Appendix C: RS-422 VTR Interface
Video Disk Communications Protocol (VDCP)
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Lightspeed Live Capture User Guide
Video Disk Communications Protocol (VDCP)
The VDCP interface allows an external device to control the Capture action via serial
control, where the external control acts as the server and Vantage Capture is the client.
A simple way to describe this implementation is RS-422 deck control in reverse. The
optional RS-422 hardware kit described previously provides the necessary USB to serial
control.
Making Connections
To connect to the Capture VDCP interface, connect the RS-422 output of the
automation system to one of the RS-422 connectors on the Serial-to-USB converter box
that is installed as part of the Lightspeed Live RS-422 option kit. For pin assignments,
see
RS-422 Connector Pin Assignments
covered previously in this chapter.
Communications Signal
The VDCP communications signals follow these standards:
•
Asynchronous bit serial, word serial
•
EIA RS-422A
•
Full duplex
•
38.4 kb/s transfer rate
