40120000 hex

PLC Function Processing Error

Omron · NX-series CPU Unit

What does 40120000 hex mean?

A fatal error has been detected within the PLC Function Module, indicating a critical software malfunction. This error leads to a partial fault level. The user program will stop, and the controller operation will cease.

Common Causes

  • An error occurred in the PLC Function Module software.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Cycle the Controller power supply (turn OFF and then ON) to attempt recovery.

Browse all codes in this manual (17)
Verified technical data. Last updated: March 2026

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