A Small Laboratory Automation System Composed of Microcomputer-Based Spectrophotometers

Abstract

A distributed microcomputer network system which consists of integral microprocessors in intelligent instruments has been developed for automating the spectroscopy laboratory. In this system, the master-slave arrangement of microcomputers is adopted to compose the system controller and three microcomputer-based spectrophotometers (an UV/visible spectrophotometer, an IR spectrophotometer, and a fluorescence spectrophotometer). The IEEE-488 standard interface bus is employed for the hardware compatibility of the communication between the system controller and spectrophotometer subsystems. The Tiny BASIC language is modified as a standard language in the system for real time execution along the communication through the IEEE-488 interface bus. The operation includes two modes: the local mode and the remote mode. In the local mode, the spectrophotometer is manually controlled independently from the system controller. In the remote mode, the modified Tiny BASIC program controls individual spectrophotometers. The program is written by the user at the system controller and is loaded down to the microcomputer of a spectrophotometer subsystem. This program is executed via the individual modified Tiny BASIC interpreter implemented in the subsystem. The system structure, design of the modified Tiny BASIC, and operating procedures are presented together with typical performance data.