Using Serial Device Control
Nearly all professional VTRs support serial device control. Serial device control sends and
receives timecode and transport control data. A 9-pin serial connector is usually used
for serial device control. Each pin can carry a separate signal, although typically only
four pins are used (two for transmitting data, and two for receiving data).
Professional video and audio decks may use one of two serial interfaces:
 RS-232: Found on older, more inexpensive equipment. RS-232 is functionally similar
to RS-422, but it’s not used as frequently.
 RS-422: This interface tolerates greater cable lengths than RS-232. It’s more widely
used by facilities where video decks are in a different room than the editing bay.