If you plan to use Mach4, you can use the PMDX-411 to control the PMDX-126.
The PMDX-411 is a USB device and is very simple to use.
You can also get a bundle discount worth $10 by purchasing the Mach4 software
along with the PMDX-411.
The PMDX-126 can also be used with the ESS and Mach4 if desired.