OMRON CJ1W-AD04U Analog Input Module

OMRON CJ Series 4-Channel Isolated Universal Analog Eingabemodul (Special I/O Unit)

Status: Auslaufmodell. Available via spare parts and second-hand markets. Compatible with CJ1/CJ2/NJ-series PLCs. Independent signal type configuration for each of the 4 Kanäle, inter-channel isolation. Supports mixed acquisition of temperature sensors, 4~20mA and voltage signals, widely used in industrial process measurement.

✅ Model Explanation

CJ1W: Prefix for CJ-series Special I/O Units

ANZEIGE: Analoger Eingang

04: 4 Kanäle

U: Universal multi-type input

CJ1W-AD04U: Screw terminal type; CJ1W-AD04U-SL: Federklemme (Werkzeuglos) Version

📌 Core Specifications

✨ Features

1. Universal Mixed Input: 4 channels can be set to different types, z.B. CH1=Pt100, CH2=4~20mA, CH3=K-type thermocouple
2. Built-in Cold Junction Compensation for direct thermocouple use; 3-wire Pt100 measurement, max single wire resistance ≤20Ω
3. High/low limit alarm per channel, alarm delay 0~60s and hysteresis setting; open-circuit/error detection
4. Zero/Span calibration available during operation
5. Automatic value scaling; temperature values stored in CPU multiplied by 10 (z.B. 256.0℃ → stored as 2560)
6. Datenaustausch: Allocation Relay Area (measured values + alarm flags), DM Parameter Area (Reichweite, Alarm, channel type)

🛠 Installation & Verkabelungsrichtlinien

1. Mount on CJ CPU base or expansion base; it is a Special I/O Unit. Unit number and channel types must be configured in PLC software.
2. 3-wire Pt100: A/B/b three wires with equal length; B and b must NOT be shorted outside the module terminals.
3. Aktueller Eingang: Module integrates built-in 250Ω sampling resistor, connect in series directly into the loop.
4. Max input rating: Voltage ±15V; Current 30mA. Do NOT exceed range.
5. Warm up for 30 mins after power on to reach rated accuracy.

⚠️ Troubleshooting (Häufige Fehler)

1. ERR Red LED: Duplicate unit number, insufficient backplane 5V supply, lose Anschlüsse, incorrect parameter download
2. Fluctuating temperature reading: Cold junction interference for thermocouple, unbalanced resistance of 3 Pt100 wires, ground loop interference
3. Abnormal 4~20mA reading: Incomplete closed loop, missing external transmitter power supply
4. Open-circuit alarm: Broken sensor cable or poor contact

🔁 Alternative Selection Reference

Same-series upgraded model: CJ1W-PH41U (Faster sampling, wider signal types; also discontinued)

New project recommendation for NX series: NX-AD4204 / NX-TC3404 (Separate or universal temperature & analoger Eingang)

Simple alternative if only 4~20mA/voltage required: CJ1W-AD041 (Analog only, no thermocouple/RTD support)

📎 Supporting Document

Manual No.: W466-E1-02 (CJ1W-AD04U Operation Manual)

Compatible PLCs for CJ1W-AD04U (CJ-series Universal Analog Special I/O Unit)

This module is a CJ bus Special I/O Unit, mounted directly on CJ backplane. Restrictions apply for NJ/CP1H. Not compatible with CS series.

✅ Native Direct Compatibility (CJ1 CPUs, mount directly on CJ rack)

CJ1M: CJ1M-CPU11 / CPU12 / CPU13 (Including ETN Ethernet versions)

CJ1G: CJ1G-CPU42H / 43H /44H /45H; CJ1G-CPU42P/43P/44P/45P (Loop control type)

CJ1H: CJ1H-CPU65H / 66H /67H

✅ Native Direct Compatibility (CJ2 CPUs, mount directly on CJ rack)

CJ2M: CJ2M-CPU11 /12 /13 /14 /15 /31 /32 /33 /34

CJ2H: CJ2H-CPU64 /65 /66 /67 (Including -EIP Ethernet models)

✅ NJ Series (Maschinensteuerung, usable with caveats)

NJ501, NJ301 and other NJ controllers: Can use CJ1W-AD04U with CJ rack

Notiz: Still treated as Special I/O Unit under NJ system. Configuration software is Sysmac Studio, different from CX-Programmer for CJ. Some native CJ Special I/O instructions are unsupported.

✅ CP1H (Adapter required, cannot plug directly)

CP1H CPU has no native CJ backplane. Must use CP1W-EXT01 (CJ Unit Adapter). Maximal 2 CJ Special I/O Units (AD04U belongs to this category). CP1E/CP1L not supported.

❌ Incompatible

1. CS1 Series (CS1G/CS1H): Different backplane bus, cannot be used directly
2. CP1E, CP1L, CPM, CQM1, C200H: No support for CJ1W Special I/O modules at all
3. NX-series PLC: NX uses dedicated NX-AD modules, cannot mount onto NX backplane

📌 Important Usage Notes

1. Montageort: CPU rack or CJ expansion rack. Rotary switch on module front sets unit number (00~95). No duplicate Special I/O unit numbers.
2. Software: CX-Programmer for CJ1/CJ2; Sysmac Studio for NJ
3. Stromverbrauch: DC5V, 320mA. Calculate backplane power capacity during selection.
4. Max per system: Bis zu 40 CJ Special I/O Units (Limited by power supply and CPU capability)
5. Steps to Configure CJ1W-AD04U in CX-Programmer (CJ1M / CJ2M / CJ2H / CJ1G)

Voraussetzung: Set hardware rotary unit number (00~95). No duplicates among Special I/O Units. Record this number for software setup.

1. Neues Projekt & Select CPU Model
2. Open CX-Programmer → New Project
3. Device Type: CJ1M / CJ2M / CJ2H / CJ1G, select corresponding CPU
4. OK to enter project workspace
5. I/O Table and Unit Setup (Kernschritt)
6. Double-click [I/O Table and Unit Settings] in project tree to open rack view
7. Right-click empty rack slot → [Add Unit]
8. Kategorie: General Analog I/O → CJ1W-AD04U, OK
9. Select AD04U unit, right-click [Unit Settings] to open module parameter window

⚠️ Unit number must match hardware rotary switch! Beispiel: hardware set to 0, software unit number =0

3. Channel Parameter Configuration (Universeller Eingang, independent per channel)

Each channel can independently select sensor type: Pt100/Pt1000/JPt100 / K/J/T/L/R/S/B thermocouple /4~~20mA /0~~10V etc.

Channel Enable: Check to activate unused channels; disable unused channels otherwise alarms easily triggered

Eingabetyp: Dropdown to select sensor/range

Temperature Unit: ℃ / ℉ (for temperature inputs)

Alarm Settings: Upper/lower limit, alarm delay 0~60s, Hysterese; enable open-wire detection

Zero/Span Calibration: Optional online calibration

Averaging Processing: Reduce signal fluctuation (optional)

Register Allocation Rule:

Unit No. N:

CIO: Starts at `CIO 2000 + 100×N`

CH1 Measured Value: `2000+100N`

CH2 Measured Value: `2001`

CH3 Measured Value: `2002`

CH4 Measured Value: `2003`

Alarm flags and status bits in subsequent bits

DM Parameter Area: `D20000 + 100×N` stores channel type, range parameters

Beispiel: Unit No.=0

CH1 Value → CIO2000; CH2→CIO2001; CH3→CIO2002; CH4→CIO2003

4. Download and Online Verification
5. After parameter setup, [Transfer to PLC] (Download I/O table + special unit parameters together)
6. Switch PLC to Monitor mode and watch CIO channel readings
7. No ERR red light = basic configuration OK. ERR red light causes: mismatched unit number, insufficient backplane 5V, falsche Parameter

Wichtiger Hinweis: AD04U is a Special I/O Unit. Parameters download into PLC memory and auto-load to module on power-up. No initialization instructions required in user program.

1. Restrictions for CP1H + CP1W-EXT01 + CJ1W-AD04U

Hardware architecture: CP1H CPU + CP1W-EXT01 Adapter + CJ Backplane + CJ1W-AD04U

✅ Erlaubt

1. Maximal 2 CJ Special I/O Units (AD04U counts as Special I/O; combination: 1×AD04U + another CJ Special I/O)
2. Only supports CJ Special I/O Units / CPU Bus Units; CJ basic I/O (CJ1W-ID/OD) cannot be mounted
3. CX-Programmer configuration is nearly identical to CJ setup: Add AD04U in I/O table and set unit number

❌ Hard Limitations

1. Max Quantity: 2 Einheiten, cannot add 3rd. Two AD04Us allowed but 5V backplane current budget must be validated (320mA per AD04U)
2. Extension length: Only one segment of CJ base after EXT01; No further CJ expansion base or expansion cable cascading
3. Partial advanced CJ Special I/O instructions unavailable; basic acquisition and alarm functions of AD04U work normally
4. CP1H program capacity and CIO address space limited; avoid large unit numbers, empfohlen 0, 1
5. Stromversorgung: 5V power for CJ rack after EXT01 must have sufficient capacity. Two AD04Us draw total 640mA, reserve ≥30% margin accounting for base consumption
6. CP1E / CP1L cannot use EXT01, only CP1H (XA/X models)
7. Adresse: CIO and DM offset rules same as CJ, but CP1H CIO area limited, unit number ≤15 recommended

⚠️ Common Pitfalls

1. Missing CJ1W-TER01 terminator at the end of EXT01 rack (supplied with adapter, I/O error if missing)
2. Duplicate unit number on two modules → ERR red LED
3. Wrong selection: Attempt to mount CJ1W-ID211 DI/DO basic unit after EXT01 → Not recognized
4. Insufficient backplane 5V current: ERR flashes after power on, no measurement data

Simplified Debug Procedure for CP1H + AD04U

1. Hardware wiring: Mount CP1W-EXT01 on CP1H side port → CJ base → AD04U, install CJ1W-TER01 terminator at rack end
2. Set AD04U rotary unit number to 0 (oder 1)
3. New CP1H project in CX-Programmer, open I/O table, add CJ1W-AD04U under EXT01 expansion rack, match unit number to hardware
4. Set 4-channel input types and download I/O table + Parameter
5. Online monitor CIO area to read temperature/analog signals

Engineering Application Cases of OMRON CJ1W-AD04U (Universal Analog Input Module)

Core advantages: Independent 4-channel setup, inter-channel isolation, mixed acquisition of Pt100/thermocouple/4~~20mA/0~~10V. Ideal for small reactors, Sterilisatoren, heat exchange stations, Wasseraufbereitung, ovens and other mixed-sensor process applications.

PLC Host: CJ2M / CJ1M / CJ1G; HMI options: NB/NS Touchscreen, CX-Supervisor SCADA

Fall1: Temperatur & Pressure Monitoring for Small Reactor (Typical AD04U Application in Chemical/Pharmaceutical)

Projektanforderungen

Reactor multi-signal acquisition:

CH1: Pt100 (Vessel temperature 0~~200℃, 3-wire RTD)

CH2: K-type thermocouple (Jacket temperature 0~~400℃)

CH3: Pressure transmitter 4~~20mA (0~~1.0MPa)

CH4: Level transmitter 4~~20mA (0~~2m liquid level)

Funktionen: Limit alarm, open-wire detection, real-time HMI display, over-temperature interlock output via DO module.

Hardware Architecture

CJ2M-CPU13 + CJ1W-AD04U (Einheit 0) + CJ1W-OD211 Digital Output + NB Touchscreen

AD04U handles mixed signals across four channels, eliminating separate temperature module and regular AI module to save rack slots.

Wichtige Konfigurationspunkte

1. Add CJ1W-AD04U in CX-Programmer I/O Table; hardware rotary switch 00
2. Channel setup

CH1: Pt100, open-wire detection enabled; linearization onboard, stored value ×10 (256.0℃→2560)

CH2: K thermocouple, built-in cold junction compensation

CH3: 4~~20mA, range 0~~1MPa

CH4: 4~~20mA, range 0~~2m

3. Adresse (Einheit 0)

CH1 Temperature: CIO2000; CH2: CIO2001; CH3 Pressure: CIO2002; CH4 Level: CIO2003

4. Programm: SCL scaling, high/low limit comparison; channel open-wire bit triggers alarm, over-temperature triggers DO to cut heating.

Field Debugging Issues

Thermocouple shield cable single-end grounding. Ground loop and temperature fluctuation occur with both ends grounded;

Unequal resistance of three Pt100 wires leads to reading drift, keep three wires same length;

30-minute module warm-up before reaching rated accuracy.

Fall2: Food Sterilizer (Steam Sterilization Equipment)

Anforderungen

Multi-point temperature measurement inside chamber, monitor cavity temperature and steam pressure for pasteurization / high-temperature sterilization process logging.

CH1: Pt100 Chamber Temperature 0~~135℃

CH2: Pt100 Product Core Temperature

CH3: 4~~20mA Steam Pressure 0~0.4MPa

CH4: Reserved for cooling water K thermocouple

System Features

Sterilization site has heavy electrical interference, inter-channel isolation of AD04U delivers better noise immunity than non-isolated regular AI. Data uploaded to touchscreen to save process curves for food batch traceability.

Erweiterung: Add CJ1W-DA021 analog output module for PID temperature control to modulate steam regulating valve.

Fall3: Heat Exchange Station (HVAC / District Heating Substation)

Anforderungen

Primary supply temp, primary return temp, supply pressure, return pressure

CH1: Pt100 Primary Supply

CH2: Pt100 Primary Return

CH3: 4~~20mA Supply Pressure 0~~1.6MPa

CH4: 4~~20mA Return Pressure 0~~1.6MPa

SPS: CJ1M-CPU12; Remote SCADA, heat calculation, high/low pressure and overtemperature alarm.

Wichtige Punkte

Sensors distributed over long wiring distances in heating stations. Built-in open-circuit detection alerts maintenance staff immediately on probe failure.

Fall4: CP1H+CP1W-EXT01+CJ1W-AD04U Low-cost Water Tank Temperature & Level Monitoring

Hardware

CP1H-X40DT-D + CP1W-EXT01 Adapter + CJ Base + CJ1W-AD04U + CJ1W-TER01 Terminator

Einschränkung: Max 2 CJ Special I/O Units; nur 1 AD04U used here

Kanäle:

CH1: 4~~20mA Liquid Level 0~~5m

CH2: Pt100 Water Temperature

CH3, CH4 Reserved

Anwendung: Water purification / sewage tank, pump start-stop interlock by liquid level, overtemperature alarm.

Notiz: No CJ basic DI/DO allowed after EXT01, only Special I/O; calculate 5V backplane consumption (320mA for AD04U).

Fall5: Oven / Heat Treatment Furnace Monitoring (K Thermocouple Dominant)

CH1/CH2 K thermocouple for multi-point furnace temperature; CH3 4~~20mA fan wind pressure; CH4 0~~10V speed potentiometer.

Suitable for small heat treatment and drying ovens. Supports thermocouple + Stromspannung + current within single module, which is the biggest advantage of AD04U. Regular CJ1W-AD041 only handles 4~20mA/voltage and does not support RTD/thermocouple.

General Programming Guidelines for CJ1W-AD04U

1. Temperatur (Pt100/Thermocouple): Onboard linearization, raw value = actual temperature ×10;

Beispiel: CIO2000=1250 → 125.0℃

2. 4~20mA Raw Range: 4mA corresponds to 1/12000, 20mA corresponds to full scale; SCL instruction scales engineering value in PLC program
3. Alarms: Module hardware provides per-channel high/low limit and open-wire bits in subsequent CIO bits, no need to write comparison logic for open-circuit detection.

Auswahlhilfe (When to choose AD04U)

✅ Suitable: Mixed sensor types (Pt100, thermocouple plus 4~~20mA transmitters), inter-channel isolation required, ≤4 points

❌ Nicht geeignet: Pure 4~~20mA acquisition with many points (CJ1W-AD081 recommended); high-speed sampling (CJ1W-PH41U recommended)

Summary of Common Faults in Field Commissioning

1. ERR Red LED: Duplicate unit number, insufficient backplane 5V power, I/O table parameter not downloaded
2. Jumpy temperature reading: Shield cable grounded at both ends, sensor cables routed together with power cables
3. 4~20mA locked at 4mA: Transmitter loop open, 2-wire transmitter wiring error
4. Pt100 reading drift: Unequal resistance among three wires