Shows the physical configuration, wiring, and Mach4 integration of the proximity sensors on my CNC machine.
* http://www.pmdx.com/PMDX-424
* http://www.pmdx.com/PMDX-105 (Only needed if you use PNP proximity sensors)
* http://www.cncrouterparts.com/pepperl-fuchs-proximity-sensor-kit-p-293.html
* https://files.pepperl-fuchs.com/selector_files/navi/productInfo/edb/088241_eng.pdf
