EL
ErrorLib
Brands
||
  1. Home
  2. Allen-Bradley
  3. Logix and SLC PLC
  4. F01C
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.

F01C

Disk File Write Protected or Not Accessible (Offline Only)

Allen-Bradley · Logix and SLC PLC

What does F01C mean?

This fault applies specifically to offline operations and indicates that a disk file cannot be written to because it is either write-protected or otherwise inaccessible. This prevents saving changes or creating new files on the disk.

Common Causes

  • File system attribute set to read-only.
  • Insufficient user permissions to write to the specified disk location.
  • Disk corruption or network drive unavailability (for network files).

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Verify the logged-in user account has full read/write permissions for the directory containing the PLC project files.

  2. 2

    Check the properties of the PLC project file and its parent folder to ensure the 'Read-only' attribute is not selected.

  3. 3

    Inspect the available free disk space on the drive where the PLC project file is located to ensure sufficient capacity for saving.

  4. 4

    Verify no antivirus or security software is actively blocking write operations to the project file directory.

  5. 5

    Attempt to save the PLC project file to an alternate local disk location or a newly created folder to isolate the directory access issue.

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
Open Manual (Page 2)Search more codes in this manual