Encoder error

This alarm occurs when two consecutive readings from the motor's encoder have a larger difference than expected.  The expected value range between encoder readings depend on the pulse-count-per-revolution and the current load of the controller.  Most likely, an encoder failure has occured, for example:

1. 1. One or two channels of the encoder are corrupted or disconnected
2. 2. There has been a mechanical failure of the encoder.
3. 3. Electrical noise induced onto the encoder (ie. from an electro-mechanical brake) can cause premature failure of the sensor bearing.

If the encoder and wiring are confirmed not to be faulty, then the logic of the controller must be replaced.