Connecting The Inverter To Modbus; Terminate Network Wiring - Omron 3G3MX2 User Manual

Connecting the Inverter to ModBus

B-2 Connecting the Inverter to ModBus
296
Modbus connector is in control terminal block as below. Note that RJ45 con-
nector (RS-422) is used for external operator only.
Dip switch for termination resistor
SN 7 6 5 4 3
SP EO EA H O OI
RS-485
(Modbus)
External device
(Master)
- +
SP
MX2 (No.1)
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.
2 1 L PLC P24
L AM CM2 12 11
SN
SP SN
MX2 (No.2) MX2 (No.3)
200 Ω
Section B-2
USB
RS-422
(Operator)
SP SN SP SN
MX2 (No.n)