Hello Chris

If you are using the on board 0 - 10 volt analog motor control on the C11 board for Spindle speed then then I would think all you would need to do is find the negative or ground wire and the positive wire on the hall sensor and run it to a negative input and the positive to one of your inputs on your C11 board and set that pin as the index in ports/pins inputs. As the magnet on the spindle goes by the hall sensor it produces an electrical voltage pulse which Mach 3 will use as you RPM tachometer and also to do the spindle speed averaging.  To be sure if you could do it that way you could email Arturo at CNC4 PC to be sure. I think that might work but I would be absolutely sure before you wired anything up. I think you hall sensor can't put out more than a 5 vdc signal for the C11 board.

Eric

 tried some voltage testing and the pulse signal was very low, under 1v... And fluctuating faster then my multimeter could keep up so I don't know if it is higher and my meter just caught a glimpse or if that's even a possibility... Lol

I did try connecting it but it had very high and radically changing readings like over 1,000,000 rpm..

Now it just shows 1rpm when I hook it up and zero rpm when it's disconnected so I'm not sure what's going on.

Chris