Communication Via Uss; Basic Settings For Communication - Siemens SINAMICS G120 Operating Instructions Manual

Configuring the fieldbus
7.7 Communication via RS485
7.7.2

Communication via USS

The USS protocol is a serial-data connection between one master and one or more slaves. A
master is, for example:
● A programmable logic controller (e.g. SIMATIC S7-200)
● A PC
The inverter is always a slave.
A maximum of 31 slaves is possible.
The maximum cable length is 100 m.
Information about how to connect the inverter to the USS fieldbus is provided in Section
Integrating inverters into a bus system via the RS485 interface (Page 157).
7.7.2.1

Basic settings for communication

Setting the address
You set the bus address of the inverter using the
address switches on the Control Unit, using
parameter p2021 or in STARTER.
Valid address range:
If you have specified a valid address using the
address switches, this address will always be the one
that takes effect, and parameter p2021 (factory
setting: 0) will not be able to be changed.
The positions of the address switches are described
in Section: Overview of the interfaces (Page 56).
Procedure
To change the bus address, proceed as follows:
1. Set the address using one of the subsequently listed options:
– using the address switches
– with an operator panel using p2021
– in STARTER using screen form "Control Unit/Communication/Fieldbus", or using the
2. Switch on the inverter power supply and, if being used, the 24 V supply
for the Control Unit.
3. Switch on the voltages again after all LEDs at the inverter have gone dark.
This means that you have changed the bus address.
158
1 ... 30
expert list with p2021
Converter with the CU250S-2 Control Unit (vector)
Operating Instructions, 06/2013, FW V4.6, A5E31759476B AB