22040

In Siemens HMI, navigate to Spindle > Parameters > MD 3300 (Spindle encoder assignment). Verify the encoder type supports MS detection (typically incremental encoder with MS pulse channel). Cross-reference with actual hardware configuration.

Do not change MD 3300 while spindle is rotating.

Perform spindle encoder referencing: Execute Diagnostic > Spindle > Initialize Encoder or use NC command G74 (spindle orient to zero marker) to force MS detection. Monitor encoder signals via Diagnostics > Signals > Spindle Encoder to confirm MS pulse appearance.

Ensure spindle is at standstill and safe position before executing G74.

Check SD 43340 (Spindle position actual value referenced to MS). After initialization, this value should equal zero. If it shows offset, the MS reference frame is corrupted; perform full spindle re-zeroing or replace encoder if signal is absent.

Verify MD 32400 (Spindle reference mode) is set to '1' (MS-based referencing required) if synchronized positioning is needed. If set to '0', MS referencing is optional and may allow the alarm to persist in certain positioning modes.

Check Diagnostics > Signals > Spindle Encoder for signal dropout. Look for encoder voltage (typically 5V or 24V supply) and pulse frequency stability. If signal is absent or unstable, inspect spindle encoder connector (usually circular M23 or M12), cable routing, and optical lens cleanliness.

Power down spindle drive and check for loose connectors before applying power.

Verify MD 3330 (Encoder pulses per spindle revolution) and MD 3340 (MS pulse position in encoder cycle) match the physical encoder specification. Mismatch causes NCK to misinterpret encoder data and lose MS synchronization. Cross-reference encoder documentation.

Monitor SD 43330 (Spindle encoder signal quality) in real-time diagnostics during spindle rotation. If quality drops below threshold during positioning attempt, the NCK invalidates the MS reference. Replace encoder or repair cable if degradation is confirmed.

After signal restoration, re-initialize spindle encoder via G74 or HMI spindle initialization function. Do not resume part program operation until SD 43340 returns to zero and shows stable values during test rotation.

After ESTOP recovery or manual spindle operation, check SD 43340 (Spindle position referenced to MS) and compare with actual spindle mechanical position. If values diverge significantly (e.g., SD shows 0° but spindle is physically at 45°), the reference frame is invalid.

Re-execute spindle encoder referencing: use G74 or HMI Spindle > Initialize command to re-synchronize NCK position model with physical MS marker. Ensure spindle completes one full revolution without interruption so encoder captures clean MS pulse.

Do not perform jog movements during G74 execution.