Wiring
6.10 RJ45 Ethernet connector
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
6-17
The figure below shows the switch settings of a bus connector:
Terminating resistor enabled
Terminating resistor disabled
on
off
On
Of
f
on
off
On
Of
f
Removing the bus connectors
With a looped-through bus cable, you can always unplug the bus connector from the
PROFIBUS-DP interface without interrupting data traffic on the bus.
Possible data traffic errors
Warning
Data traffic error might occur on the bus!
A bus segment always has to be terminated at both ends with a terminating resistor. This is
not the case if the last slave with bus connector is off power, for example. The bus connector
draws its power from the station, and the terminating resistor is thus disabled. Please make
sure that power is always supplied to stations on which the terminating resistor is active.
6.10
RJ45 Ethernet connector
This is an 8-pin connector with a design in accordance with ISO/IEC 8877:1992. This
connector type is recommended to IEEE 802.3 for 10BASE-T and 100BASE-TX interfaces.
The RJ45 connector is currently only available in standard patch cable lengths (TP cord).
Reference
For detailed information on RJ45 connectors, refer to the SIMATIC NET Twisted-Pair and
Fiber Optic Networks (6GK1970-1BA10-0AA0) manual, available on the Internet at