Hitachi WJ200 Series Instruction Manual page 217

4−14
The two diagrams below show input wiring circuits using an external supply. If using
the "Sinking Inputs, External Supply" in below wiring diagram, be sure to remove the
short bar, and use a diode (*) with the external supply. This will prevent a power
supply contention in case the short bar is accidentally placed in the incorrect position.
For the "Sourcing Inputs, External Supply", please connect the short bar as drawn in
the diagram below.
Sinking Inputs, External Supply
Short bar = Removed
Field device
+
24V
-
Open collector outputs,
NPN transistors
Sourcing Inputs, External Supply
Short bar = [PLC] – [L]
PNP transistor
sourcing outputs
Field device
+
24V
-
*
24V
+
-
GND
1
7
Input switches
* Note: If the external power supply to GND is (optionally)
connected to [L], then install the above diode.
1
7
Input switches
GND
P24
*
Input common
PLC
Logic GND
L
1
Input
circuits
7
Short bar
P24
24V
Input common
+
PLC
-
L
1
Input
circuits
7
WJ200
24V
+
-
WJ200
24V
+
-