A microcomputer interface for decoding telemetry data and displaying them numerically and graphically in real time

Abstract

A microcomputer (IBM-PC) interface for decoding ultrasonic telemetry pulse-modulated signals from either unisensor or multisensor (time-multiplexed) transmitters is described. Pulse intervals, recorded by the interface, and corresponding independently measured parameter levels (i.e., swimming directions, speeds, depths, water temperature, and ambient irradiance levels) are entered into a calibration file. The IBM-PC uses this file to convert the signal's pulse intervals to sensor states and displays these in real time. States of up to eight multiplexed sensors can be displayed concurrently in either numerical or graphical format (as histograms) with low resolution (16 axis divisions) or, for a particular sensor, with high resolution (70 axis divisions). The circuit components mount on the IBM Prototype Card (with foil for interfacing logic) allowing easy installation in the IBM-PC's expansion slot. The 35K of controlling software is written in Pascal with four subroutines in assembly language. © 1987 Psychonomic Society, Inc.