Ensemble Designs 9455 3G Clean and Quiet Protection Switch - Manual (Page 6)

www.ensembledesigns.com 7435 and 9455 - page 6
Model 7435 and 9455 Clean and Quiet Protection Switches
for software upgrades and a 9-pin GPI/GPO connector for control. GPI inputs allow faults detected in
upstream equipment to contribute to the switching logic.
Avenue module parameters can be configured and controlled remotely from one or both of the
remote control options, the Avenue Touch Screen or the Avenue PC Application. Once the module
parameters have been set remotely, the information is stored on the module CPU. This allows the
module be moved to a different slot in the frame at your discretion without losing the
stored information.
SDI Signal Evaluation
The 9455/7435 monitors the integrity of the serial digital input stream and analyzes its audio and
video content. HD SDI signal health and fault detection is determined by monitoring any or all of the
following parameters, in order of increasing complexity:
• Timing Reference Signal (TRS) – This parameter checks for the persistent loss of digital sync
by looking for the correct Timing Reference Signal carried in the serial video stream. When this
digital sync format is correct, the signal is considered good.
• Black – Black detection is based on three configurable parameters: black level threshold, black
pixel count, and black duration time. All of these parameters can be set using the menu system
to meet the needs of specific video signal inputs.
• Embedded Audio – This parameter will look for correctly configured embedded audio packets
in the horizontal intervals of the signals. The actual audio content of the packets is further
analyzed to detect silence. Specific audio parameters, such as audio group, silence threshold
level, and audio silence duration can be configured in the Avenue PC and Touch Screen
menus.
• Freeze – This parameter checks for a freeze condition as determined by the settings selected
in the Freeze menu.
A sophisticated black detection system is employed to activate the switch in the event that the signal
is lost. It allows the user to select not only the threshold and percentage of black pixels, but also the
portion of the picture to be considered. The area of the picture checked is determined by selecting
Small Window which is approximately two thirds of the picture width and height, or Big Window
which covers approximately 90% of the width and height. This allows a corner Bug to be either
excluded or included in the detection process.
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 to be non-black.
Blk Frac sets the percentage of pixels which must be black in order to trigger an error. For example, if
Detect Level is set to 12 IRE and Blk Frac is set to 90%, and Blk Time is set to 3 seconds, then if more
than 90% of the pixels in each frame are below 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.