EL
ErrorLib
Brands
||
  1. Home
  2. Fanuc
  3. Alpha i series AC Servo Motor
  4. 251
About·Privacy·Terms

ErrorLib — Industrial Fault Code Library

Disclaimer: ErrorLib is an independent technical reference tool. While we aim for accuracy, always verify with the manufacturer’s official service manuals before performing maintenance on industrial equipment. ErrorLib is not affiliated with the brands listed.

251

Invalid Input Data 2

Fanuc · Alpha i series AC Servo Motor

What does 251 mean?

Input data 2 specified with a function code is invalid. This indicates an issue with the format or value of the second input data.

Common Causes

  • Invalid input data 2 specified via a function code.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Check the input data 2 value specified with a function code.

Browse all codes in this manual (60)
Verified technical data. Last updated: April 2026

Related Faults

000Power-Down Required Parameter011Zero Feedrate Specified013Maximum Feedrate Zero
Source: Fanuc Alpha i series AC Servo Motor
Open Manual (Page 223)Search more codes in this manual