Unit name Function
I/O Power Supply Con-
nection Unit
This NX Unit is used when there are not enough I/O power supply terminals for the
connected external devices that are connected to NX Units such as Digital I/O Units
and Analog I/O Units.
NX Unit
Example of NPN type
Not enough I/O
power supply
terminals
I/O Power Supply
Connection Unit
I/O power
supply
Unit
power
supply
Internal power
supply circuit
IOV
DC Input Unit
(NPN type)
Two-wire sensor
(e.g., limit switch)
A1
A8
B1
B8
A1
A8
B1
B8
I/O Power Supply
Connection Unit
(16 IOV terminals)
A1
A8
B1
B8
Three-wire sensor
with NPN output*
(e.g., photoelectric
sensor or proximity
sensor)
Brown
(White)
Blue (Black)
Black (White)
Brown (Red)
Blue (Black)
I/O Power Supply
Connection Unit
(16 IOG terminals)
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOV
IOG
IOG
IOG
IOG
IOG
IOG
IOG
IOG
IOG
IOG
IOG
IOG
IOG
IOG
IOG
IOG
1
9
7
5
3
1
3
11
15
0
8
6
4
2
12
10
14
I/O power supply is not separated
in
I/O Power Supply Connection Unit
Additional I/O
Power Supply
Unit
I/O power
supply
NX-series
CPU Unit
*
* Wire colors have been changed according to revisions in the JIS standards for pho-
toelectric and proximity sensors. The colors in parentheses are the wire colors prior to
the revisions.
4 Installation and Wiring
4-14
NX-series System Units User's Manual (W523)