Nevion DAC-AVA-DMUX - Manual (Page 23)

DAC-AVA-DMUX Rev. A
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Given that stable SDI input and sync input exists: If the SDI input disappears, the picture
will freeze for and then go to video generator if the card is in default
configuration.
If video input reappears
Given stable sync input, the video will reappear after of locked video input if
card is in default settings.
If sync input disappears
Given that stable SDI input and sync input exists: If the sync signal disappears, the card will
act as in frame delay mode, see chapter 4.3.5.
NOTE: This will result in a frame roll as the delay changes.
If sync input reappears
Given that a stable SDI input exists: If the sync signal reappears the delay mode will
change back to Frame Sync mode. Hence the internal clock will be locked to the sync
signal and the delay will again change.
NOTE: This will result in a frame roll as the delay changes.
If both signals disappear
The picture will first freeze for and then go to video generator. The output is
now referenced to the local clock source. However, this clock source will be kept within 1
ppm of the last sync source.
4.3.5 Frame synchronizer in ‘Frame delay’ mode
In this mode a sync signal is not present. The phase delay will now be relative to the SDI-
input. The phase delay + additional frame delay together set the total video delay.
If video signal disappears
The picture will first freeze and then go to video generator. The output is now
referenced to the local clock source. However, this clock source will be kept within 1 ppm of
the last video source.
If video signal reappears
If the input video signal reappears, the video will reappear on the output after
stable input video. The delay will be set to the same delay as before losing input.
NOTE: This may cause a frame roll.
If a sync input appears
Given that a stable SDI input exists: If a sync signal appears the delay mode will change to
Frame Sync mode, see chapter 4.3.4. Hence the internal clock will be locked to the sync
signal and the delay will again change.
NOTE: This will result in a frame roll as the delay changes.
4.3.6 Relative audio delay
An audio delay relative to the video output can be specified for all de-embedded channels
at once. This is done in Multicon GYDA. The audio delay is specified in audio samples
relative to the output video, and can be both positive and negative. The negative audio
delay is limited by the positive video delay.