1 or 2 dedicated 120VAC circuits for my CNC?

Use the Mist and/or Flood pins that already exist in LinuxCNC, just having those in hal will enable them and also show them in the Axis GUI.
Append the output pin to them, then in gcode adding M7 and/or M8 with M9 will happily turn on or off whatever is wired to those pins.
Something like
net coolant-flood hm2_pci-5i25.0.0.7i77.output-12
net coolant-mist hm2_pci-5i25.0.0.7i77.output-13
Edit the pins to suit your system/boards/wiring.

tommylight wrote:

Use the Mist and/or Flood pins that already exist in LinuxCNC, just having those in hal will enable them and also show them in the Axis GUI.
Append the output pin to them, then in gcode adding M7 and/or M8 with M9 will happily turn on or off whatever is wired to those pins.
Something like
net coolant-flood hm2_pci-5i25.0.0.7i77.output-12
net coolant-mist hm2_pci-5i25.0.0.7i77.output-13
Edit the pins to suit your system/boards/wiring.

Thanks Tommy. This will get me headed in the right direction. What if I am using gmoccopy? Will I have to do something different?

The gcode should work, for sure if you add those line in hal, but not sure if you get the buttons on screen.

OK so I added the following lines to my HAL file.

# external output signals
# --- ROUTER-ON ---
net coolant-mist   =>     hm2_7i76e.0.7i76.0.0.output-15
# --- DUST-COLLECTOR-ON
net coolant-flood   =>  hm2_7i76e.0.7i76.0.0.output-01


#  ---coolant signals---
net coolant-mist      <=  iocontrol.0.coolant-mist
net coolant-flood     <=  iocontrol.0.coolant-flood

I am able to see them trigger ON in Halshow using M7 & M8. I can also trigger them OFF with M9. BUT when they are triggered ON there is no power to my circuits (Output pins 15 and 01). I must be missing something. 
 

Output
hm2_7i76e.0.7i76.0.0.output-01
is the second pin on the header, not the first
just to be sure

Yes I have it correct. It is the second pin.