Hi,

I have a second parallel port installed on my PC which successfully runs the E-stop button, home and limit switches. I am trying to run a solid state relay off that port to power the spindle (on/off) using pin 17 and ground 19. I can run code with M3 and M5 commands which make the signal show as high and low on the diagnostics page but the measured voltage is a constant 3.2 for either condition.

I'm satisfied that I have the wiring and port and pin addresses correct yet I cannot make the pin follow what Mach is instructing it to. I do have an issue where the voltage is too low to trigger the relay but that is an entirely separate issue and will ultimately result in a replacement card, this is relating to what the pins on the breakout board are doing.

Any suggestions?

Cheers
Splint