Configured for multi-channel analog signal acquisition and digitized temperature scaling in CJ Series backplanes, the Omron CJ1W-AD04U (CJ1W-AD04U Isolated-type Universal Input Unit) provides direct physical/electrical execution.

Architectural Designation and Input Configuration

The Omron CJ1W-AD04U functions as a Special I/O Unit mapped directly into the internal address table of Omron CJ-series CPU systems:

• CJ1W: Dedicated module platform housing for CJ1G, CJ1M, CJ2M, and CJ2H programmable controllers.
• AD: Analog-to-digital processing module architecture converting field input signals to 16-bit process registers.
• 04U: Designator specifying 4 channel inputs with universal signal processing (RTD, Thermocouple, Voltage, Current).
• Unit Number Allocation: Consumes exactly 1 Special I/O Unit address assigned via front rotary selector switches.

Physical and Electrical Specifications

Backplane Synchronization & Firmware Flash Execution

The module transfers digitized process variables across the local CJ backplane bus into dedicated CPU memory words every scan cycle. Internal backplane bus communication velocity handles fast register transfers without introducing firmware execution jitter. Dynamic scaling registers and onboard firmware flash compatibility maintain signal calibration parameters across power cycles without requiring external setup software reload routines.

Shipping Package Content

• 1 x Omron CJ1W-AD04U Isolated-type Universal Input Unit
• 1 x Removable front terminal block connector
• 1 x Hardware wiring and mounting instruction document

Field Installation & Wiring Guidelines

• Bus Power Cutoff: Switch off the main rack power supply prior to sliding the module into or out of the CJ-series CPU or expansion rack.
• Shielded Cabling: Route thermocouple, RTD, and 4-20 mA current signals using twisted-pair shielded cabling. Connect the shield drain wire to earth ground at the panel side only.
• Terminal Screws Verification: Tighten terminal block connection screws to a torque rating of 0.5 N m to ensure stable electrical continuity.
• Current Loop Resistors: Ensure correct wiring configurations when selecting current inputs to engage internal precision shunt loops without overloading inputs.

Frequently Asked Questions

• Can each of the 4 input channels be set to a different signal range on the CJ1W-AD04U?

  Yes. Range selections for Pt100, thermocouples, voltage, or current are configured independently per channel in system memory.

• What is the total conversion speed for updating all 4 analog channels?

  The unit completes a conversion cycle for all 4 inputs within a maximum sampling period of 250 ms.

• Does the CJ1W-AD04U require an external 24 VDC power supply to operate logic circuits?

  No. The module draws its operational power of 0.32 A directly from the internal 5 VDC PLC backplane bus rail.

• Is hot-swapping supported for the CJ1W-AD04U on a live CJ1 PLC rack?

  No. Removing or inserting the input unit while the PLC backplane power is active causes backplane bus errors and stops CPU execution.

• How many unit numbers does the module occupy in the PLC CPU memory map?

  The CJ1W-AD04U consumes exactly 1 Special I/O Unit address number set via the rotary switch on the module front panel.

• What happens if a thermocouple input wire breaks during system operation?

  The module detects a wire disconnection fault, sets a burnout flag bit in CPU memory, and drives the channel value off-scale.

• What type of external connection interface is provided on the front panel?

  Field wiring attaches via a removable screw terminal block, allowing module swap-outs without disconnecting individual signal wires.

• How does channel isolation benefit field measurements on process loops?

  Galvanic isolation between channels prevents ground loops and electrical interference from skewing signal conversion accuracies.