Wiring Example 2 (Analog input range: Current)
24 VDC
A1
B1
A8
B8
IOV
IOG
IOV
IOG
IOV
IOG
IOV
IOG
A1
B1 C1
D1
A8
B8 C8
D8
IN1
IN2
IN3
IN4
NC
NC
NC
NC
SHT1+
SHT2+
SHT3+
SHT4+
IOV2
IOG2 SHT2- Input2-
IOV1
IOG1 SHT1- Input1-
IOV3
IOG3 SHT3- Input3-
IOV4
IOG4 SHT4- Input4-
Additional I/O
Power Supply
Unit*1
Use a two-conductor shielded
twisted-pair cable. Do not ground
the shield.
To use current input, connect
SHT
*
+ and SHT
*
- with a
short-circuit cable. *2
High-speed Analog Input Unit
NX-HAD402
Two-wire sensor
Three-wire sensor
Output device
Input+
Input-
*1. Besides the Additional I/O Power Supply Unit, some other Units can supply I/O power to the NX bus. For
example, you can use a Connected Communications Coupler Unit. If you use this Unit to supply I/O power
to the High-speed Analog Input Units, the Additional I/O Power Supply Unit is unnecessary. The Additional
I/O Power Supply Unit is also unnecessary if you do not use the trigger inputs of the High-speed Analog
Input Units.
*2. Short-circuit cables are not included in the product.
Precautions for Correct Use
The cable length of a short-circuit cable used for current input must be 4 cm or less and allow
for wiring to the screwless clamping terminal block. Be sure to use cables and ferrules that are
applicable to the screwless clamping terminal block. If the cable is too long, the analog input
values may not be accurate.
4-4-3
Precautions for Wiring
This section describes precautions that should be taken when you wire the High-speed Analog Input
Units.
• Precautions when the Unit is easily affected by noise
• Precautions when connecting a two-wire DC sensor
When the Unit is Easily Affected by Noise
If the Unit is easily affected by noise, use the following shielded wires and ground the end of the shield
on the High-speed Analog Input Unit side:
• Analog input
Two-conductor shielded twisted-pair cable
• Trigger input
For connection to a two-wire sensor: Two-conductor shielded twisted-pair cable
For connection to a three-wire sensor: Three-conductor shielded twisted-pair cable
4 Installation and Wiring
4 - 25
NX-series Analog I/O Units User’s Manual for High-speed Analog Input Units (W592)
4-4 W
iring External Devices
4
4-4-3
Precautions for Wiring