Detecting Audio Over Level Faults; Audio Over Level; Audio Over Duration; Detecting Audio Silence Faults - evertz 7700 MultiFrame Manual

7700/7800 MultiFrame Manual
7800IDA8-3G 3G/HD/SD-SDI Intelligent Distribution Amplifier (1x8)

6.11.4. Detecting Audio Over Level Faults

The Over Level and Over Duration controls are used to detect when audio amplitude is close to a
dangerous level (i.e. clipping a downstream device, or saturating the digital word length). The Over Level
control sets the audio level over which there is considered to be a fault. The audio must be over this level
for the duration set by the Over Duration control before the fault condition exists. A fault will be generated
when any channel has generated an over condition.

6.11.4.1. Audio Over Level

The Over Level control sets the audio level over which there is considered to be over level. This value is
expressed in dB full scale (FS) and can even be used to detect digital clipping. If set to 0 dB FS, then if 3
or more consecutive samples (set with the Over Duration control) are at digital saturation (max or min),
then the digital word length has been exceeded. The value range is -30.00 to 0.00 dB in increments of
0.25 dB.

6.11.4.2. Audio Over Duration

The Over Duration control sets the duration, in number of consecutive samples that are at or above the
Audio Over level before a fault condition exists. The value range is 3 to 255 samples in one-sample
increments.
Note that as longer durations are configured, you are eliminating the detection of higher frequency content
over the set Over level.

6.11.5. Detecting Audio Silence Faults

The Silence Level and Silence Duration controls are used to detect when the audio is considered silent.
The Silence Level control sets the audio level under which the audio is considered to be silent. The audio
must be under the Silence Level for the duration set by the Silence Duration control before the fault
condition exists. When the fault condition exists, the audio must be over the Silence Level for one second
before the fault condition will be removed.

6.11.5.1. Audio Silence Level

The Silence Level control sets the audio level under which it is considered to be silent. This value is
expressed in dB full scale (FS). The value range is -80.00 to -45.00 dB in 0.25 dB increments.

6.11.5.2. Audio Silence Duration

The Silence Duration control sets the length of audio silence, in seconds, before a fault occurs. The
value range is 0.5 to 127.0 seconds in 0.5 second increments.

6.11.6. Detecting Video Level Problems

The active video picture is analyzed for content that is whiter than it should be and/or blacker than it
should be. Faults can be configured to fire when these conditions exist.
The active video picture is also analyzed for content that does indeed vary between low levels (near black)
and gray levels (below white). If the video does not reach near black or does not go towards white for
some defined period, the video content and/or upstream processing may be in error. Faults can be
configured to capture these conditions.
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