Replacing A Module Without A Programming Device - Siemens SIMATIC S7-400 Operating Instructions Manual

Clear/reset module - effects
Following the memory reset, the CP retains the IP address. The CP is therefore immediately
ready for downloads using the IP address.
The configuration data is retained on the CPU.
The CPU in the S7 station does not recognize that the CP memory was reset. The CP
changes to the "Stopped (STOP) with error" state (see LEDs (Page 25)). The configuration
data must then be reloaded. You can also initiate this loading from the CPU by cycling power
(OFF > ON).
Reset to factory defaults - effects
After resetting to factory defaults, the CP always retains the factory set MAC address (as
supplied).
The IP address and the configuration data in the CP RAM are deleted. The configuration
data is retained on the CPU.
A language file (s7wmeldx.edb) loaded earlier for the diagnostics display via the Web server
is not deleted by a new firmware file.
6.6

Replacing a module without a programming device

General procedure
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.
Module replacement: Special feature of IP address assignment from a DHCP server
When configuring in the Properties dialog, you can specify the IP configuration for the CP.
One option here is that the CP obtains 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 factoryset MAC address of the new module is
sent to the DHCP server, this will return either 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 if you always want
to obtain the same IP address from the DHCP server after replacing the module.
CP 443-1 OPC UA
Operating Instructions, 01/2017, C79000-G8976-C427-02
6.6 Replacing a module without a programming device
Diagnostics and maintenance
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