Need wiring diagram from mach3 USB breakout board to inverter.

I suppose you are trying to determine how to connect the VFD tothe relay on the breakout board. This is possible, however, not recommended as there is a more robust way to connect the VFD to mach3 or mach4 that allows that CNC machine control software to control the speed and other features of the VFD. Follow the instructions from this question (number 13383): https://buildyourcnc.com/FAQ/13383 To get to this answer, you can also ask this customer service "How can I connect my spindle's VFD to mach3?" Additional Information: If you still want to connect the VFD through the relay, I will clarify this instruction on this question tomorrow as I don't have the information in front of me at this moment. Thanks.