Microprocessor-Controlled Time-Sharing Services Terminal with Interfaces for Instruments and Its Application to Precision Measurement of High VSWR

Abstract

This paper describes a data entry terminal controlled by a minimum system of a microprocessor. The terminal is designed to be used specifically with measuring instruments. It is portable and may be used conveniently for the laboratory automation purposes. This terminal has interfaces for measuring instruments, and for a large-scale general purpose computer to utilize time-sharing services (TSS). The hardware for this terminal is installed on a single board, and the software is implemented into the ROM of approximately 2 kB. The specific features of this terminal include 1) that data aquisition and data transmission to the center computer are concurrently done, and 2) that a data reduction scheme is introduced to compress the amount of data up to 40 percent. The data compression is made possible during the microprocessor's idle time. The designed real-time data entry and processing system is applied to the precision measurement of a high voltage standing-wave ratio (VSWR). The concept of a distributed VSWR is introduced, and the multipoint redundant technique is adopted in order to succeed in the reasonable precision measurement of the high VSWR.