Unclamp and Clamp Spindle

[David Buchhauser]

I'm trying to get one of the atc macros going for my spindle. For manual tool change, I simply push a button to energize the solenoid valve that supplies air to the spindle for clamp and unclamp. Now I wish to unclamp and clamp under program control. I have output 8 configured as "Unclamp Tool" (see photo). Using MDI I issue the M15 command to unclamp tool and the output 8 relay clicks and the led turns from red to green. So far so good. Now I want to turn the output 8 relay off. I use MDI to issue the M16 command and nothing happens. How do I turn off the output 8 relay?
Thanks,
David

[David Buchhauser]

OK - I figured out that I can use M94/68 to turn output 8 ON, and M95/68 to turn output 8 OFF. For my application output 8 ON = unclamp spindle, and output 8 OFF = clamp spindle.
I am editing the mfunc6 macro. If I replace the M15 (unclamp spindle) command with M94/68 and replace the M16 (clamp spindle) command with M95/68 then I believe that this will accomplish what I need. Does this seem logical, or is there a better approach?
Thanks,
David