National Instruments 373873C-01 Performing Sweep Measurements

Performing Sweep Measurements

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