Manual page 71

Relocating the CP in the Hardware Configuration
If you are using communication services with configured connections, the
connection IDs also identify the slot of the CP. If you "drag" a CP you have already
configured to a different slot, note the following:
Notice
If you drag the CP to a different slot, the data of the connection configuration are
automatically updated. The data of the connection configuration must, however, be
downloaded again!
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SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
Installing and Starting the Ethernet CP with STEP 7
71