Omron MX2 - Connecting the Inverter to Modbus; Terminate Network Wiring

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Connecting the Inverter to ModBus Section B-2
B-2 Connecting the Inverter to ModBus
Modbus connector is in control terminal block as below. Note that RJ45 con-
nector (RS-422) is used for external operator only.
Terminate Network Wiring – The RS-485 wiring must be terminated at each
physical end to suppress electrical reflections and help decrease transmission
errors. MX2 has a built-in 200 resistor activated by a dip switch. Select termi-
nation resistors that match the characteristic impedance of the network cable.
The diagram above shows a network with the needed termination resistor at
each end.
PLC P241 L3 25 46
SN
7
12 11 AM CM2OI LH OEA
SP
EO
RS-485
(Modbus)
SP SN
SP SN SP SN SP SN
External device
(Master)
+-
MX2 (No.2) MX2 (No.3) MX2 (No.n)
MX2 (No.1)
200 Ω
RS-422
(Operator)
USB
Dip switch for termination resistor