Siemens SIMATIC S7-CPs, Manual

Page: 18 / 60

3 Installation and Commissioning
B − 18
CP 443-1 for Industrial Ethernet / Manual Part B
Release 07/2010
C79000-G8976-C223 − 06
Note
When setting the ISO protocol, remember that MAC address set previously during
configuration is transferred by the CPU to the new CP module.
For information on replacing previous modules, please refer to the section
“Compatibility”.
Module replacement: Special feature of IP address assignment from a DHCP server
During configuration of the CP you can specify the IP configuration in the
properties dialog; one option is to obtain the IP address from a DHCP server.
Notice
When replacing modules, remember that the factory-set MAC address of the new
module is different from the previous module. When the factory-set 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 if you want to obtain the same IP address from the
DHCP server after replacing the module.
If you have configured a new MAC address instead of the factory-set MAC
address (generally the exception, for example when using the ISO protocol), the
DHCP server always receives the configured MAC address and the CP obtains
the same IP address as the replaced module.
3.3 Force mode
You can change the mode of the CP between RUN and STOP using the STEP 7 /
NCM S7 engineering software:
S
Switch from STOP to RUN:
The CP reads the configured and/or downloaded data into the work memory
and then changes to the RUN mode.
S Switch from RUN to STOP:
The CP changes to STOP. Established connections (ISO transport,
ISO-on-TCP, TCP, UDP connections) are terminated (transitional phase with
LED display “STOPPING”);
The reaction is as follows in STOP:
− The communications connections mentioned above are terminated;