External House Sync Signal

guys, I am using quadro4600 card with Gsync to sync two displays, on this page ( http://www3.pny.com/support/media//Files\89fec45d-407f-4ebe-a27d-60e466f2dace/G-Sync%20II%20User%20and%20Install%20Guide%20DU-02796-001_v01_v1.pdf) they say that we can Connect the external sync source to the BNC connector on the graphics board.

can you please help me with this, what is “external sync source signal” and HOW CAN I CREATE IT.
cheers

You need a sync pulse generator - an SPG. The signal you need is often called ‘black and burst’. Failing that, if G-Sync is flexible enough, you might be able to use a composite syncs output from a video signal.

Look for a Horita BSG-50.

Bruce Wheaton

you don’t need an external sync source signal unless you want to sync to…an external source. In other words, unless you want to sync to something your card isn’t plugged into.

Thanks guys, I think Bruce is right.
Knackered I need to sync two different devices (120hz projector and 120hz lcd) both are connected to differenct machines, so i need to use external sync source (like Bruce mentioned Horita BSG-50) with G-sync card to sync both.