To Set a Video Mode
If you are using an external reference, ensure that a proper reference is connected to the REF IN input BNC on the frame.
Note: You must use an interlaced reference source to have the switcher operate in an interlaced reference format if you
            are using an external reference.
      - Click Navigation Menu > Configuration > Reference.
- 
            Click the Video Mode button and select the video format you want to use. 
            The available video modes depends on the reference format coming into the switcher. 
- Click the Reference Source button and select an internal or external reference source.
