Research On The System Of Virtual Instrument In Theory

With the development of science and technology, the requirement on measurement technology is getting more and more important. The application of electronic measurement technology has extended to more fields than before. Because of limited functions and big size, traditional electronic measuring equipments are no longer suitable to common purposes. The rapid development of integrated circuit and computer technology gives birth to a new kind of instrument, Virtual Instrument (VI). Compared with traditional equipment, VI characterizes with more functions, higher processing speed, wider bandwidth, friendlier interface, small size and better expandability. It is based on PC platform, which not only make it convenient to use the software and hardware resources of PC but also g-et the ability of data processing flexible. A measure system can be easily builded for various requirements by VI.In this article, VI is studied theoreticly, which involves software criterion, exploitation tools, hardware forms and its design rules. In our country, personal computers are being used widely, so a kind of data acquisition system based on VI is put forward, it not only has a good quality as well as expensive instrumme-nt, also can fulfill various measurement. Therefore this kind of data acquisition system based on VI is very fit our country in measurement. With regard to software, it's design approach and idea are discussed particularly. This article brings forward the idea that when we design a VI we should unify instrument criterion.Because the technology of data acquisition and data processing is very imp-ortent, this article study the technique of gathering data and it's system design. When we gather data, we often fell the gathering speed is slow, the precision of A/D transition is bad and other problem, based on the gathering theory, this dissertation put forward relevant resolving project.The development of network makes long-distance measurement and control possible. In this dissertation, the technologies of DDE, DataSocket, DCOM/Ac-tiveX are also described. Three methods based on these technologies described above are applied to remote control and measurement system. System structureand working principle are discussed in particular. It offers a short cut for the long-distance measurement and control.