AL025 alarm in delta ASDA-A2 servo drive indicates The internal of the encoder is in error. This means the internal of the encoder is in error. The internal memory and the internal counter are in error.

1. Check if the servo is properly grounded.
2. Check if the encoder cable separates from the power supply or the high-current circuit to avoid the interference.
3. Check if the shielding cables are used for the encoder.