BENSHAW RSi GM2 Series - RS-485 Communication Features; Communication Standards

RS-485 Communication Features
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GM2 Series VFD
RS-485 Communication Features
This section explains how to control the inverter with a PLC or a computer over a long distance
using the RS-485 communication features. To use the RS-485 communication features, connect the
communication cables and set the communication parameters in the inverter. Refer to the
communication protocols and parameters to configure and use the RS-485 communication
features.
Communication Standards
Following the RS-485 communication standards, GM2 inverters exchange data with a PLC and
computer. The RS-485 communication standards support the Multi-drop Link System and offer an
interface that is strongly resistant to noise. Please refer to the following table for details about the
communication standards.
Items
Standard
Communication method/
Transmission type
RS-485/Bus type, Multi-drop Link System
Inverter type name
GM2
Number of connected
inverters/ Transmission
distance
Maximum of 16 inverters / Maximum1,200 m (recommended distance:
within 700 m)
Recommended cable size
0.75mm², (18AWG), Shielded Type Twisted-Pair (STP) Wire
Installation type
Dedicated terminals (S+/S-) on the control terminal block
Connected to the RJ-45 connector (no 1 pin S+, no 8 pin S-)
Power supply
Supplied by the inverter-insulated power source from the inverter’s
internal circuit
Communication speed
1,200/2,400/4,800/9,600/19,200/38,400/57,600/115,200 bps
Control procedure
Asynchronous communications system
Communication system
Half duplex system
Character system
Modbus-RTU: Binary / LS INV 485: ASCII
Stop bit length
1-bit/2-bit
Frame error check
2 bytes
Parity check
None/Even/Odd