Cause : Slave faulty in speed synchronous comes when speed synchronous is enabled, the master receives CAN communication data but does not detect the salve.

"Err55" in inovance MD200 drive indicate "Slave faulty in speed synchronous". This means a problem with the communication or synchronization between the drive and a slave device.

1. Check the slave CAN communication cable connection. 
2. Check whether CAN communication of the slave is normal.