The Development Of Virtual Electronic Measurement Instrument By Using The Technology Of Component

The method of software development based on component is new research and development aspect of Software Engineering. In the late 1980s, National Instruments proposed a new concept that software is instrument. It combined computer technology and modern instrument technology and developed Virtual Instrument which is a measuring instrument of totally new concept, thus it broke the restrictions of traditional instrument which is fixed structure, unitary function and poor extendibility. Virtual Instrument is a complex system which is composed of control software and hardware card and the development of its software is very crucial and complex. The development approach based on component can improve efficiency of development and maintainability. It is the best development approach of control software of Virtual Instrument.The main work of this paper is to research software development of virtual electronic measuring instrument based on component. Firstly, it proposed the definition of the component of virtual electronic measuring instrument and its structure model. Then, it proposed five combination operations of the component of virtual electronic measuring instrument and its operational rules, while it carried out a formal definition of operational rules in detail, thus established algebraic expression of software system of the virtual electronic measuring instrument. At the same time, it proposed a relationship graph of component of the virtual electronic measuring instrument. Finally, it proposed a conversion algorithm between the relationship graph of component of the virtual electronic measuring instrument and its algebraic expression.Secondly, it proposed matching thinking of component of the virtual electronic measuring instrument and matching algorithm. It selected a candidate component collection from component library by using matching algorithm and configured the candidate component collection. It proposed procedure of the configuring and the virtual electronic measuring instrument which was composed of the components of virtual electronic measuring instrument which were from configured candidate component collection satisfied the user's requirements.As sample of virtual oscilloscope and virtual thermometer, it produced required virtual oscilloscope and virtual thermometer by using proposed five combination rules in this paper to assemble the components of virtual electronic measuring instrument which satisfied the functional requirements in component library. Lastly, it described an integrated system of virtual electronic measuring instrument- Electronic Measuring Workstation in detail. These virtual electronic measuring instruments which composed the Electronic Measuring Workstation were developed by using proposed method in this paper. The experience shows that using component technology to develop virtual electronic measuring instrument is characterized as high degree of reuse, high development efficiency and flexible developed system.