Omron NXR Series User Manual page 72

5 Installation and Wiring
Precautions for Correct Use
If you make the following setting to pin 2 and pin 4 of the port for the Digital I/O Variable Hub
and connect the Hub with external devices, use the external devices without protective diodes
in the locations shown in the following figure.
• Pin 4: Output, Pin 2: Input
• Pin 4: Input, Pin 2: Output
If the connected external devices have protective diodes, change them to those with built-in re-
verse current prevention diodes as shown in the following figure, or externally install reverse
current prevention diodes.
1
I/O connector
IO-Link Master Unit
L
Internal
circuits
Connected external device
L
Internal
circuits
Connected external device
If the connected external devices have protective diodes, reverse current flows due to a differ-
ence between the Unit/input power supply and the output power supply as shown in the figure
below, which may result in failure or malfunction of the product or connected external devices.
5-12
U/IN P+
2
OUT P+
3
U/IN P-/OUT P-
4
C/Q
Protective diode
Built-in reverse
current prevention
diode
Protective diode
External reverse
current prevention
diode
IO-Link connector
1
4
2
3
IO white
2 I/O connector
V brown
3
Pin 4: Input
1
Pin 2: Output
4
IO black
G blue
IO white
2
I/O connector
V brown
3 Pin 4: Output
Pin 2: Input
1
4
IO black
G blue
Digital I/O Variable Hub
NXR-series IO-Link I/O Hub User's Manual (W620)