Research On Data Transmission, Display And Processing Of Signal Acquisition System

With the advancement of science and technology, the development of measurement technique is getting more and more important. The application of electronic measurement technique has extended to more fields than ever. Due to limited functions and big size, traditional electronic measurement equipment is no longer suited for common purposes. Thanks to the rapid development of integrated circuit and computer technology, measurement instruments are becoming digitized and intelligentized. Compared with traditional equipment, the new instruments have more functions, higher processing speed, wider bandwidth, friendlier interface, smaller size and better expandability. The prevalence and rocketing development of personal computers give birth to a new kind of instrument, Virtual Instrument (VI). VI is based on PC platform, and can make use of the software and hardware resources of a PC. Compared with its ability of data processing and flexibility, VI has a low price, which means it is a good choice for research and teaching reform in universities. This dissertation discusses the implementation of a signal acquisition system, based on the concept of VI. With a self-developed data acquisition card connected to PC, a digital storage oscillograph (DSO) with the function of cymometer and spectrum analyzer is developed. The usage of LabVIEW, the specialized VI software platform, gives the system more flexibility and wider application. This dissertation focuses on key techniques in data transmission, display and processing. The main elements of this dissertation are as follows: developing LabVIEW instrument driver using Windows dynamic link library (DLL), combining real time and equivalent time (NT ?A T) sampling methods in signal acquisition, adoption of minimum mean square error (MMSE) method to synchronize signal displaying, realization of spectrum analyzer in LabVIEW and solutions to the noises possible to appear in the system.