20210

Check the NC block triggering alarm 20210 in the part program. Verify that an explicit S word (spindle speed) is programmed before or within the centerless grinding cycle block. Confirm the S value is non-zero and appropriate for the wheel material and workpiece diameter.

Verify spindle enable state via Diagnostics > Spindle menu. Ensure MD 20070 (spindle speed assignment) is correctly configured and the spindle is in 'ready' state. Check that no M03/M04/M05 commands are suppressing spindle activation.

If using spindle master/slave mode, confirm the master spindle speed is propagating to the grinding spindle via SD 43110 (spindle 2 speed actual value). If not, check encoder feedback and spindle coupling parameters.

Verify spindle coupling is enabled before testing; incorrect coupling can cause loss of synchronization.

Check the X and Y axis positions in the NC block. Verify they fall within machine soft limits (MD 36000 Lower Limit, MD 36010 Upper Limit for each axis). Use Diagnostics > Axis > Position to display current vs. programmed positions.

Review the centerless grinding cycle parameters (typically CYCLE832 or machine-specific macro). Confirm that wheel radius offset, workpiece diameter reference, and approach distance values are realistic and non-conflicting. Check for zero or negative diameter values in the cycle call.

Perform a manual axis jog to the intended grinding position. Observe whether the axes reach the target or stop at a limit. If limit is triggered, reduce the programmed offset or adjust MD 36000/36010 limits in consultation with machine documentation.

Always enable feedhold and reduce feedrate to minimum before manual jog testing on centerless grinders.

Review the CYCLE832 (or custom grinding cycle) call syntax in the NC block. Verify all mandatory parameters (workpiece diameter D_WP, wheel diameter D_WHEEL, feed rate F) are present and non-zero. Cross-reference the cycle definition in the machine's macro library under Diagnostics > Program > Macro.

Check that D_WHEEL is less than D_WP and both values match the actual installed tool geometry. Confirm units (mm vs. inches) are consistent with MD 1025 (metric/inch mode). Edit the NC block to correct any parameter mismatches.

Clear alarm 20210 via RESET and re-run the corrected NC block at reduced feedrate (MD 32840 reduced feedrate %) to verify the diameter calculation succeeds and S value updates in the Spindle diagnostics display.