National Instruments 373873C-01 用户手册

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You can use LabVIEW SignalExpress to automate measurements to 
characterize and validate designs by creating sweep operations. You can 
use the sweep measurements to gather data from designs over a range of 
conditions to document the performance of the designs. For example, you 
can use sweep operations to vary the frequency of a stimulus signal or vary 
the level of a supply voltage while taking measurements to characterize 
designs.

This chapter teaches you how to set up sweep operations using the Sweep 
step in LabVIEW SignalExpress. You learn how to characterize the 
performance of a filter by sweeping through a range of frequency values 
and measuring the output of the filter. You also learn how to display sweep 
results and perform multidimensional sweeps for more complex 
measurements.

You can use the Sweep step in LabVIEW SignalExpress to define 
automated measurements for complex, repeatable sweep operations.

Complete the following steps to define a frequency range in a sample 
project to sweep through a filter.

1.

Select File»Open Project, navigate to the 

SignalExpress\

Examples\Tutorial

 directory, and double-click 

Sweep.seproj

.

2.

Click the Run button, shown at left, to run the project.

The project generates a sine wave stimulus signal using the Create 
Signal step, passes it through a bandpass elliptic filter using the Filter 
step, measures the RMS level of the filter output using the Amplitude 
and Levels step, and converts the level to decibels (dB) using the 
Formula step. The Filter step acts as a simulated unit under test, so the 
project uses no hardware. However, you also can sweep physical 
signals generated from a National Instruments arbitrary waveform