Hitachi WJ200 Series Quick Reference Manual page 36

CAUTION: When using with plural inverters connected, connect a diode between sink
logic: P24 and PLC and between source logic: L and PLC.
The power to the inverter control part can be supplied externally as shown below. Except
driving motor, it is possible read and write the parameters by keypad and via
communication even the drive itself is not powered.
By having ability inverter doesn't block the current flowing into itself when it is not
powered. This may cause the closed circuit when two or more inverters are connected to
common I/O wiring as shown below to result in unexpected turning the on the input. To
avoid this closed circuit, please put the diode (rated:50V/0.1A) in the path as described
below.
Jumper
wire
P24
PLC
L
1
Jumper
wire
P24
PLC
L
1
Switch
OFF
P24
Jumper
PLC
wire
L
1
Jumper
wire
P24
PLC
L
1
Switch
OFF
In case of Sink logic
Power ON
Input
ON
Inserting
diode
Power OFF
In case of Source logic
Input
ON
Inserting
diode
30
Power ON
P24
PLC
L
Input
1
Power OFF
P24
PLC
L
1
Switch
OFF
P24
PLC
L
Input
OFF
1
P24
PLC
L
1
Switch
OFF
OFF