Cause : Absolute encoder counter overflow comes when the data of the multi-turn counter of the encoder exceeds the specified limit.

"alarm 41" in panasonic servo drive indicate "Absolute encoder counter overflow". This means the absolute encoder's counter has exceeded its allowable range. This error typically occurs when the encoder's position count surpasses the maximum value it can handle, leading to an overflow condition.

Troubleshooting Steps:

1. Check the Motion Range:

• Verify Encoder Limits: Ensure that the motion of the system is within the encoder's specified counting range. If the system is moving beyond the intended limits, the encoder may overflow.
• Mechanical Inspection: Check the mechanical setup to ensure that the movement is properly constrained within the encoder's operating range.

2. Review and Adjust Encoder Settings:

• Parameter Configuration: Review the servo drive’s parameters related to the absolute encoder, such as the encoder resolution and counting range. Make sure these settings match the specifications of the encoder.
• Set Software Limits: If your application allows, set software-defined limits to prevent the system from moving beyond the encoder’s counting range.

3. Inspect the Absolute Encoder:

• Encoder Condition: Physically inspect the absolute encoder for any signs of wear or damage that could affect its counting accuracy.
• Signal Integrity: If possible, use diagnostic tools to check the encoder signals for any anomalies that might indicate an overflow condition.

4. Monitor for External Influences:

• Electrical Noise: Ensure that the encoder wiring is not exposed to electrical noise or interference, which can cause erroneous counts or overflow conditions.
• Stable Power Supply: Verify that the encoder and servo drive are receiving a stable power supply, as voltage fluctuations can impact encoder performance.

5. Reset the Encoder:

• Reset Procedure: If the encoder has overflowed, reset the encoder’s position counter. This often involves reinitializing the encoder or resetting the drive’s position reference.
• Power Cycle: After resetting, perform a power cycle of the servo drive to clear the alarm and re-establish the encoder’s position reference.