DSP-Based Multipurpose Instrumentation

Abstract The paper illustrates the development of low cost multichannel digital instrumentation for real-time control applications. The realization is based on the use of an advanced digital signal processing chip, providing the necessary computing power and processing throughput. Algorithms perform Discrete Fourier Transform spectral analysis of the incoming signals and further process data to compensate for the effects of spectral leakage. A variety of parameters can be obtained with good accuracy from the knowledge of signal spectra simply by adopting different computing routines. The application of a two channel instrument in the monitoring of electrical power under nonsinusoidal conditions is considered, and results are given for the case of linear loads. Absolute measurement errors are of the order of 10-4-10-5, while a sampling rate in excess of 200kHz per channel is achieved. The structure of the instrument is very simple, and only standard devices are needed to realize it. As a result, it is well suited as a low cost and flexible measurement block in control systems.