Configuration, program blocks
4.2 Network settings
4.2
Network settings
4.2.1
Fast Ethernet
Transmission speed/directionality of the interface
• CM 1542-1 (6GK7542-1AX00-0XE0)
Only "Automatic" for automatic detection (autosensing) and "100 Mbps full duplex" can be
set for the transmission speed/directionality of the connection.
In normal situations, the basic setting ensures troublefree communication.
• CM 1542-1 (6GK7542-1AX10-0XE0)
In PROFINET operation, the CM only supports "100 Mbps full duplex".
Auto-crossover mechanism
With the integrated auto-crossover mechanism, it is possible to use a standard cable to
connect the PC/PG. A crossover cable is not necessary.
To connect a switch that does not support auto-crossover, use a crossover cable.
4.3
IP configuration
4.3.1
Restart after detection of a duplicate IP address in the network
To save you timeconsuming troubleshooting in the network, during startup the CM detects
double addressing in the network.
Behavior when the CM starts up
If double addressing is detected when the CM starts up, the CM changes to RUN and cannot
be reached via the Ethernet interface. The ERROR LED flashes.
4.3.2
Remove retentive storage of the IP address if there are duplicate addresses
The IP address and the device name of the CM 1542-1 remain installed retentively:
If, for example during startup, the CM detects a duplicate address in another network, the CM
is not connected to the network. The CM changes to RUN and cannot be reached via the
Ethernet interface.
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Operating Instructions, 04/2023, C79000-G8976-C355-05
SIMATIC CM 1542-1