Based On Labwindows / Cvi Networked Virtual Instrument Software System Design And Implementation

In recent years, with the development of Virtual Instrument (VI) techniques, distributed execution techniques and network communication techniques, especially with the fast progress and popularization of Internet, it has been a wide trend for VI technologies to be incoperated with network communication techniques, which to a large extent facilitates the integration of signal acquiring, signal transferring and signal processing. At the same time, sharing of many expensive hardware resources as well as building VI systems with high falexibility and high testing efficiency become feasible.This paper first introduces the current situations of the development of VI technologies. The characteristics of virtual instruments, composition and the concept of network-based virtual instrument are then discussed in detail. The database technology, DataSocket and Multithreading which are the key technologies to realizing network-based virtual instrument are studied and analyzed. Based on the results obtained, the system-level design of a network-based VI system is fixed.Based on the analysis of the functional and performance requirements for network-based VI system, this paper design and implement a network-based VI system using three-tierd C/S model. Testing results show that the system could achieve all desired faunctionalities. This network-based VI system is composed mainly of three parts, i.e., the user-client, the equipment-client and the VI-server. This paper studies the principle of data transmission between components of the software system. It can manage users and equipments and enable a number of clients to share testing equipment, which greatly improve the efficiency of equipment use.