The DSP Lab Software consists of a set of Virtual Test Instruments designed specifically for Soft Test’s Fundamentals of Mixed Signal Testing course. The DSP Lab software is included with the “Fundamentals of Mixed Signal Testing” textbook, and is used to provide a hands-on programming experience throughout the training class. It helps visualize the concepts associated with waveform generation, signal sampling and signal analysis.
The Microsoft Windows-based software allows the student to perform interactive laboratory exercises which demonstrate the principles of Sampling, Fourier Series, Sinusoidal Waveforms, Fast Fourier Transforms, Inverse Fourier Transforms, Signal Generation and other mixed signal testing concepts.
The Fourier Series function is used to create sine waves of various frequencies. Harmonics and noise can also be added to the signal. Several predefined signals are also available for analysis. Once a signal is defined it can be viewed via the Oscilloscope.
The Oscilloscope Showing a Square Wave
The Oscilloscope is available for viewing waveforms. In this example a 1 KHz square wave is shown. Notice the fundamental and each harmonic frequency is shown in a unique color.
Signal sampling is an important step in the process of mixed signal testing. The Sampler function is designed to allow the user to experiment and visualize results, via the Oscilloscope.
The Oscilloscope showing Sample Points
This example shows the Sample Points for a 1 KHz sine wave, as defined above in the Sampler Window.
The Spectrum Analyzer
The Spectrum Analyzer displays signal data in the frequency spectrum. When used in conjunction with the Oscilloscope, a signal can be viewed in both the Time and Frequency domains. This instrument also illustrates the effects of various windowing functions.
The Sine Generator
Signal generation is an important step in the process of mixed signal testing. The Sine Generator is designed to allow the student to experiment with sine wave creation. This activity is similar to using the Arbitrary Waveform Generator of a mixed signal test system.
Waveform Generation Data Points
During the signal generation process the data points used to create a waveform can be written to a file. This data can be compared to the data points shown in the Sine Generator window. This example shows data points used to construct the signal as seen in the Sine Generator Window.
The Inverse FFT
The Inverse FFT function offers a means of creating a signal via the frequency spectrum, then viewing the results in the time spectrum using the Oscilloscope.
The Oscilloscope showing IFFT Waveform
The frequency data defined in the Inverse FFT function above is displayed in the time domain using the Oscilloscope.
Many engineers find the DSP Lab software a very effective aid in understanding the complex issues associated with signal generation, signal sampling and signal analysis. It allows the user to experiment with various test concepts and methods in a safe environment and it eliminates the need for expensive test system time. This software is included with the textbook “Fundamentals of Mixed Signal Testing” distributed in the training class, or it can be purchased separately.