All the features of our popular AFS-3 Audio Failsafe available to video broadcasters.
Trigger alert or terminate transmission on loss of video
The VFS-1 Video Failsafe monitors a composie video input signal and maintains a relay contact closure as long as video is present. When the video signal is lost for a preset length of time, the relay contacts open and remain open until video is present again. To eliminate false triggering, video must be lost for a preset length of time. The length of this delay is adjustable from 5 seconds to 50 seconds in five second increments.
The VFS-1 is typically used as an alternate control for a broadcast transmitter. When properly installed, the VFS-1 can turn off a transmitter by stoping the video feed to the transmitter. This procedure would normally be used only when the normal control system has failed. Alternately, the VFS-1 can supply a logic-level voltage to an outboard piece of equipment, such as a transmitter remote control, that can respond to the alarm condition and contact station personnel.
The VFS-1 is housed in a small metal chassis that is attached to a single rack space size panel. It is designed for mounting in a standard 19” wide equipment rack. All connections are made through pluggable connectors on the rear panel. The video input accepts NTSC composite video on a standard RCA phono type connector. Front panel indicators include power, system enabled, video present and alert status. Controls include a front panel defeat switch, rear panel delay adjustment and internal jumpers to select options such as an audible alert (Sonalert) and logic voltage on the ouput relay. Both normally open and normally closed relay contacts are available.
Much like our Audio Failsafe, the VFS-1 Video Failsafe features:
- Internal Sonalert audible alert--continuous or pulsing
- Positive delay adjustment via rotary switch
- Delay adjust accessible on rear panel
- Logic-level alert voltage built in
- Video detect mode
The VFS-1 also works in reverse as an video detector instead of a loss-of-video detector. Normally a delay period of no video is necessary to trigger an alert. In reverse, a preset period of video present can be used to trigger an alert.
