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ErrorLib — Industrial Fault Code Library

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04C40000

Sensor Communications Error

Omron · NJ/NX-series Machine Automation Controller

What does 04C40000 mean?

An error occurred in an active sensor connection, signifying that a sensor has become disconnected or communication has been interrupted. This prevents the system from receiving data from the affected sensor.

Common Causes

  • Sensor cable disconnected
  • Sensor connection faulty

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify the nominal supply voltage at the affected sensor's power input terminals.

  2. 2

    Inspect all cabling connected to the affected sensor for physical damage, loose connections, or improper termination at both the sensor and the I/O module/controller.

  3. 3

    Check the status indicators (LEDs) on the relevant I/O module or network coupler for the affected sensor within the Omron NJ/NX system for any error or communication loss indications.

  4. 4

    Using Omron Sysmac Studio software, verify the I/O communication status, device diagnostics, and error logs for the specific sensor or I/O point reporting the error.

Browse all codes in this manual (96)
Verified technical data. Last updated: April 2026

Related Faults

04A10000Non-volatile Memory Hardware Error04A10000 hexNon-volatile Memory Hardware Error04AC0000 hexOvercurrent
Source: Omron NJ/NX-series Machine Automation Controller
Open Manual (Page 298)Search more codes in this manual