Hitachi SJ2002 Series Instruction Manual page 153

The two diagrams below show input wiring circuits using an external supply. If using the
upper wiring diagram, be sure to use a diode with the external supply. This will prevent a
power supply contention in case the SR/SK switch is accidentally placed in the incorrect
position. Be sure to use the correct SR/SK switch position shown for each wiring
diagram.
Sinking Inputs, External Supply
SR/SK switch = SK position
Open collector outputs,
NPN transistors
Field device
+V
+
1
–
6
GND
Sourcing Inputs, External Supply
SR/SK switch = SR position
PNP transistor
sourcing outputs
Field device
1
6
+
–
24V
GND
* *
24V
+
–
Input
switches
Logic GND
* Note: If the external power supply GND is (optionally)
connected to [L], then install the above diode.
24V
+
–
Input
switches
Logic GND
SJ200
2
SJ200
2
PCS
SK
SR
SK
SR
1
Input
circuits
6
L
SJ200
2
PCS
SK
SR
SK
SR
1
Input
circuits
6
L
4–11
Inverter
24V
+
–
24V
+
–