10255

Press the RESET button to clear the alarm and cancel any pending operations in the affected channel.

Review the machine control panel alarm buffer and check if NC RESET or mode changes occurred immediately before alarm 10255.

Restart the NC program from a safe position or the beginning of the affected program block.

Ensure workpiece and tool positions are verified before restarting to prevent collisions.

If alarm recurs without operator intervention, proceed to check program structure and syntax issues.

Open the NC program in the editor and identify the block number where alarm 10255 occurred (check channel %1 alarm detail for block context).

Review program structure for excessive subroutine nesting (>8 levels), unconventional jumps, or multiple simultaneous ASUP activations in that section.

Simplify program structure by reducing nesting depth, consolidating subroutines, or splitting complex program sections into separate files.

Test the modified program section in single block mode to verify reorganization completes without interruption.

Monitor for alarm recurrence during lookahead processing of complex geometry.

Access the HMI and navigate to Commissioning > Version to verify the exact software version is 3.x or earlier as indicated by alarm description.

Check if the NC program was created or post-processed for a newer SINUMERIK version and contains syntax not supported in SW 3.x (review program header comments and G-code dialect).

Perform NCK system file consistency check via Service > NCK > File System and repair any detected errors.

Backup all NC programs and machine data before performing file system operations.

If system is SW 3.x, contact Siemens or consider software upgrade path to eliminate this legacy alarm condition, as it has been resolved in SW 4.x and later.

Software upgrades require qualified Siemens personnel and complete system backup.