Table of Contents
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Chapter 5
Step 2-Configure the Octave Analyzer .......................................................................5-3
Configuring Your Octave and Level Measurement ........................................5-3
LabVIEW Examples........................................................................................5-4
C Example .......................................................................................................5-5
Step 3-Read Octave Measurement ..............................................................................5-5
LabVIEW Examples........................................................................................5-7
C Examples......................................................................................................5-7
Step 4-Control .............................................................................................................5-9
Chapter 6
FFT Analyzer .................................................................................................................6-1
FFT Measurements..........................................................................................6-2
Dual Channel FFT Analysis ............................................................................6-5
Baseband and Zoom Frequency Spans............................................................6-7
Swept-Sine .....................................................................................................................6-15
Why Swept-Sine Measurement? .....................................................................6-15
Swept-Sine Controls and Settings ...................................................................6-17
Swept-Sine Measurements ..............................................................................6-20
© National Instruments Corporation
Alias-Free Bandwidth .......................................................................6-7
Classical and Extended FFT Size......................................................6-8
Baseband Spans.................................................................................6-8
Zoom Spans.......................................................................................6-9
The Real Time Zoom FFT Process.....................................6-9
Zoom Span Characteristics .................................................6-11
Windowing........................................................................................6-12
FFT Averaging ..................................................................................6-14
Averaging..........................................................................................6-17
Sweep Frequency and Auto-Resolution............................................6-17
Input Auto-Ranging ..........................................................................6-18
Source Auto-Level and Ramping......................................................6-19
Spectrum ...........................................................................................6-20
Cross-Spectrum ..................................................................6-20
Frequency Response ...........................................................6-20
THD - Total Harmonic Distortion ......................................6-20
SINAD ................................................................................6-21
Swept Harmonics................................................................6-22
RMS Squared......................................................................6-22
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Contents
NI-DSA Software User Manual
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