Network Settings; Reserved Mac Address; Transmission Properties Of The Ethernet And Rna Interfaces - Siemens SIMATIC NET S7-400 Manual

Configuration and operation

6.4 Network settings

6.4 Network settings
6.4.1

Reserved MAC address

NOTICE
Do not use the MAC address
Internally, the CP uses the following reserved MAC address:
00-1B-1B-31-4D-00
Do not use this MAC address for communications partners of the CP, otherwise no
communication is possible with the communications partner.
6.4.2

Transmission properties of the Ethernet and RNA interfaces

The common transmission characteristics of the two interfaces are described below.
The configuration of the network settings "Transmission medium / duplex" is made for the
Ethernet interfaces in the properties of the port in STEP 7/HW Config:
Row "X1P1": Port properties of the Ethernet interface
Automatic setting or individual network settings
As default, the CP is configured for automatic detection (autosensing) for both interfaces.
The settings for the RNA interface are fixed.
If necessary, you can change the settings for the Ethernet interface.
Note
In normal situations, the basic setting ensures troublefree communication. You should only
change this in exceptional situations.
Ethernet interface:
If you create a manual configuration for the CP and disable the autonegotiation option, the
automatic negotiation of the network settings (autonegotiation) is no longer effective. If, on
the other hand, the communications partner works with autonegotiation, it is not certain that
error-free communication will be established.
Autocrossing mechanism
With the integrated autocrossing mechanism, it is possible to use a standard cable to
connect the PC/PG. A crossover cable is not necessary.
42
CP 443-1 RNA
Manual, 03/2019, C79000-G8976-C299-04