Remote instrumentation through the World Wide Web: A Java-controlled NMR spectrometer receiver

A new technique to control and monitor an instrument operating in a remote location is explored in this thesis. Unlike the previous methods in which the controlling computer uses dedicated software packages, this technique uses applications developed for the commonly available World Wide Web browsers to control the instrument. The instrument and the controlling host use client/server methodology for data transfer. The server runs a virtual instrument that interfaces with a real world instrument.; The virtual instrument server used is a receiver for a nuclear magnetic resonance spectrometer developed in LabVIEW 3.1. The receiver uses undersampling, a new technique for acquiring data, to sample the signals delivered by the spectrometer. With the use of undersampling, signals can be sampled at a frequency less than the Nyquist rate. To determine the signal's correct frequency spectrum, aliasing of the signal to lower frequencies that results from undersampling is used. This technique significantly reduces the number of points sampled by a receiver, which in turn reduces the workload of the signal conditioning circuits.; The client functions as a front-end of the virtual instrument to a user controlling and monitoring the instrument from a different location through the web. Java, an Internet programming language, has been used to build the client because a web browser is the only software on the client's machine needed to run a Java applet. Apart from this fact, Java is platform independent, which enables the client to work on any major operating system and still access the instrument.