Communication Via Rs485; Integrating Inverters Into A Bus System Via The Rs485 Interface - Siemens SINAMICS G120 CU230P-2 HVAC Operating Instructions Manual

Configuring the fieldbus

6.2 Communication via RS485

6.2 Communication via RS485
6.2.1

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 Interfaces, connectors, switches, control terminals,
LEDs on the CU (Page 46). This connector has short-circuit proof, isolated pins.
Figure 6-4
You must switch-in the bus terminating resistor for the first and last participants. The position
of the bus terminating resistor can be found in section Interfaces, connectors, switches,
control terminals, LEDs on the CU (Page 46).
You can disconnect one or more slaves from the bus (by unplugging the bus connector)
without interrupting the communication for the other stations, but not the first or last.
NOTICE
When the bus is operating, the first and last bus station must be continuously connected to
the supply.
Note
Communication with the controller, even when the supply voltage on the Power Module is
switched off
You will have to supply the Control Unit with 24 V DC on terminals 31 and 32 if you require
communication to take place with the controller when the line voltage is switched off.
118
Communication network via RS485
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD