Hi there, 

I am trying to setup a client monitor to run with my avid system. It is running through a black magic box, but appears as a third monitor on my Mac display preferences. 

I don't want it to be part of the os display, but simply an output monitor for the client video monitor. 

What settings do I need to adjust to get it to function simply as a client monitor for video playback, but not a 3rd OS display monitor. 

Thanks!