Siemens SIMATIC NET S7-300 Manual page 75

IP Configuration Tab
In this tab, you can decide the route and the method with which the IP address of
the local S7 station is obtained and assigned.
V 5.2.1
With the options available here, it is also possible to assign IP addresses
dynamically outside the STEP 7 configuration.
Table 3-2 Options in the "IP Configuration" Tab
Option
S
Set IP address in the
"Properties - Ethernet
Interface" dialog
S
Obtain an IP address from a
DHCP server
S
Set IP address in the user
program
S
Set IP address using a
different method
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
This option is the default.
It means that the IP address is set during the networking of the
Ethernet CP. The IP address of the CP is therefore fixed in the
configuration.
You must select this option if you want to configure specified
connections.
If you select this option, the IP address is obtained from a DHCP
server when the S7 station starts up.
The DHCP server is informed of the MAC address of the CP or the
client ID that you can enter here.
Requirement / Restriction:
If you select this option, it is initially not possible to create a fully
specified connection in the STEP 7 project because the local IP
address is not known.
You must therefore select "unspecified" with passive connection
establishment as the connection type.
Please not the following:
If the connections are configured over the interface in the user
program, you must use the option "Set IP address in the user
program" as described below. This also applied if the IP address is
obtained from a DHCP server.
With this option, you specify that the IP address is set over a user
program interface (function block IP_CONFIG). This allows the IP
address to be supplied dynamically during operation.
In this situation, communication connections are created only over
the user program interface; configuring connections using STEP 7 is
not possible (relates to connections over IP: TCP, ISO-on-TCP, UDP).
This setting does not preclude the IP address being obtained from a
DHCP server. It is possible for the user program to instruct the
module to obtain an IP address in this way.
Further information:
Read the section "Programmed Communication Connections" and
refer to the example in the appendix of the manual.
With this option, you specify that the IP address is set by other
services outside STEP 7.
In this situation, configuring connections using STEP 7 is not possible
(relates to connections over IP: TCP, ISO-on-TCP, UDP ).
3 Operating the Ethernet CP with
Meaning / Effect
A -75