Precautions For Wiring - Omron Sysmac NX Series User Manual

 Wiring Example 2 (Analog input range: Current)
Additional I/O
Power Supply
A1
IOV
IOG
24 VDC
IOV
IOG
A8
*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
NX-series Analog I/O Units User's Manual for High-speed Analog Input Units (W592)
High-speed Analog Input Unit
Unit *1
B1 A1
IOV IN1
IOV1
IOG
IN2
IOV2
IOV IN3
IOV3
IN4
IOG
IOV4
B8 A8
NX-HAD402
B1 C1 D1
NC SHT1+ Input1+
IOG1 SHT1- Input1-
NC SHT2+ Input2+
IOG2 SHT2- Input2-
NC SHT3+ Input3+
IOG3 SHT3- Input3-
NC SHT4+ Input4+
IOG4 SHT4- Input4-
B8 C8 D8
4 Installation and Wiring
Use a two-conductor shielded
twisted-pair cable. Do not ground
the shield.
Output device
Input+
Input-
To use current input, connect
SHT + and SHT - with a
short-circuit cable. *2
Two-wire sensor
Three-wire sensor
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