Hi,
I'm not personally familiar with the PoKeys board.
I'm fairly sure that the 57CNC has lathe threading capability. What you need to find out is what the 57CNC expects.
It may be one of:
1) An index signal only, ie one pulse per rev.
2) A single A (or B) channel and an index signal
3) Full house, that is, A&B channels and an index signal.
An email to PoKeys or maybe a search of the PoKeys board on this forum will get you the answer.
Craig