Communication Via Rs485; Integrating Inverters Into A Bus System Via The Rs485 Interface - Siemens SINAMICS G120 Operating Instructions Manual

7.7

Communication via RS485

7.7.1

Integrating inverters into a bus system via the RS485 interface

Connecting to a network via RS485
Connect the inverter to your fieldbus via the RS485 interface. Position and assignment of the
RS485 interface can be found in Section Overview of the interfaces (Page 56). This
connector has short-circuit proof, isolated pins.
Figure 7-9
You must switch-in the bus-terminating resistor for the first and last nodes. The position of
the bus-terminating resistor can be found in Section Overview of the interfaces (Page 56).
Note
During bus operation the first and last bus subscriber must be constantly supplied with power
as otherwise the communication with the other subscribers is broken.
With the exception of the first or last slave, when required you can remove slaves from the
bus. To do this, withdraw the bus connector. When doing this, communication to the other
nodes (stations) is not interrupted.
Communication with the controller, even when the supply voltage on the Power Module is
switched off
You must supply the Control Unit with 24 V DC at terminals 31 and 32 if you wish to maintain
communication with the control system when the line voltage is switched off.
In the case of short interruptions of the 24 V voltage supply, the inverter may report a fault
without communications with the controller being interrupted.
Converter with the CU250S-2 Control Unit (vector)
Operating Instructions, 06/2013, FW V4.6, A5E31759476B AB
Communication network via RS485
Configuring the fieldbus
7.7 Communication via RS485
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