The Research Of A Multitask Measurement And Control System And Its Database Based On LabVIEW

As the G language graphical development tool for implementing Virtual Instrumentation(VI), LabVIEW has been developed by National Instruments company. It has a broad range of application and powerful function. But for the present, most of its applications are used to build Virtual Instrumentation based on a PC. And only some parts of it functions are used, such as data acquisition, handling, and presentation. The users ignore that LabVIEW has a surpassing ability to construct a powerful control system. At present, PC-based real-time measurement and control system is one of the important developing directions of real-time systems. This thesis expands my research, and an IPC real-time measurement and control system based on LabVIEW, which is centered on improving real-time performance and solving the multitask problem.This thesis firstly analyses the usage of programming language and introduces a software–RTX which can expand Windows system into real-time system.Then, the task and schedule of real-time system are discussed. The real time and multitask are the two important features of the computer measurement and control system. Scheduling the real-time multitask is the key to ensure that the system runs normally .As a solution of multitask scheduling, a scheme of two level-task-queue is provided, the task scheduling kernel is also developed. LabVIEW is successfully applied to a practical industrial real-time measurement and control system. The hardware building and software coding are implemented. The tasks are divided into real-time tasks and normal tasks in the system. All works are well done, including the data acquisition, handling, saving, outputting, displaying and management.Some network communication mechanisms of LabVIEW, including TCP/IP functions, UDP technology are analysed. G programs based on TCP/IP protocol are developed. Build on a small distributed monitor system through the LAN network on the basis of the IPC real-time system is discussed.Lastly, this thesis researches the real-time databases. The network communication functions discussed above and the database interface tools are used to build up a database management system which belongs to an IPC real-time system. So, the raw data is acquired into the database, and the dada can be polled, analyzed and distributed.Research results show that it is possible to apply LabVIEW to an industrial measurement and control system,the performance of a real-time measurement and...