Hi .
I want to start and stop my spindle from G code program using  mach 3 mill , I have a C11 breakout board from cnc4pc and the spindle motor is connected from that  relay  Pin 1. What do I need to set up in Mach 3 spindle set up to get this to work.
Regards
Eric

Dont know anything about the C11 board but usually you will have to set up the output pin numbers for the relay you are using, you will find this in Ports and Pins, spindle setup.
 If you can give more details about the motor and whether you have a VFD or ?
Hood