Operation In Fieldbus Systems; Communication Interfaces; Communication Via Uss - Siemens SINAMICS G120 Operating Instructions Manual

5.11

Operation in fieldbus systems

5.11.1

Communication interfaces

Fieldbus interfaces of the CU versions
The inverters are available in different versions for communication with higher-level controls
with the subsequently listed fieldbus interfaces:
● CU240E and CU240S for USS via RS485
● CU240S DP and CU240S DP-F for PROFIBUS DP
● CU240S DP and CU240S DP-F for PROFINET
5.11.2

Communication via USS

Universal serial interface (USS)
Using the USS protocol (protocol of the universal serial interface), users can set-up a serial
data connection between a higher-level master system and several slave systems (RS 485
interface). Master systems include programmable logic controllers (e.g. SIMATIC S7-200) or
PCs. The inverters are always slaves on the bus system.
The USS protocol allows you to implement automation tasks with cyclic telegram transfer
(fixed telegram length required) and visualization tasks. In this case, variable telegram
lengths are better since texts and parameter descriptions can be transferred in a single
telegram without the data being subdivided.
USS bus topology via RS 485
Communication networks with up to 31 inverters (slaves) connected to a control can be
established via the RS 485 interface. The topology must be configured as a line in which the
first and last devices are terminated with terminating resistors.
CU240S and CU240E Control Units, FW 3.2
Operating Instructions, 03/2009, A5E02440075B AA
– Control via PZD (process data channel)
– Parameterizing using PKW (parameter channel)
– Control in cyclic operation using telegrams 1, 20, 350, 352 and 999
– Control and parameterizing in cyclic operation using telegrams 353 and 354
– Parameterizing via acyclic communication
– Control in cyclic operation using telegrams 1, 20, 350, 352 and 999
– Control and parameterizing in cyclic operation using telegrams 353 and 354
– Parameterizing via acyclic communication
5.11 Operation in fieldbus systems
Functions
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