6 Axis CNC MACH3 Engraving Machine Interface Breakout Board USB PWM Spindle with ASKPOWER A131 Series
Powering the board
This board needs two power sources as they claim that isolating the digital from analogue part of the board is great idea.
In short: power the board by 24V and USB connection and it will all work.
In reality it might depends on what you need. if you need only to power outputs (for motor drivers) it will happily work from USB connector. All you need to do is set you limit switch Active low in Mach3 as you do not have any signal input.
If you need Inputs (no PWM no Relays) and you have only 5V you can connect them to "5V out" connection. Obviously this is not the intended use but it works fine.
The intended use is the "12V-24V Power input connection" (on image marked as 24V). Manual says 12-24 which is not the whole explanations.
If you power the board by 12V you get 5V output, power for your inputs and PWM signal. "PWM 0-10V" terminal will be outputting 0-10V.
If you power the board by 24V you get all prevoius + the 3 Relays will work as they need 24V.
When the board is powered by USB the "5V Output power by USB" connections will have 5V. But trough these same connections the board can be powered by 5V instead the USB.
So at the end the 5V analogue output could power the 5V digital input to eliminate the USB supply for the board but you will lose the separation and that is probably not a good idea and again, not intended use of the board.
Acknowledgments, Credits, and Bibliography