Mach3 will not handle closed loop.
you will need additional hardware to close the loop.
you could do it with a good quality servo driver with dual loop capabilities but my understanding is that if you use steppers you are out of luck, i may be wrong because i dont use mach 3.

Quote Originally Posted by bodgeitandscarper View Post
hello all I am in the process of ripping an old fidia cnc 11 control of a 1989 ish vintage.I will replace it with Mach3, does anyone have any experience in using hiedenhain linear scale in a closed loop system with this setup.