I'm using the C10 BOB and I have the option to wire my Estop as an input to Mach3, which I always did before, or as hardware disable.

I understand that the hardware disable will cut all outputs to the machine but I don’t understand why I need both.

Perhaps is a double safety?

One is soft and one is hard. In one case you are you take away the power in case of  an emergency,like shuting the whole machine down. In the soft case you are stopping the program using software which is not failproof.

FWIW, my estop takes the voltage away from the opto's, and when applied, all axis stop INSTANTLY, of course the program continues to run but there is no movemement of the axis.

RICH

Thank you RICH, I was not sure but now its clear