Cause : STO product model identification error comes when the drive is having trouble identifying the STO module or its associated components correctly. 

"E01.06" in inovance MD800 drive indicate "STO product model identification error". This means the STO module might not be properly connected to the drive.

Troubleshooting Steps:

1. Check Connections: Ensure all cables and connections between the STO module and the drive are secure and correctly positioned.
2. Verify Compatibility: Check if the STO module is compatible with your specific MD800 drive model. Refer to the drive's manual for compatibility details.
3. Update Firmware: Make sure both the drive and the STO module are running the latest firmware versions. Update if necessary.
4. Inspect Wiring: Verify that all wiring is correct according to the installation manual. Look for any loose or damaged wires.
5. Replace STO Module: If possible, test with a known good STO module to see if the issue persists.
6. Check Parameters: Review the parameter settings in the drive related to the STO function and ensure they are configured correctly.