Ensemble Designs 7160 Serial Digital Protection DA - Manual (Page 5)

www.ensembledesigns.com 7160-5
Model 7160 HD/SD/ASI/310 Protection DA
Black detection is performed on a pixel-by-pixel basis within the selected window, with user selectable
Detect Level and Blk Frac adjustments. Pixels above the Detect Level are considered as being non-
black. Blk Frac sets the percentage of pixels which must be non-black. If Detect Level is set to 12 IRE
and Blk Frac is set to 10% then the 7160 expects there to be pixel levels above 12 IRE for more than
10% of each frame. For example, if Blk Time is set to 3 seconds, if less than 10% of the pixels in each
frame are above the selected 12 IRE level for a period of 3 seconds, a switch will occur.
Pri Valid and Sec Valid are dynamic values based on incoming video. In the above example, if Pri
Valid fell below Blk Frac continuously for 3 seconds there would be a switch, provided that there
is valid secondary video. Note however, that the display may not keep pace with short duration
transitions of actual video. In the example, an excursion above 12 IRE for a single frame every 2
seconds would not cause a switch to take place, since the 3 second count would be reinitialized by
these valid frames.
DVB-ASI and SMPTE 310M Signal Evaluation
For DVB-ASI and SMPTE 310M signals, there are two levels of signal analysis available: Simple or
Advanced. Use the ASI Test control in the Config menu to choose between these.
When ASI Test is set to Simple, the 7160 looks for:
Input signal presence and digital clock lock •
Presence of non-null (blank) packets •
Presence of Program Allocation Table (PAT) PIDs occurring at least two per second •
When ASI Test is set to Advanced, the 7160 looks for the above conditions, plus the following:
The presence of at least one program stream being called for in the PAT. The 7160 can •
automatically look for the first one, or the user can tell it which of the first four it should look
for. This selection is made with the Pgm Target control in the ASI Config menu. The 7160
expects at least one Program Management Table (PMT) PID per second.
The targeted Program must contain at least one elementary Video Stream and one elementary •
Audio Stream.
A user-defined minimum number of video packets each second in the Video PID. •
A user-defined minimum number of audio packets each second in the Audio PID. •