The fault code 6481 in your ABB ACS880 drive indicates a task overload within the control unit. This means the drive's control unit is overloaded and unable to keep up with the processing demands required for proper operation.

Understanding Task Overload:

1. The control unit of the ABB ACS880 drive is responsible for various tasks, including receiving control signals, interpreting them, managing communication with the power unit, and ensuring motor operation according to set parameters.
2. A task overload signifies that the control unit is struggling to handle the workload due to various reasons.