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In Siemens HMI, navigate to Diagnostics > Alarms and note the timestamp and axis number. Cross-reference with alarm 27011 in the alarm buffer to confirm Safe Velocity was exceeded.

Check MD36800 $MA_SAFE_VELO_THRESHOLD value against actual axis velocity from Diagnostics > Axis > Actual Values. Verify threshold is appropriate for your machine's Safe Stop 1 deceleration capability.

If threshold is too low relative to normal operating speeds, increase cautiously and verify safe stop distance calculation per ISO 13849-1 requirements.

Verify $MA_SAFE_VELO_STOP_MODE (MD36810) and $MA_SAFE_VELO_STOP_REACTION (MD36815) are correctly configured. Confirm Stop 1 (value=1) is the intended reaction. Review in Diagnostics > Machine Data > Safety Parameters.

Check MD32410 $MA_DECEL_FACTOR_SAFE_STOP_1 to ensure the safety-rated deceleration value is realistic for the axis and load. If insufficient, the axis may not decelerate safely to trigger Stop D as intended.

Review alarm 27012 in the NCK alarm buffer to confirm Safe Position limit was exceeded. Cross-reference with Diagnostics > Axis > Actual Position to verify which limit (MIN or MAX) was violated.

Navigate to Diagnostics > Machine Data > Safety Parameters and verify MD36900 $MA_SAFE_POS_LIMIT_MIN and MD36901 $MA_SAFE_POS_LIMIT_MAX are set correctly for your machine's travel limits and workpiece constraints.

Ensure limits account for overshoot during maximum safe deceleration per MD32410.

Confirm $MA_SAFE_POS_STOP_MODE (MD36920) and $MA_SAFE_POS_STOP_REACTION (MD36925) are correctly configured with Stop 1 (D) as the intended reaction. Check if Safe Position monitoring is enabled via MD36902 $MA_SAFE_POS_ENABLE.

Verify axis encoder/position feedback integrity. In Diagnostics > Axis > Position Feedback, confirm actual position matches commanded position. A feedback fault or encoder fault (e.g., MD21050 $MA_ENC_FAULT_REACTION) could cause false Safe Position violations.

Check if latching mode is enabled: verify MD36810 $MA_SAFE_VELO_STOP_MODE or MD36920 $MA_SAFE_POS_STOP_MODE value is 2 (latching) in Diagnostics > Machine Data > Safety Parameters.

Attempt reset via HMI: Press Emergency Stop then Reset/Clear Alarm. If alarm persists, execute G-code command %RESET_SAFETY or use PLC interface to pulse the corresponding safety reset signal (typically via M3X function or SafeMC block reset).

Ensure machine is in safe state before attempting reset. Verify no ongoing Safe Velocity or Safe Position violation condition exists.