NVIDIA frame sync-capable graphics cards support the following external house sync signal types:
TTL (3.3 volt level)
Composite Bi-level (NTSC or PAL sources use bi-level composite signals.)
Composite Tri-level (HDTV sources commonly use tri-level composite signals.)
Normally, the software automatically detects the signal type that is being used. If the driver fails to detect the signal type, you can force the software to detect the signal type as follows:
On the system that you have set up to be the server, go to the NVIDIA Control Panel Workstation page and click Synchronise Displays.
Click Edit Settings to open the Server Settings dialogue box.
Click the Sync signal detection list arrow and then click the item corresponding to the house signal source.
Click OK to save the settings.