Frame synchronizer
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[edit] Application
[edit] Television
A frame synchronizer is a device used in live television production to match the timing of an incoming video source to the timing of an existing video system. They are often used to "time in" consumer video equipment to a professional system but can be used to stabilize any video. The frame synchronizer essentially takes a picture of each frame of incoming video and then outputs it immediately with the correct synchronization signals to match an existing video system.
[edit] Telemetry
In telemetry applications, a frame synchronizer is used to frame align a serial PCM (Pulse Code Modulated)binary stream.
The Frame Synchronizer immediately follows the Bit Synchronizer in most telemetry applications. Without frame synchronization decommutation is impossible.
The Frame Sync Pattern is a known binary pattern which repeats at a regular interval within the PCM stream. The frame synchronizer recognizes this pattern and aligns the data into Minor Frames or Sub Frames. Typically the frame sync pattern is followed by a counter (Sub-Frame ID) which dictates which minor or sub frame in the series is being transmitted. This becomes increasingly important in the decommutation stage where all data is deciphered as to what attribute was sampled. Different commutations require a constant awareness of which section of the major frame is being decoded.
