Changing from Mach 3 to Linux

woffler wrote:

I found a board called mesa 7I52 6 encoder would this work as a daughter board to input the differential encoder from the spindle on port 2?

Not easily, that is one of the 50-pin header style boards for the 5i20, 5i22, 5i23.

You need one of these: store.mesanet.com/index.php?route=product/category&path=83_87

If you have differential encoders, and want to wire differential. If you can wire single-ended and the voltage is TTL then I think you can connect direct to the 5i25.