Heidenhain codes
HeidenhainServo/AxisIntermediate30-120 minutes

120-001F

HEIDENHAIN 120-001F - File not found

File not found

A file required by the control system is absent from the expected path. The filename or directory may be wrong, or the file may have been moved or deleted.

Root Cause Summary

This alarm is triggered when the control's file system cannot locate a referenced file at the specified path. The root cause is always a broken file reference - either the file was deleted/moved after the reference was created, the filename/path was mistyped, or a file transfer operation failed to complete. On Heidenhain TNC controls, file references are case-sensitive and must include correct path syntax (TNC:\, SYS:\, or network paths).

Safety

  • Refer to Heidenhain service manual
  • Ensure qualified technician performs repairs

Causes and Fixes

  1. 1

    Identify the calling line

    Press INTERNAL STOP if program is running. Note the block number displayed with the alarm. Open the active NC program and locate the CALL PGM or CYCL CALL statement that references the missing file.

    Use the Search function in the editor (GOTO key) to quickly find all CALL PGM statements in large programs.

  2. 2

    Verify filename and path syntax

    Check that the filename in the CALL statement matches exactly - Heidenhain is case-sensitive. Verify path format: use TNC:\ for internal memory, or full network path like \\SERVER\SHARE\FILE.H. Common error is using relative paths incorrectly.

    Heidenhain expects forward slash notation in newer controls or backslash with drive prefix. Avoid mixed separators.

  3. 3

    Search for the missing file

    Press PGM MGT key, then use the search function (soft key SEARCH or MOD function) to locate the filename across all drives. Check TNC:\, network drives, and USB if connected.

    The file may exist but in a different directory than expected. Note the actual location for path correction.

  4. 4

    Correct the reference or restore file

    Either edit the CALL statement to reference the correct path where file exists, or copy/transfer the missing file to the expected location. If file is completely missing, restore from backup or recreate it.

    Always verify program logic after changing CALL paths - ensure tool compensation and coordinate system context remain correct.

DIY Feasiblehigh confidence

Call a technician if:

  • ·System files corrupted beyond recovery
  • ·Hard drive or CF card hardware failure
  • ·Network infrastructure issues beyond TNC scope

Prevention

  • Maintain regular TNC system backups
  • Use UPS to prevent file corruption during power outages
  • Implement proper file naming conventions
  • Monitor storage media health regularly

Common Mistakes

  • Assuming files exist without verification
  • Ignoring case-sensitive file naming
  • Not checking file permissions after system updates
  • Copying system files between different machine configurations

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