Data display method and apparatus

Abstract

A digital instrument is represented by an analog-to-digital converter 17 controlled by a CPU 10 to effect measurements at regular intervals. The digital measurements are stored in a history file in a RAM 14, e.g. the most recent 100 or 500 measurements. The measurements are also linearly processed by rounding and range scaling to produce 100 reduced measurements in a second file in the RAM 14. This file is cyclically read out to a digital-to-analog converter 18 to produce a voltage on a terminal 22 for application to an oscilloscope which provides a display from which features of the measurements (e.g. a trend or a periodic component) can be seen. In order to allow for flyback and reset the 100 reduced measurements are held in a file of larger capacity (e.g. 130 or 150 measurements) which is cyclically read out. As the oldest of the 100 measurements is read a driver 19 provides a trigger pulse on a terminal 23 for the oscilloscope external trigger input. Various linear and non-linear algorithms for deriving the second file from the history file are described.

Dependencies are inferred from the claim text.