Masterscan??

In TPD4 I noticed a "setup port" option labeled "Masterscan" with some sub-ports (scan list, select row 1, etc.)
I cannot find any reference as to what this may display. It would be crazy helpful if it would give me a master count like in the bottom left of Studio!
I like to know when one of our 78 masters goes offline before our patrons.

If anyone figures this out? Let me know.

Please and Thanks!