The c11g doesnt have a control side input for the relays. The control side is built-in via printed circuits. No wiring necessary.
Ill assume in mach 3-ports and pins-spindle, youve set cw rotation to output 1 and ccw rotation to output 2, set it to pwm, with a base frequency of 300.
Then in mach 3-ports and pins-outputs, youve set output 1 to pin 14, port 1. And that youve set output 2 to pin 16 port 1.
And that in mach 3-ports and pins-motor outputs youve set your spindle output step to pin 14 port 1, and dir to pin 16 port 1.
If the jumpers are set to US mode, and mach 3s spindle turned on in clockwise direction, mach 3 output 1 is activated and outputs a pwm signal to pin14. The presence of a pwm signal from mach 3 on pin 14 triggers relay 1. Nothing happens on pin 16 or relay 2.
With the jumpers set as above, in US mode, and mach 3s spindle tured on in counterclockwise mode, output 2 is activated and pwm is still sent out pin14, but ONLY relay 2 is triggered.
So, basically, with the jumpers set to US mode, cw spindle on triggers a pwm signal on pin 14, and relay 1 only.
Ccw spindle on in mach 3 activates a pwm signal on pin 14, and triggers relay 2 only.
So, that being the case, when you turn on cw spindle rotation, as in an m3 command, you will get output 1- a pwm signal out pin 14 which turns on your analog voltage output to drive your vfd. You will also activate relay 1, which should be wired to close your vfd signal common to your enable (sometimes called start/stop).
When you turn on ccw spindle rotation in mach 3, youll get the same pwm signal on pin 14 which will drive your vfd. Youll also get output 2-pin 16-relay 2 triggered, which should be wired to close your vfd signal common to the reverse/forward wire. On my vfd the reverse wire closed to sig common makes it run backwards. The reverse wire left open makes it run forward.
My vfd must have the signal common closed to the enable for cw rotation, and must have the signal common closed to both the enable AND the reverse for ccw rotation. So, i have my jumpers set to International mode.
With the jumpers set to international mode, m3 activates pwm and relay 1 only (closing my sig common to enable). Ccw spindle (m4) activates BOTH relays ( relay 1 closes my signal common to enable ) and (relay 2 closes my signal common to reverse).
How you wire it depends on the type of vfd/controller running your spindle motor.
Tell me what kind of vfd/controller your using and ill do up a wiring diagram.