Ensemble Designs 7160 Serial Digital Protection DA - Manual (Page 4)

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Model 7160 HD/SD/ASI/310 Protection DA
MODULE OVERVIEW
The 7160 Serial Digital Protection DA module is a fail-safe bypass protection switch for monitoring and
switching critical SD and HD paths in broadcast and satellite applications. When a fault is detected in
the Primary input, the switch will activate, causing the Secondary (backup) input to be switched to the
module’s distributed outputs. The switch can operate in two modes; automatic or nonresetting.
The 7160 monitors the integrity of the Primary serial digital input stream and analyzes the audio
and video content. Signal health and fault detection is determined by monitoring any or all of the
following parameters: Closed Caption Data, Timing Reference Signal (TRS), Black, Embedded Audio,
Error Detection and Handling (EDH), CRCs, and Freeze.
A sophisticated Black detection system is employed to activate the switch in the event signal is lost.
It allows the user to select not only the threshold and percentage of non-black pixels, but also the
portion of the picture to be considered.
The Freeze detection system can be set to detect a clean or noisy source. Freeze Time sets the number
of seconds that can elapse before the 7160 switches to the secondary input after a video freeze
condition is detected in the primary input.
SDI Signal Evaluation
The 7160 monitors the integrity of the serial digital input stream and analyzes its audio and video
content. Signal health and fault detection of SD SDI and HD SDI signals 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 signal is lost.
It allows the user to select not only the threshold and percentage of non-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.