Er.B04 fault in inovance IS650 servo drive indicates Fully closed-loop function parameter setting error. This means in full closed-loop mode, position reference source is internal position reference but internal encoder feedback and external encoder feedback is switched over.

1. Check whether position reference source is internal position reference: multi-position and position change on fly.
2. In full closed-loop mode, when position reference source is internal position reference, only external encoder feedback can be used. That is, H0F-00 can be set to 1 only.