Audio Precision ATS-2, Начало работы

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Quick Guide to the FFT Spectrum Analyzer
At the top of the Analyzer panel is a drop-down list of the instruments
available in ATS. Up to this point, we have been using the audio analyzer
to make measurements. We will now take a look at the FFT spectrum
analyzer . This instrument displays audio signals in time (oscilloscope-style)
and in frequency (spectrum analyzer-style). It operates in a different
fashion from the audio analyzer, as explained next.
Real-Time vs. Batch-Mode Instruments
The audio analyzer is a real-time instrument. That is, it returns readings
continuously, whether or not a sweep is in progress. These readings
include level and frequency, as well as functions such as distortion or
phase. During a sweep, readings from the audio analyzer are diverted from
the panel meters to the sweep engine for graphing. After the sweep, the
readings are once again displayed in the panel meters.
By contrast, the FFT spectrum analyzer is a batch-mode instrument. It
does not generate readings if a sweep is not being performed. When a
sweep is started, the spectrum analyzer first
acquires a segment of audio
by storing it in memory. This is indicated on the Status bar as ‘DSP
Acquiring Data’. Once the acquisition is complete, the spectrum analyzer
processes the data. This is indicated as ‘DSP Transforming Data’ on the
Status bar. Once processing is complete, ATS fetches a
batch of readings
from the spectrum analyzer. At that point, the data is graphed.
Chapter 5: Quick Guides Quick Guide to the FFT Spectrum Analyzer
38 Getting Started with ATS-2
Figure 17. Current
workspace after
amplitude linearity
sweep, showing
typical results.