Design And Implementation, Remote Monitoring System Based On Virtual Instrument

Virtual Instruments is one of new technologies which is evolving with the development of computer technology. Utilizing the powerful computing capability of computer and flexible software techniques, it overcomes the limitations of traditional instruments and implements different kinds of instrument architectures demanded based on limited hardwares. In our thesis, firstly, we introduce the concepts, characteristics, principles and components of virtual instruments. Secondly, we detailedly discuss the hardware architecture and common development software of VI and then introduce the characteristics and development mode of LabWindows/CVI developing environment. At last, we implement a network measurement and control system for a two-dimension exact servant platform based on the LabWindows/CVI developing environment.The main part of this thesis is the description of a real-time network measurement and control system of two-dimension exact server utilizing the VI technology based on PCI 7344 movement control card manufactured by NI company. Through PCI 7344 movement and control card's concurrent controlling a step driver and a AC servant driver, the two drivers can drive the movement along X-axis and Y-axis directions of two-dimension exact servant platform and finally realize concurrent movement along the tow axis. Our system implement tow main functions: curve movement control and two-axis mixed sequential vector movement control. In the curve movement control functional module, the user can define the radius, original angle, movement angle, speed and acceleration of movement. In the two-axis mixed sequential vector movement control functional module, in addition to defining the speed and acceleration of movement, the user can also define the original position of every section of mixed movement. The two functional modules both can timely observe the movement track of the two-dimension exact servant platform withposition monitor.Utilizing Dynamic Link Library software technique, each of the two functional modules implemented in our system: curve movement and vector movement corresponds to a dynamic link library. And each DLL is loaded by selecting function demanded from the main control panel. Thus the system performance will be greatly improved and system workload will also be greatly decreased. At the same time, it is much convenient for the extension of system function and the generated DLLs can also be used by other programs. The system network component is implemented by DataSocket technology. That is, the program of server end will not directly communicate with that of client end, but solely load an independent DataSocket server. Server will send data to this independent DataSocket server and client will get the data from this DataSocket server. Client can show the data on a position monitor of the two-dimension movement platform and may also put the data into some files which will be used to analysis later. This kind of structure separate the workload from the server end and the independent DataSocket server is responsible for the accesses from clients to accommodate to great number of users' accesses. As considering the security factor and the current state of network communicating speed, our system doesn't implement the function of client's directly controlling the two-dimension exact servant platform.