Design And Implementation Of Configurable Data Acquisition System Based On Intelligent Instrument

In the test control system, data acquisition as a main portion provides data for test management and controlment timely, and supplies vital fact for experiment personnel doing product performance analysis. In order to shorten the development period of data acquisition system and avoid recoding, the research and design of data acquisition system has great significance.This article adopts modern software engineering idea, and connects with the reality of data acquisition on the spot, also it considers software design and system hardware structure as a whole, on the base of development experience of test control system, this configurable data acquisition system based on intelligent instrument has been designed and realized.With a view to system hardware, this article lists the main portion of the data acquisition system, this system includes industrial PC, intelligent instrument, communication interface, sensor and so on, this article briefly introduces each part, meanwhile describes the connection of data acquisition hardware in the refrigeratory test system , further brings out the general data acquisition hardware connection graph.The holistic design of system decides its performance, influences the detail design and realization. After exploring the data acquisition system on the spot, the holistic design scheme of the system is designed optimally.The function realization is considered as first goal in the earlier system design, test management together with data acquisition are realized in one application; in order to avoid the block of data acquisition, the data acquisition system is separated from the application by adopting multi-process technology, , the two programs run on one industrial PC; for the sake of meeting the demand of high-efficiency data acquisition, the whole design of the system is optimized going a step further, the test management system and the data acquisition system is separated, they run on different industrial PC, so the whole system has sufficient hardware resources to utilize and the efficiency of the system is improved greatly. Further more, this article gives the development environment, the design aim and the function analysis of the system. This article explains several key problems mentioned in the system, maily includes the research of data acquisition barrage, the use of VISA in the data acquisition system, and discusses the problem of data storage buffer, also introduces how to judge and deal with the instrument malfunction.UML embodies the idea of modern software engineering, so during the development of the system, UML is used to modeling, from the user's aspect, the case model is established, from the programmer's aspect, the static and dynamic model is given, the modeling establishes foundation for the detail design of the system.The article emphasizes the detail design and realization of the system, through practical grope, the intelligent instruments and communication interfaces in common use in the data acquisition system is concluded, and the general flow of data acquisition, basing on these, the system is designed using modularization methodology, in the part of initialization, the correlative parameters of intelligent instruments and communication interfaces are set, the introduce of INI document avoids regular modification of the program. Further more, this article explains the programme realization of the main communication interfaces, RS232/485 and GPIB, also it discusses the design and management of the database, and describes the interface between data acquisition system and test management system, at last, gives the anti-jamming measure of the data acquisition system.The data acquisition system discussed in this article is put forward on the base of household electrical appliance test, so it is universal in certain extent and can satisfy the test requirement of different household electrical appliance such as refrigeratory, air-condition,washer.