Proximity switches or limit switches

[Neale]

I can't comment on the switch wire colours without a diagram in front of me, but you do need to take a wire from the -ve pin for your chosen input to the common negative - on the IP/M both sides of the inputs are floating. In Mach3 I seem to remember that you need to select the correct port as well as pin - can't remember it offhand but I think it's either 1 or 10. It's in the manual. Also, be very careful with pin numbering - it's not quite what you might think! Mach3 input 10 is actually physical pin 11 on the CSMIO and its corresponding negative connection is pin 24. Again, this is all in the manual but it's easy to miss (don't ask me how I know, etc...)

[JAZZCNC]

I can't comment on the switch wire colours without a diagram in front of me, but you do need to take a wire from the -ve pin for your chosen input to the common negative - on the IP/M both sides of the inputs are floating. In Mach3 I seem to remember that you need to select the correct port as well as pin - can't remember it offhand but I think it's either 1 or 10. It's in the manual. Also, be very careful with pin numbering - it's not quite what you might think! Mach3 input 10 is actually physical pin 11 on the CSMIO and its corresponding negative connection is pin 24. Again, this is all in the manual but it's easy to miss (don't ask me how I know, etc...)

You are using NPN type switch so what you actually need to do is Take the Black signal wire to the (-) input and run 24v+ to the (+) input.
The port in Mach3 is 10 and select the input number, not the Pin number because as Neale says they are numbered differently.