1A1-0052

Inspect PLANE SPATIAL definition

Open the NC program and locate the PLANE SPATIAL command. Check that the spatial position vector (SPA, SPB, SPC) or direction vector components are non-zero and properly formatted. Example: PLANE SPATIAL SPA+0 SPB+0 SPC+0 would be invalid.

Use PLANE RESET before defining a new PLANE SPATIAL to clear any residual orientation data that might conflict with new calculations.

Verify vector length parameter

If using vector notation (X, Y, Z, L format), ensure the L parameter is explicitly defined and greater than zero. In Test Run mode (MOD > Program Run > Operating Mode), check the active plane display to confirm vector calculation.

The TNC normalizes vectors internally, but L=0 or undefined causes immediate calculation failure before normalization occurs.

Test with known-good vector

In MDI, enter: PLANE SPATIAL SPA+0 SPB+0 SPC+1 DIST+100 and execute. If this works, the issue is in your program's vector definition. If it fails, check kinematic configuration.

Ensure rotary axes are in safe position before testing PLANE commands to avoid unexpected axis movements.

Review spatial angle values in program

Locate NUT and NUTP definitions in your NC program (typically in PLANE SPATIAL or Cycle 19/CYCL DEF 19 WORKING PLANE). Check if NUT is at or very near ±90 degrees, which creates a singularity.

NUT values between 89.9 and 90.1 degrees often cause this alarm. Consider restructuring the operation or using vector notation instead of spatial angles.

Check active transformation settings

Press MOD key > Settings > Kinematics Opt. Verify the 'Singularity handling' parameter. If set inappropriately for your kinematic type, the control may reject valid angles.

Changing singularity handling affects all 5-axis operations - document original settings before modification.

Test alternative orientation method

Replace the spatial angle definition with an equivalent PLANE VECTOR or PLANE EULER definition to bypass the NUT/NUTP calculation. Use the TNC's plane calculator (MOD > Plane Functions > Calculate) to convert between formats.

PLANE EULER with Euler angles often handles near-singular positions better than spatial angles in certain kinematic configurations.

Verify active kinematics table

Navigate to MOD > Machine > Kinematics > Active Kinematics. Confirm the correct kinematics number is active. Then select 'Display kinematics' and verify all axis definitions (translational and rotational) are complete with valid data.

Do not modify kinematics tables without proper backup and machine manufacturer documentation - incorrect kinematics can cause crashes.

Check rotary axis limit parameters

In the kinematics display, review the software limit switches for rotary axes. Cross-reference the programmed tool orientation against these limits using the Plane Calculator (press PLANE key, then 'Calculate' soft key) to see required axis positions.

Some machines have asymmetric rotary limits - a tool orientation may be reachable in one quadrant but not another with identical inclination angle.

Verify transformation type compatibility

Check if FUNCTION TCPM is active (appears in Program Run mode status). Ensure the TCPM type (F TCPM AXIS...) matches your kinematic structure. Incorrect TCPM axis assignment prevents proper inclination calculation.

Use F TCPM RESET in MDI to clear all TCPM functions, then re-enable only what's needed. Residual TCPM settings from previous programs often cause unexpected calculation errors.