Towards an Internet-based virtual-wire environment with virtual instrumentation

An Internet-based virtual-wire application that uses virtual instrumentation to achieve a continuous control of a closed loop control system is presented. The system acquires data from remote signal sources and publishes them via the Internet in the real-time, while enabling the remote user to send control signals from the web-browser to the server application for the control of a PID based control system. The system involves the development of the server application using LabVIEW graphical programming language and the client application, which is a Java Applet embedded to a HTML format. Problems and limitations of achieving stable continuous control of the system by the remotely located computers are discussed. It was found that continuous control of a real time system via the Internet is possible, but a sustained virtual wire application with the current limitations of Internet technology is impossible.