I am using AD2S1205 LOT/DOS diagnostic feature to identify fault, by testing RDC EVAL board, looks it is quite accuracy to identify whether or not SIN/COS cable connection is removed or not, even in the situation when resolver is in startionary.
From AD2S1205 datasheet, there is Monitor Signal inside which is used to monitor SIN/COS signal and detect the fault issue, the description is as attached. With this description, my understanding is that it is necessary for resolve to rotate at least one cycle to correctly detect fault, e.g. cable disconnection, SIN/COS amplitude mismatch, over/under threshold etc etc. If in case resolver is in stationary & SIN/COS signal amplitude is in lowest value, it is impossible for RDC to identify disconnection fault if using Monitor Signal, it should take resolver to rotate at least one cycle before identify it, but the fact is not as this case.
That is where my question is going, and I suppose there is a another scheme for RDC to detect fault when resolve is in stationary status.
Another question is that according to datasheet Loss Of Tracking fault means internal error is more than 5 degree, but it is difficult to understand, the question is how RDC to know the exact error more than 5 degree? and is there fumula avaialable to calculate it?
It is very helpful if somebody available to answer my question and share information.
Thank you & best regards