Could be.
I'd just hook up an optical or magnetic encoder IC with an affordable xilinx spartan-3 or 6 to the A axis directly and send that pulse over the vfd (if that'd be me).
Just never know what this bug'gy M3 could do... hence a hardware solution.
Have a look at the AM4096 12-bit magnetic encoder. Pretty lightweight and low cost implementation, if you need precision.
I see you are in embed from your url so that proposition might be a day work or two for you.
Otherwise no idea how you could pull this data out from M3 in a stable/real-time fashion way. Not too experienced with M3, just a user