Looks like a straight forward match to the PMDX-107:
PMDX-107 SX3
AGND GND
AOUT AVI
AREF No connection
COM GND
Fwd/Run START/STOP
Rev/Dir F/R
And you need to set the DIP switches on the PMDX-107. I am presuming you have the PMDX-107 installed on a PMDX-126 and that your ARE using the charge pump signal on pin 17 (which we highly recommend). Let me know if you are not using a charge pump signal. See the PMDX-107's User's Manual section 4.1 to 4.5 for these DIP switch settings.
CONFIG1, CONFIG2: both "off" (normal mode)
CONFIG3: "On" (relay contacts act as "run" and "direction")
CONFIG4: "Off" (require "charge pump OK")
SLOW: either setting, start with "Off" for fast filter response.
5V/10V: "Off" (0 to 10V analog output - SEE NOTE BELOW!!!)
NOTE: you may need to adjust pot W1 on the SX3 board when the PMDX-107 is outputting 10V to set the max RPM on your spindle.
For the Mach3 configuration see our app note AN001 (
http://www.pmdx.com/AppNotes).