The digital filter and frequency measurement based on the virtual instrument technology
Abstract：The virtual instrument which conditioning signals is gained by some essential hardware. It takes the general-purpose computer as a platform and the signal is realized through the different measurement software, such as signal’s analyze, process and display etc. It breaks traditional rule that the functions of instrument can only be defined by the factory, and the mode cann’t be changed by customers.
In this paper the conditioning signals is obtained by USB-6008 data acquisition card. With the development platform of LabVIEW software the inputting signals are mainly tested, analyzed and collected in the system. Not only digital the analysis of filtering can be achieved, but also the test of frequency is obtained. According to practical demand users can select the desired functions and design various buttons on the instrument. Domain function and frequency function domain are introduced, tested and displayed in the frequency measurement. In frequency domain the main parameters of the resonance peak, frequency, amplitude are tested. Main characteristics of time-domain, such as direct-current, positive peak value, root-mean-square are gotten. Filtered signal can be gained in the frequency, amplitude in digital filters.
Keywords：Labview；Virtual instruments；time-domain； frequency domain；digital filters；Data Acquisition
