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National Instruments Corporation
9
NI Spectral Measurements Toolkit User Guide
The
channel specification
parameter specifies the
center frequency
,
bandwidth
, and
spacing
for the ACP measurement. The
bandwidth
parameter
specifies the width of each channel. The
spacing
parameter
specifies the separation between the center frequencies of each channel.
The
Units [rms]
parameter specifies the units for the ACP measurement.
The
Power Spectrum
parameter is a waveform graph that shows the power
spectrum with the three channels, or bands, and the power in each channel.
The
Advanced Settings
tab of the example includes some of the same
controls as the SMT Spectrum Analyzer (simulated) example, such as
Averaging Parameters
.
Using LabWindows/CVI Spectral Measurements
Examples
This section describes some of the LabWindows/CVI programming
examples located in the
<
LabWindows/CVI>\samples\smt
folder. You
can use these example programs as a starting point for your applications.
The
simulated
folder contains examples that use a simulated source. Use
these examples to explore different features of the Spectral Measurements
Toolkit without using a data acquisition device.
Continuous Zoom FFT
The Continuous Zoom FFT example is located at
samples\smt\
simulated\smtcz\smtcz.prj
.
This example demonstrates how to configure the zoom FFT, then calculates
an averaged power spectrum using the continuous zoom FFT technique.
It demonstrates how to display the spectrum in different RF units.
Frequency Response Measurement
The Frequency Response Measurement example is located at
samples\
smt\simulated\smtfqres\smtfqres.prj
.
This example demonstrates how to configure the zoom FFT, then calculates
the averaged frequency response of a stimulus and response signal from
a device under test. The example uses the block zoom FFT technique.
The example uses handles to maintain state information between functions,
such as
SmtConfigZoomFFT
and
SmtZoomFFT
.