Connecting The Inverter To Modbus - Hitachi WJ200 Series Instruction Manual

Connecting the Inverter to ModBus

Modbus connector is in control terminal block as below. Note that RJ45 connector
(RS-422) is used for external operator only.
SN 7 6
SP EO EA
RS-485
(Modbus)
External device
-
Terminate Network Wiring - The RS-485 wiring must be terminated at each physical
end to suppress electrical reflections and help decrease transmission errors. WJ200 has
a built-in 200
Ω resistor activated by a dip switch.
the characteristic impedance of the network cable. The diagram above shows a network
with the needed termination resistor at each end.
Dip switch for termination resistor
5 4 3 2 1
H O OI L AM
(Master)
+
SP SN
200Ω
WJ200 (No.1)
L PLC P24
CM2 12 11
SP SN
WJ200 (No.2) WJ200 (No.3)
Select termination resistors that match
USB
RS-422
(Operator)
SP SN SP SN
WJ200 (No.n)
B−3