The REMOTE LOOPBACK DETECTION UNIT or RLDU is an electronic device that encodes a discrete indentifier onto an NTSC video signal. The descrete indentifier becomes an integral part of the video signal and can be transported digitally over any medium that will pass the selected field and line of video used for the indentifier. This discrete identifier is encoded onto any field of any line from line 10 in the vertical interval up to and including line 25 of the picture. Also the binary code can be reprogrammed on site without any additional equipment using the programing switch on the unit PC board.
When the RLDU receives its own signal being looped back from another location an alarm condition is detected. The alarm condition operates the video A/B switch and an audio A/B switch capable of switching the balanced mono audio signal along with other remote control features. Both normally open and normally closed contacts are available using the screw terminal connections on the unit.
This unit will eliminate video loopback latency caused by compression in MPEG/ATM networks.