I have an ESS and 1024ppr differential encoder that has channels A, -A, B, -B, Z, -Z and I want to get it communicating with Mach.  I originally was just going to use the Z index channel and run it through the ESS but after some reading it seems that it may be possible to use the actual 1024ppr channels for better speed accuracy.  The main reason I want mach to know the RPM is so I can calibrate the spindle speed because the rpm/hz linearity is borderline acceptable but I would also like the capabilities of more accurate threading or rigid tapping (perhaps in the future).

Is this possible and how do I go about doing it?  Should I just stick with the Z channel?

As far as I know the ESS only supports the index. There was talk, maybe 3 years ago, of Greg implementing full encoder feedback for rigid tapping etc. As far as I know that has not been implemented and it is probably not going to happen.
Hood