Research Of Experiment System Based On The Virtual Instrument

The experiment places an important role in the science subjects teaching, which is the necessary part of the teaching activities, we can say that the experiment is the foundation of the science subjects curriculum teaching, it can strengthen the interest of learning, deepen the understanding of the theoretical knowledge, train the skills of practicing, the ability of designing, identifying ,analyzing and solving the problems in the experiment, what's more ,raise the ability of innovating and exploring and the spirit of team association.The experiment teaching is very important, however there exist many defects in the hardware experiment model base on traditional instrument, among which one is the equipment's long cycle of updating, and the difficult maintenance work; the second is the fixed function of the traditional experiment Instrument, with the poor feature of operation and expansion. another is the lack of the flexibility in the laboratory management, as to the waste of resources is serious and the utilization of experiment instrument and equipment is not high, the way of organization and management pattern of experiment teaching are lagging far behind. The phenomenon of none experiment teaching or theory and practice are not matched is very common in modern distance education. Therefore, developing the experiment instrument, innovating the methods and pattern, optimizing the teaching objectives and experimental model of integrated strategy, reforming experimental teaching continually are the key points.In the aspect of experiment instrument development, the virtual instrument technology is worthy of our attention, which is product of the combination of computer technology and experiment equipment technology, it urges the traditional instrument to develop into the digitalization, modulation, and network. Virtual instrument is a instrument system based on computer, it makes use of PC monitor's display function to imitate the traditional instrument function surface and uses the function of PC keyboard and mouse to control and drive the kinds of software buttons, and uses the PC application software to achieve the operation, analysis, storage of the data (signal) ,uses I/O equipment to complete the gathering, transforming, adjusting of the data (signal), to achieve the functions of the instrument. Virtual instruments are designed and produced according to the users' own needs, the analysis ,demonstration, memory, printing and other operations of the signals of which is handed over to process by the computer, the combination of virtual instrument technology and web technology, based on which the remote control experiment can be achieved. Bringing the Virtual experiment into the teaching will become the important way of the school teaching research.At the same time, the author considers that the base goal of college experiment teaching is narrow, the advanced goal is general and the experiment pattern is single. The science Experiment teaching should constitute a system of Multi-dimensional goals,taking the scientific literacy as the general objective, taking the experiment skills, the ability of operating, testing, designing, exploring and innovating and cooperating in the procedure of experiment as the concrete aim. the Experimental model can be divided into four kinds : demonstration experiment, hardware experiment base on traditional instrument, simulation experiment, and the control experiment based on virtual instrument, and the function and form of which are different, the integration strategy of goal and the pattern is different too.Besides the above theoretical study, the author also made three designs, one is the synchronous temperature control system based on virtual instrument by using the USB2.0 multi-function data acquisition card, the working principle of temperature control and light and sound alarm is: the temperature signal is given by the sensor AD590K and signal adjustment circuit and sent to the data acquisition cards, and then gets to the computer to display and record; Second is the RC transient state experiment system based on the virtual instrument, which makes the soft-switch control and soft-panel' signal display come true; Third is the produce of a set of experiment platform based on the B/S mode, and the main modules are: the teacher management module and the student experiment module.