Connecting The Bus Connector To A Module - Siemens simatic c7-621 Hardware Installation Manual

3.5.4

Connecting the Bus Connector to a Module

Connecting the
To connect the bus connector, follow the steps outlined below:
Bus Connector
1. Plug the bus connector into the module.
2. Screw the bus connector securely to the module.
3. If the bus connector with the order number 6ES7 ... is located at the start
Note
The bus connector 6ES7 972-0BA30-0XA0 does not have a terminating
resistor. You cannot plug in this bus connector at the start or end of a
segment.
Make sure that the stations on which the terminating resistor is located are
always turned on during startup and operation.
Figure 3-14
Removing the Bus
You can remove the bus connector with a LAN cable connected through at
Connector
any time from the PROFIBUS DP interface without interrupting the data
exchange on the bus.
Warning
!
Disturbance of data exchange on the bus is possible!
A bus segment must always be terminated at both ends. This is, for example,
not the case if the power supply to the last slave with a bus connector is not
turned on. Since the bus connector takes its power from the station, this
would make the terminating resistor ineffective.
Make sure that the stations on which the terminating resistor is activated, are
always turned on.
C7-621 / C7-621 AS-i Control Systems
C79000-G7076-C621-01
or end of a segment, you must activate the terminating resistor (switch
setting "ON") (see Figure 3-14 ).
Terminating
on
resistor on
off
Bus Connector (6ES7 ... ): Terminating Resistor Activated and
Deactivated
Configuring an MPI Network
Terminating resistor
on
off
off
3-19