Hello, I am Bart Dring. I am the designer of this product and one of the original creators of FluidNC firmware. The profits from this controller directly help support the firmware development. Thank you for considering this product.
This is an optically isolated input CNC I/O Module designed for use with the 6 Pack Universal CNC Controller. It is used for switch inputs. It can use simple mechanical switches, opto interrupt switches, some proximity switches, and Hall effect sensors. The inputs would be used for limit/homing switches, probe, control switches and macro buttons.
It has a 3 position terminal block per switch input (Signal, +5V and Gnd). It is designed to be about as bullet proof to noise and voltage spikes as possible. It has opto isolated inputs with an isolated power supply. The signal is also filtered and sent through a Schmitt trigger. Dealing with noise and voltage spikes is a huge problem with CNC machines. This module makes those problems go away.
Documentation