Wiring For Rs485 Communications Terminals - Omron RX Series User Manual

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Wiring for RS485 Communications Terminals

The 3G3RX-V1 Series has an RS485 communications capability that enables the inverter to
communicate with an external controller from its RS485 communications terminal block on the control
terminal block PCB.
For the communications protocol, the inverter supports the Modbus communication and the ASCII
format.
This section describes the wiring procedure for the RS485 communications terminal block and the
installation of the terminating resistor.
Wiring for RS485 Communications Terminal Block
RS+ RS− RP RS−
TM2
Communication terminal block TM2
Wire size and tightening torque
Tightening
Screw size
torque [N·m]
M2 0.22 to 0.25
High-function General-purpose Inverter 3G3RX-V1 User's Manual (I578-E1)
Terminal
symbol
RS+
Control terminal
block
Control terminal
block board
RS–
RP
RS–
Wire type
0.14 to 1.5
Solid wire
(If two equal-sized wires are connected to one pole: 0.14 to
0.5)
0.14 to 1.0
Stranded wire
(If two equal-sized wires are connected to one pole: 0.14 to
0.2)
0.25 to 0.5
Stranded wire with
pin terminal
(Example: PC-1.25 F-7 from JST Mfg. Co., Ltd.)
Terminal name
RS485
communications
Positive-side send/receive terminal
send/receive
signal for RS485 communications.
terminal, positive
side
RS485
communications
Negative-side send/receive terminal
send/receive
signal for RS485 communications.
terminal, negative
side
Terminating Resistor The RP terminal is used to enable the
built-in Terminating Resistor (100 Ω).
enable terminal
Connect the negative-side RS485
RS485
communications send/receive
communications
terminal (for Termination Resistor
send/receive
connection) with the terminal RP to
terminal, negative
side (for Terminating enable the built-in Terminating
Resistor.
Resistor connection)
Wire size [mm
2 Design
Function
2
]
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