Vertical Drive is commonly used along with Horizontal Drive to synchronize monochrome or RGB video and computer display equipment. Vertical Drive marks the interval between transmission of video frames or fields.
In closed circuit video systems, vertical drive rests at 0 Volts and is active at -4 Volts. In computer video, vertical drive is active at +5 Volts.
Video Sync Separator, Sync Stripper, Sync Generator