The influence of software timing error on measurement accuracy of data acquisition

摘要

The application of high-speed real-time data acquisition is becoming increasingly wide spread in industrial field, and its measurement accuracy is also increasing. The closed-loop test system of sine wave signal is constructed by the RIGOL's DG1022 dual-channel signal source, DS1102C oscilloscope and PCI7489 multifunctional data acquisition card. Three kinds of timing methods, such as Visual Basics (VB) Timer control, multimedia timer function timing and query performance frequency function timing method, were carried out a series of comparative experiments. This paper analyzes the correlation characteristics of the measured voltage peak data, which includes mean value, variance, standard deviation, range, mutation system, deviation, kurtosis and so on, and then finds out the influence rules of software timing error on data acquisition and measurement accuracy. In the high-speed data acquisition, the repeatability error can be reduced from 84.22% to 0.62%, which provides scientific basis and reference for selecting software timing method in different test environment.