Specifications

Basic Wiring
Sink input specifications
Source input specifications
2-wire with 2-switch AND connection
2-wire with 2-switch OR connection
2-wire
2-wire
Example: Power supply is 24VDC
Internal voltage drop in switch is 4V
Example: Load impedance is 3kΩ
Leakage current from switch is 1mA
Connection Examples for AND (Series) and OR (Parallel)
Examples of Connection to PLC
When two switches are
connected in series, a load
may malfunction because
the load voltage will de-
cline when in the ON state.
The indicator lights will light
up if both of the switches
are in the ON state.
PLC internal circuit
COM
Switch
Input
Black
[White]
Brown
[Red]
Blue
[Black]
PLC internal circuit
COM
Switch
Input
Brown
[Red]
Blue
[Black]
PLC internal circuit
Switch
Input
COM
Blue
[Black]
Brown
[Red]
PLC internal circuit
COM
Switch
Input
Black
[White]
Brown
[Red]
Blue
[Black]
Switch 1
Switch 2
Load
Blue
[Black]
Brown
[Red]
Blue
[Black]
Brown
[Red]
Switch 1
Switch 2
Load
Brown
[Red]
Blue
[Black]
Brown
[Red]
Blue
[Black]
3-wire
OR connection for NPN output
Switch 1
Switch 2
Load
Switch 1
Brown
[Red]
Switch 2
Black
[White]
Blue
[Black]
Relay
Relay
Black
[White]
Load
Relay
contact
AND connection for NPN output
(using relays)
Switch 1
Brown
[Red]
Switch 2
Load
Brown
[Red]
AND connection for NPN output
(performed with switches only)
The indicator lights will light up when
both switches are turned ON.
<Reed switch>
3-wire, NPN
3-wire, PNP
Brown [Red]
Blue
[Black]
Blue
[Black]
Black
[White]
Black
[White]
Blue
[Black]
Brown
[Red]
Blue
[Black]
Black
[White]
Blue
[Black]
Black
[White]
Brown
[Red]
Because there is no current
leakage, the load voltage will
not increase when turned
OFF. However, depending
on the number of switches in
the ON state, the indicator
lights may sometimes grow
dim or not light up because
of the dispersion and reduc-
tion of the current flowing to
the switches.
Load voltage at ON = – x 2 pcs.
= 24V – 4V x 2 pcs.
= 16V
Power supply
voltage
Leakage
current
Load
impedance
Load voltage at OFF = x 2 pcs. x
= 1mA x 2 pcs. x 3kΩ
= 6V
Internal
voltage
drop
Solid state 3-wire, NPN
2-wire
Solid state 3-wire, PNP
(Power supplies for switch and load
are separate.)
Blue
[Black]
Load
Brown
[Red]
Black
[White]
Main circuit
of switch
Brown
[Red]
Load
Blue
[Black]
Black
[White]
Load
Blue
[Black]
Brown
[Red]
Load
Blue
[Black]
Brown
[Red]
Load
Brown
[Red]
Blue
[Black]
Black
[White]
2-wire
Indicator
light,
protection
circuit,
etc.
Brown
[Red]
Blue
[Black]
Load
<Reed switch>
Brown
[Red]
Blue
[Black]
Load
<Solid state>
Indicator
light,
protection
circuit,
etc.
Main circuit
of switch
Main circuit
of switch
Main circuit
of switch
Main circuit
of switch
The connection method will vary
depending on the applicable PLC
input specifications.
<Solid state>
When two switches
are connected in
parallel, a malfunc-
tion may occur be-
cause the load volt-
age will increase
when in the OFF
state.
Series CU
Auto Switch Connections and Examples
8