Hi. I am building my own gantry type cnc router using a Windows Xp desktop running Mach3. The bob is the DB25-1205F and my problem is in connecting the E-stop and limit switches. I have P10 set up for the e-stop, P11 for the touch probe and P12, P13 and P15 for the limit stops. All are enabled with port 1 and the correct pins allocated and set to active low. With nothing connected to the inputs I find there is +4v between each input and the ground adjacent to P15. If I short each input to ground in turn I get the correct led lit up on the dignostics screen. I also get the same result if I short the e-stop input through its NC switch but when I connect the switch permanently Mach3 doesn't react in any way to the e-stop button being pressed. The touch probe doesn't work in this way either. I haven't yet tried this with the limit switches. I am starting to think I need to connect a resistor to each input but I don't know what value and how I should connect it. Can anyone help me please.

Panic over! I've found the problem. I soldered a wire to the wrong terminal on a bulkhead connector. All is now working as it should.