I'm not sure that I understand your question 100%. This procedure will make the MASTER VOLUME knob only control the MONITOR output, the main outputs will be at a fixed level.
Press the OUTPUT button.
Go to page 2/7.
Uncheck Main Out Link.
Check Monitor Out Link.
Set the Main Volume to something like -14.6dB, that's where I run mine but you might need to adjust it to work with your PA.
Don't worry about the Monitor Volume, it will be controlled by the volume knob.
Press the SYSTEM button.
Go to page 3/11.
Set the Vol. LED Collar to Monitor Volume, this will make the LED's around the volume knob match the monitor output setting.
I'm very interested in this. Can yo elaborate on this? "This procedure will make the MASTER VOLUME knob only control the MONITOR output, the main outputs will be at a fixed level."
If I understand this right, I can control my on stage FRFR cab with the MASTER VOL knob....but how to I control FOH volume?