Hitachi WJ200 Series Quick Reference Manual page 32

CAUTION: Be sure to diode in between "P24" and "PLC" when connecting plural
inverters with digital input wiring in common.
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.
Short
Power ON
bar
P24
PLC
L
1
Short
Power OFF
bar
P24
PLC
L
1
Switch
OFF
P24
Short
PLC
bar
L
1
P24
PLC
L
Short
bar
1
Switch
OFF
Input
ON
Inserting
diode
In case of Source logic
Input
ON
30
Power ON
P24
PLC
L
Input
OFF
1
Power OFF
P24
PLC
L
1
Switch
OFF
P24
PLC
L
Input
OFF
1
P24
PLC
L
1
Switch
OFF