Okuma Alarm A-8649 – Measurement Sensor Unit Interlock

Alarm A-8649 indicates that movement of the measurement sensor unit is inhibited due to an interlock condition.

This alarm occurs when:

• A movement command is issued while the measurement sensor unit is in a locked or non-movable state, or

• An abnormal condition is detected during movement that makes continued motion unsafe.

The measurement sensor unit (such as a tool setter, probe arm, or in-process measurement device) is protected by interlock logic to prevent mechanical damage.

When this alarm appears:

• The sensor unit cannot extend or retract

• The control detects an invalid movement state

• The machine prevents further motion to avoid collision or hardware damage

Possible causes include:

• Mechanical obstruction

• Sensor unit not in home position

• Limit switch or position sensor fault

• Interlock signal active

• Air pressure insufficient (for pneumatic units)

• PLC logic condition not satisfied

Recommended actions:

1. Check that the measurement unit is free of obstruction.

2. Verify home position and limit switch signals.

3. Inspect pneumatic pressure (if applicable).

4. Check wiring and I/O signals related to the unit.

5. Reset the alarm and reinitialize the unit.

This alarm is a protective interlock and is intended to prevent mechanical damage to the measurement system.