The problem.
The existing unit just measures the speed. If it is too slow then it pushes the UP button and waits for a while (beeping to say it is not at the right speed).
Too slow. Push the UP.
Too fast. Push the DOWN.
Stop. Keep pushing the DOWN. That is just plain DUMB.
Reverse. Push DOWN.
Stopped. Who knows. Push reverse.
Sh1T. Too fast, SLOW down.
Ahh, bugger. Start again.
It is ALL just DUMB.
The PWM and direction signal from Mach3 are perfect.
The front panel button operates a 'digital potentiometer chip' using the up and down button and the DC out of this PCB to control the motor is reasonable.
When I get time, I am going to make a new interface between the PWM and the motor controller. With a bit of coaxing the controller could be made to run a bit faster, but that's another story. With an ATC it needs to work better.
When the current limit is hit the spindle stops dead. OK.
But it DOES NOT hit the E-S or disable the feed, so we end up with a cutter smashing plow.
Watch this space in the NEW YEAR. I am too busy to fix my own at the moment.
Super X3. 3600rpm. Sheridan 6"x24" Lathe + more. Three ways to fix things: The right way, the other way, and maybe your way, which is possibly a faster wrong way.