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ErrorLib — Industrial Fault Code Library

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F01B

Program Owner Active - Downloading or Online Editing

Allen-Bradley · Logix and SLC PLC

What does F01B mean?

This error occurs when a program is currently being downloaded or edited online by another user or process. This prevents other attempts to modify the program, ensuring program integrity during active development.

Common Causes

  • Another programming workstation is actively downloading code to the controller.
  • Another user is performing online edits on the running program.
  • Background task initiated a program modification.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify active programming sessions connected to the PLC using the appropriate programming software (e.g., Studio 5000 Logix Designer or RSLogix 500).

  2. 2

    Communicate with the identified user or responsible team to ascertain the status of their program download or online editing activities.

  3. 3

    Request that the active program owner finalize their changes or disconnect from the PLC to release program ownership.

  4. 4

    Monitor the PLC status indicators and programming software for the disappearance of the F01B error, indicating successful ownership release.

Browse all codes in this manual (39)
Verified technical data. Last updated: April 2026

Related Faults

1000Illegal Command or Format2000Communication Module Not Working3000Remote Node Missing or Disconnected
Source: Allen-Bradley Logix and SLC PLC
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