OMRON CJ1W-IA111 16-Point AC Digital Input Unit

Technical Overview

The OMRON CJ1W-IA111 is a professional-grade 16-point AC digital input module designed for the CJ1, CJ2, and NJ series Programmable Logic Controllers (PLCs). Featuring a rated input voltage of 100 to 120 VAC (50/60 Hz) and a 7 mA typical input current, it seamlessly integrates AC-powered external devices, limit switches, and sensors into industrial control architectures. The unit utilizes a robust removable M3 screw terminal block for reliable field wiring and features an adjustable digital filter (0 to 32 ms) to mitigate the effects of external electrical noise. With a compact footprint and isolated circuitry, the CJ1W-IA111 guarantees dependable operation and high noise immunity in demanding industrial automation environments.

Key Features

16 discrete AC input points (1 word allocated).
Adjustable digital noise filter (0 to 32 ms) for reliable signal processing and debouncing.
Removable M3 screw terminal block for streamlined installation and maintenance.
Compatible with OMRON CJ1, CJ2, and NJ series PLC platforms.
2,000 VAC dielectric strength between external terminals and GR terminal for robust isolation.
Fast default response times of 18 ms (ON) and 48 ms (OFF) adaptable via settings.

Technical Specification Matrix

Parameter	Value
I/O Points	16 AC digital inputs
Rated Input Voltage	100 to 120 VAC (50/60 Hz)
Operating Voltage Range	85 to 132 VAC
Input Current	7 mA typical (at 100 VAC, 50 Hz)
Input Impedance	14.5 kΩ (50 Hz), 12 kΩ (60 Hz)
ON Response Time	18.0 ms max. (default: 8 ms)
OFF Response Time	48.0 ms max. (default: 8 ms)
Internal Current Consumption	0.09 A (at 5 VDC)
Dielectric Strength	2,000 VAC (1 minute)
Dimensions	90 mm x 31 mm x 89 mm
Connection Type	Removable screw terminal block

Industrial Applications

1. AC Motor Contactor Feedback Monitoring

Integrates with 120 VAC motor control centers to monitor the auxiliary contacts of AC contactors and motor starters. The 16 input points allow a single module to track the operational status of multiple pumps or fans simultaneously.

Problem Solved

Directly reads 120 VAC signals without requiring interposing relays, simplifying panel wiring and reducing points of failure in HVAC or heavy motor control systems.

120 VAC inputContactor feedbackMotor control centerStatus monitoringNo interposing relays

2. Heavy Machinery Limit Switch Integration

Connects to ruggedized 120 VAC mechanical limit switches used in heavy manufacturing, such as stamping presses or material handling conveyors, passing direct machine state data to the CJ-series PLC.

Problem Solved

Utilizes the module's adjustable digital filter (up to 32 ms) to debounce mechanical switch contacts in high-vibration environments, preventing false triggering and logic errors.

Mechanical limit switch120 VACAdjustable digital filterSignal debouncingHigh-vibration environment

3. Facility Power & Lighting Automation

Used in building automation to detect the ON/OFF state of manual lighting override switches or local power circuits that operate on standard 120 VAC mains voltage.

Problem Solved

Bridges the gap between 120 VAC commercial infrastructure and 5 VDC PLC logic processing, leveraging 2,000 VAC dielectric strength to safely isolate the sensitive CPU from mains power spikes.

Building automationMains voltageGalvanic isolation2,000 VAC dielectric strengthLighting circuits