Diagnostics and upkeep
5.5 Replacing a module without a programming device
CP 1543-1
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Operating Instructions, 12/2019, C79000-G8976-C289-08
5.5
Replacing a module without a programming device
Configuration data when swapping modules
The configuration data of the CP is stored on the CPU. This makes it possible to replace this
module with a module of the same type (identical article number) without a PG.
Note
Configured MAC address is adopted
When setting the ISO protocol, remember that MAC address set previously during
configuration is transferred by the CPU to the new CP module.
Swapping modules for address reference via DHCP (IPv4)
One option in the IP configuration of the CP is to obtain the IP address from a DHCP server.
Note
Recommendation: Configuring a client ID
When replacing modules, remember that the factoryset MAC address of the new module is
different from the previous module.
When the factory default MAC address of the new module is sent to the DHCP server, the
DHCP server returns a different or no IP address.
Ideally, you should therefore configure IP as follows:
•
Always configure a client ID and configure your DHCP server accordingly. This ensures
that the CP always receives the same IP address from the DHCP server after swapping a
module.
If you have configured a new MAC address instead of the MAC address set in the factory,
the configured MAC address will always be transferred to the DHCP server. In this case, the
new CP also has the same IP address as the previous module.
