TABLE OF CONTENTS Tim Mikkelsen
All but the simplest electronic instruments have some form of embedded computer system. More and more computing is being embedded in the instrument because of reductions of computing cost and size. This is increasing computing power as well as increasing the number of roles for computing in the instrument domain. Consequently, systems that were previously a computer or PC and an instrument are now just an instrument.
This transition is happening because of the demand for functionality, performance, and flexibility in instruments and also because of the low cost of microprocessors. Embedded computers are almost always built from microprocessors or microcontrollers. In fact, the cost of microprocessors is sufficiently low and their value sufficiently high, hence most instruments have more than one embedded computer.
The instrument and its embedded computer normally interact with four areas of the world: the measurement, the user, peripherals, and external computers. The instrument needs to receive measurement input and/or send out source output. A source is defined as an instrument that generates or synthesizes signal output. An analyzer is an instrument that analyzes or measures input signals. These signals can consist of analog and/or digital signals. The front end of the instrument is the portion of the instrument that conditions, shapes, and modifies the signal to make it suitable for acquisition by the analog-to-digital converter.
The instrument normally interacts with the user of the measurement. The instrument also generally interacts with an external computer that is...
