75016

Check the NC program block sequence around the alarm occurrence. Identify the TRAFOOF OFF command (disables clearance control) and the subsequent TRAFOOF ON command (re-enables it).

Review intermediate blocks for rotary axis movements (A, B, C axis commands or ROTS/ROT parameters) between the TRAFOOF OFF and TRAFOOF ON commands.

Verify the G17/G18/G19 plane active when TRAFOOF OFF was executed. This plane direction becomes the stored control direction in the transformation.

If rotary axes change orientation between TRAFOOF OFF and TRAFOOF ON, the tool direction relative to the workpiece will differ, triggering the alarm.

Insert an explicit orientation step change (ORIACOS or manual orientation command) immediately before the TRAFOOF ON command to synchronize the tool orientation with the new rotary axis configuration.

Use ORIACOS in the NC program or manually set rotary axis positions to match the expected tool orientation before re-enabling CLC.

Test the corrected program block sequence to confirm the alarm no longer triggers and the tool path follows the intended clearance control strategy.

Access the PLC/NCK diagnostics menu (typically via HMI or Siemens STARTER) and navigate to Machine Data > Kinematics > Rotary Axis Configuration (MD10200-MD10299 for each rotary axis).

Verify that rotary axis link parameters, zero offset values (MD10202, MD10207, etc.), and transformation reference frames remain consistent throughout program execution.

Check the 3D transformation and TRAFO parameters (MD20000+ series, especially TRAFO0/TRAFO1 kinematic chain definitions) to ensure the reference frame is correctly defined for both TRAFOOF OFF and TRAFOOF ON states.

If a TRAFO definition was modified or reloaded, the tool orientation calculation will change, causing the alarm.

Use the Siemens STARTER diagnostics function to compare stored machine data snapshots before and after the alarm event. Look for differences in rotary axis parameters or kinematic definitions.

If machine data was inadvertently modified, restore the correct kinematic configuration and reload the machine data via STARTER. Re-run the NC program to confirm the alarm is resolved.

Review the NC program between TRAFOOF OFF and TRAFOOF ON blocks for any G17, G18, or G19 commands that change the active plane definition.

Each plane change (G17 XY-plane, G18 XZ-plane, G19 YZ-plane) defines a different default tool direction; rotary axes must be positioned consistently with the new plane.