Cause : Encoder connection error comes when he connection between the 11-wire encoder and driver is broken. The encoder rotates higher than the specified rate when control power is on.

"alarm 22" in panasonic servo drive indicate "Encoder connection error". This means a problem with the physical connection between the servo drive and the encoder. This error suggests that the drive is not detecting the encoder properly, which could be due to issues like faulty wiring, loose connections, or a damaged encoder.

Troubleshooting Steps:

1. Inspect the Encoder Connections:

• Check the Wiring: Ensure all wires between the encoder and the servo drive are securely connected and free from damage.
• Connector Inspection: Examine the connectors on both the encoder and the servo drive for bent or broken pins, corrosion, or any signs of wear.
• Tightness: Make sure that the connectors are fully seated and locked into place.

2. Check the Encoder:

• Physical Condition: Inspect the encoder for physical damage, such as cracks, dents, or other signs of mechanical stress.
• Alignment and Mounting: Ensure the encoder is properly aligned and securely mounted. Misalignment can cause signal issues that lead to connection errors.

3. Inspect the Cables:

• Cable Integrity: Check the integrity of the cables connecting the encoder to the servo drive. Look for any cuts, kinks, or abrasions that could interrupt the signal.
• Cable Routing: Ensure that the cables are routed properly, avoiding areas with high electrical noise or mechanical stress that could affect the signal.

4. Test with a Different Encoder:

• Swap Encoders: If possible, test the system with a different, known-good encoder to determine if the issue is with the encoder itself or with the servo drive.
• Test on Another Drive: Alternatively, connect the encoder to a different servo drive to see if the issue persists.

5. Check Servo Drive Settings:

• Parameter Review: Verify that the servo drive settings related to the encoder (such as the encoder type, resolution, and signal format) are correctly configured for the specific encoder being used.

6. Inspect the Servo Drive:

• Drive Diagnostics: Run any available diagnostics on the servo drive to check for internal faults or issues that might affect encoder communication.
• Connection Ports: Ensure that the encoder connection ports on the servo drive are not damaged.

7. Reset the Error and Monitor:

• Error Reset: After addressing potential causes, reset the error in the servo drive.
• Monitor Operation: Observe the system during operation to ensure the connection issue does not recur.