Siemens SIMATIC S7 System Manual page 215

Use the following procedure to assign an IP address online:
1. In the "Project tree," verify that
no IP address is assigned to the
CPU, with the following menu
selections:
 "Online access"
 <Adapter card for the network
 "Update accessible devices"
2. In the "Project tree," make the
following menu selections:
 "Online access"
 <Adapter card for the network
 "Update accessible devices"
 <device address>
 "Online & diagnostics"
S7-1200 Programmable controller
System Manual, 11/2009, A5E02486680-02
in which the device is
located>
in which the device is
located>
7.2 Communication with a programming device
PROFINET
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