Siemens SIMATIC S7 System Manual page 133

PROFINET device naming and addressing in STEP 7
All PROFINET devices must have a Device Name and an IP Address. Use STEP 7 to define
the Device Names and to configure the IP addresses. Device names are downloaded to the
IO devices using PROFINET DCP (Discovery and Configuration Protocol).
PROFINET address assignment at system start-up
The controller broadcasts the names of the devices to the network, and the devices respond
with their MAC addresses. The controller then assigns an IP address to the device using
PROFINET DCP protocol:
● If the MAC address has a configured IP address, then the station performs start-up.
● If the MAC address does not have a configured IP address, STEP 7 assigns the address
● If there is a problem with this process, a station error occurs and no start-up takes place.
S7-1200 Programmable controller
System Manual, 11/2011, A5E02486680-05
that is configured in the project, and the station then performs start-up.
This situation causes the configurable time-out value to be exceeded.
98BDevice configuration
5.6 Configuring the CPU for communication
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