Albalá Ingenieros DAR3000C01, Manual, Page: 22 / 32

Albalá Ingenieros | Manual DAR3000C01
configuration of the module is restored.
The tone generator level of the DAR3000C01 can be set to 0 dBfs, -18 dBfs or -20 dBfs
for all of the outputs. This level selection is done via the microswitch bank S1 of the
module and from a computer if a communications controller is installed in the same
mounting frame as the DAR3000C01. Selection of those outputs that generate a tone
can only be done via the computer and remote control software. The tone frequency
can be 400Hz or 1kHz and can be adjusted independently for the L and R channels of
outputs 1 and 2 and for the L and R channels of outputs 3 and 4. The frequency used is
only selectable via the computer and control software.
The DAR3000C01 comes from the factory programmed to generate silence at outputs
1 and 2 and a tone of 1kHz at outputs 3 and 4. The default amplitude of the
generated tones is 0 and -18 dBfs, depending upon the settings of the configuration
switches of the module. It is important to keep in mind that these tones are
synthesized based upon the sampling frequency, and therefore in varispeed mode the
frequency synthesized is provided by the following formula:
f
tone_nom
is the nominal frequency for the tones that the module can generate and is
either 400Hz or 1kHz. f
ref
is the sampling frequency of the AES/EBU reference signal
entering the module and f
tone
is the actual frequency of the tone being generated.
Another feature of the DAR3000C01 is the insertion of short periods of silence, or dips
into the generated audio tones in order to identify the channels. These dips are
repeated every ten seconds and last for one-half second each. The pattern followed by
each channel of the digital audio stream is shown in the following figure. Also
displayed is the sum and difference of both channels when they use a signal with the
same frequency and phase, since it is easy to determine if a monophonic signal has
been generated correctly. Note that in the case of summation, the resulting
amplitude is twice that or the original signal (6dB greater).
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