Cause : Full close selection error comes when an 11-wire encoder is used, Pr02 (con- trol mode selection) is set to 7, 8 or 9 ("full- close" control).

"alarm 97" in panasonic servo drive indicate "Full close selection error." This means there is a problem with the full-closed loop control setup. This alarm typically arises when the drive detects an inconsistency or configuration issue in the settings required for full-closed loop operation, where feedback is taken from an external encoder rather than the motor's built-in encoder.

Troubleshooting Steps:

1. Verify Full-Closed Loop Configuration:

• Check Settings: Ensure that the drive is properly configured for full-closed loop operation. This involves setting the correct parameters for external encoder feedback and ensuring that all necessary options are enabled.
• Parameter Review: Double-check that the parameters related to full-closed loop control, such as external encoder settings, feedback source, and control mode, are correctly configured according to your system’s requirements.

2. Inspect External Encoder:

• Connection Check: Verify that the external encoder used for full-closed loop control is properly connected to the servo drive. Check for secure connections, correct wiring, and any potential issues like loose connectors or damaged cables.
• Encoder Compatibility: Ensure that the external encoder is compatible with the servo drive and that its specifications match the drive’s requirements.

3. Check for Signal Integrity:

• Signal Verification: Use diagnostic tools to verify the integrity of the signal from the external encoder. Ensure that the encoder is providing accurate and consistent feedback to the drive.
• Noise and Interference: Ensure that the encoder signals are not affected by electrical noise or interference, which could lead to incorrect feedback and trigger the alarm.

4. Review System Parameters:

• Control Mode Settings: Ensure that the control mode is set correctly for full-closed loop operation. Some drives may require specific modes or options to be enabled when using an external encoder for feedback.
• Re-initialize System: After verifying and adjusting settings, it may be necessary to reinitialize the drive or control system to apply the changes correctly.

5. Firmware Updates:

• Update Firmware: Check for firmware updates for your Panasonic servo drive that address issues related to full-closed loop control. Manufacturers may release updates to fix bugs or improve functionality in specific control modes.
• Reinstall Firmware: If the firmware is current, consider reinstalling it to eliminate the possibility of software corruption affecting the drive’s performance.

6. Power Cycle the System:

• Restart System: Perform a power cycle by turning off the servo drive and then turning it back on. This can help reset the system and clear any temporary errors.
• Monitor Performance: After the system restarts, monitor the drive’s behavior to see if the alarm reoccurs, indicating a persistent issue.