Reference Position Return is Abnormal

What does 90 mean?

This alarm indicates that the automatic reference position return (homing) operation for an axis could not be completed successfully or encountered an unexpected condition. This prevents the machine from establishing its absolute coordinate system.

• Mechanical obstruction or binding preventing the axis from reaching its home position.
• Faulty limit switch or reference position detection sensor.
• Incorrect setting of reference position parameters.
• Issue with the servo motor, feedback system, or amplifier affecting axis movement.
• Excessive noise on the encoder feedback line or reference position sensor signal.

Click steps to track your progress.

1. 1

   Inspect the mechanical axis for obstructions, damage, or excessive friction that might prevent homing.

2. 2

   Verify the functionality of the home position switch and overtravel limit switches for the affected axis using the diagnostic screen.

3. 3

   Check relevant parameters related to reference position return (e.g., Parameter 1320 for reference counter capacity) against machine specifications.

4. 4

   Monitor the servo motor's operation and encoder feedback during homing to identify any abnormal movements or signal loss.

5. 5

   Ensure proper grounding and shielding of sensor and encoder cables to prevent noise interference.