Siemens SINAMICS G120 Original Instructions

Configuring the fieldbus
7.6 Communication via RS485
Inverter with CU230P-2 Control Units
Operating Instructions, 11/2013, FW V4.6.6, A5E02430659B AG
161
7.6.3
Communication over Modbus RTU
Overview of communication using Modbus
The Modbus protocol is a communication protocol with linear topology based on a
master/slave architecture.
Modbus offers three transmission modes:
●
Modbus ASCII
Data in ASCII code. The data throughput is lower compared to RTU.
●
Modbus RTU (RTU: Remote Terminal Unit)
Data in binary format. The data throughput is greater than in ASCII code.
●
Modbus TCP
Data as TCP/IP packets. TCP port 502 is reserved for Modbus TCP. Modbus TCP is
currently undergoing definition as a standard (IEC PAS 62030 (pre-standard)).
The Control Unit supports Modbus RTU as a slave with even parity.
Communication settings
● Communication using Modbus RTU takes place over the RS485 interface with a
maximum of 247 slaves.
● The maximum cable length is 100 m.
● Two 100 kΩ resistors are provided to polarize the receive and send cables.
Note
It is not permitted to change over the units
The "
Unit changeover (Page 267)" function is not permissible with this bus system!

Siemens SINAMICS G120 Specifications

General

Power Range	0.37 kW to 250 kW
Output Voltage	0 V to Input Voltage
Frequency Range	0 Hz to 650 Hz
Enclosure Rating	IP20, IP21, IP55
Control Modes	V/f control, vector control, servo control
Protection Features	Overvoltage, undervoltage, short circuit
Communication Interfaces	PROFIBUS, PROFINET, Modbus RTU
Operating Temperature	-10°C to +50°C
Cooling Method	Air cooling
Input Voltage	200 V to 240 V, 380 V to 480 V, 500 V to 690 V