Omron NX-AD3603 — 4-Ch ±10 V Analog Input, NX Series

Product Overview

The NX-AD3603 is a 4-channel voltage analog input unit for the NX-series I/O system. It plugs onto the right side of an NX102, NX1P2, or NJ501 CPU, or onto an NX-EIC202 / NX-ECC202 EtherCAT coupler, and exposes four -10 to +10 V single-ended inputs with 1/8000 (13-bit) resolution. It is the right pick when you need to read bipolar analog signals — a servo drive velocity command, a hydraulic valve positioner, a load-cell amplifier with a ±5 V output, or any sensor that swings both above and below zero — into the NX rack without adding external signal conditioning.

Where NX-AD3603 sits in the voltage-input lineup

The NX analog input family splits along three axes: number of channels (2 / 4 / 8), signal type (voltage -10 to +10 V or current 4 to 20 mA), and input circuit (single-ended or differential). Within the 4-channel voltage tier you have two choices: NX-AD3603 (this SKU, single-ended, 1/8000 resolution, 250 µs/point, Free-Run refresh) and NX-AD3604 (differential, 1/30000 resolution, 10 µs/point, selectable Synchronous or Free-Run). Single-ended is cheaper and adequate when signal sources share a common ground — typical for sensors near the panel, valve positioners, and DC drives.

Conversion time, accuracy, and what they mean in practice

At 250 µs per point, the NX-AD3603 scans all four channels in about 1 ms, well within the 1–2 ms typical task period of an NX EtherCAT slave. Free-Run refreshing means the module samples independently of the EtherCAT cycle — the most recent sample is what the controller reads, with the freshness stamp in the data header. If you need deterministic sampling aligned to the EtherCAT cycle (for example to drive a synchronized motion control loop), move to the NX-AD3604 which supports Synchronous I/O refresh.

Wiring and common pitfalls

The NX-AD3603 uses the same removable screwless push-in terminal block as the rest of the NX family — 16 terminals, push-in for solid or ferruled wires 0.14 to 1.5 mm² (26–16 AWG), strip length 8 to 10 mm. Terminals A1–A4 are the four +V inputs, terminals B1–B4 are the four commons (linked together internally on a single-ended module, so all four sources must share a common 0 V). Absolute maximum input voltage is ±15 V — exceed this and you will damage the front end.

Key Features

• 4 analog input channels, -10 to +10 V single-ended voltage
• 1/8000 resolution, ±0.2 % full-scale accuracy at 25 °C
• 250 µs/point conversion time, full 4-channel scan in ~1 ms
• Free-Run I/O refresh, aligns naturally with 1–2 ms NX task periods
• 12 mm wide NX housing, slides onto NX bus for EtherCAT or local I/O
• Screwless push-in terminal block accepts 0.14–1.5 mm² wire with ferrules
• Input impedance 1 MΩ min, absolute maximum ±15 V
• Setup via Sysmac Studio: scaling, moving average, disconnection detection

• SKU: NX-AD3603
• Series: NX (Analog I/O)
• I/O: 10 I/O

Resources & Downloads

• Product Datasheet.pdf
• CAD Files.zip