Siemens SINAMICS G120 CU240B-2 Operating Instructions Manual page 7

6.3.4 Acyclic communication...............................................................................................................123
6.3.4.1 Acyclic communication over PROFIBUS DP (DP V1) ...............................................................123
6.3.5 STEP 7 program examples........................................................................................................124
6.3.5.1 STEP 7 program example for cyclic communication .................................................................124
6.3.5.2 STEP 7 program example for acyclic communication ...............................................................126
6.4 Communication via RS485 ........................................................................................................130
6.4.1 Integrating inverters into a bus system via the RS485 interface ...............................................130
6.4.2 Communication via USS ............................................................................................................131
6.4.2.1 General information about communication with USS via RS485 ..............................................131
6.4.2.2 Structure of a USS telegram ......................................................................................................133
6.4.2.3 User data range of the USS telegram........................................................................................135
6.4.2.4 Data structure of the USS parameter channel...........................................................................135
6.4.2.5 USS read request ......................................................................................................................140
6.4.2.6 USS write job .............................................................................................................................140
6.4.2.7 USS process data channel (PZD)..............................................................................................141
6.4.2.8 Telegram monitoring ..................................................................................................................142
6.4.3 Communication over Modbus RTU............................................................................................144
6.4.3.1 Parameters for Modbus communication settings.......................................................................144
6.4.3.2 Modbus RTU telegram...............................................................................................................146
6.4.3.3 Baud rates and mapping tables .................................................................................................147
6.4.3.4 Write and read access via FC 3 and FC 6.................................................................................150
6.4.3.5 Communication procedure.........................................................................................................152
7 Functions ............................................................................................................................................... 155
7.1 Overview of the inverter functions..............................................................................................155
7.2 Inverter control ...........................................................................................................................157
7.3
Command sources.....................................................................................................................158
7.4 Setpoint sources ........................................................................................................................159
7.4.1 Selecting the setpoint source.....................................................................................................159
7.4.2 Analog input as setpoint source.................................................................................................160
7.4.3 Motorized potentiometer as setpoint source..............................................................................160
7.4.4 Fixed speed as setpoint source .................................................................................................163
7.4.5 Running the motor in jog mode (JOG function) .........................................................................165
7.4.6 Specifying the motor speed via the fieldbus ..............................................................................166
7.5 Setpoint calculation....................................................................................................................166
7.5.1 Minimum speed and maximum speed .......................................................................................166
7.5.2 Ramp-function generator ...........................................................................................................167
7.6 Motor control ..............................................................................................................................168
7.6.1 V/f control ...................................................................................................................................169
7.6.1.1 V/f control with linear characteristic ...........................................................................................170
7.6.1.2 Additional characteristics for the V/f control...............................................................................171
7.6.1.3 Optimizing with a high break loose torque and brief overload...................................................172
7.6.2 Vector control .............................................................................................................................173
7.6.2.1 Properties of vector control ........................................................................................................173
7.6.2.2 Commissioning vector control....................................................................................................173
7.6.2.3 Torque control ............................................................................................................................174
7.7 Protection functions ...................................................................................................................175
7.7.1 Inverter temperature monitoring.................................................................................................175
7.7.2 Motor temperature monitoring using a temperature sensor ......................................................176
7.7.3 Protecting the motor by calculating the motor temperature.......................................................178
7.7.4 Overcurrent protection ...............................................................................................................178
7.7.5 Limiting the maximum DC link voltage.......................................................................................179
Inverter with CU240B-2 and CU240E-2 Control Units
Operating Instructions, 07/2010, FW 4.3.2, A5E02299792B AA
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