Automatic data acquisition system for an LED test

The object of the work performed was to develop a computer controlled data acquisition and data analysis capability For an uninterrupted 6,00o hour test to monitor the degradation of approximately 250 infrared light emitting diodes (LED's). The test program comprised subjecting a sampling of 254 diodes to preselected constant currents and temperatures while periodically measuring the voltage drop and the light output of each of the diodes. To perform the data acquisition portion of this effort, an automated data acquisition system was designed around a Hewlett-Packard 2l00A computer. This system utilized a 1,000 point random access multiplexer, a l6-bit Relay Output Register and a digital voltmeter for data acquisition and transmission. Special purpose assembly language input/output routines were written for the computer's BASIC Interpreter to make this special equipment accessible to the computer. The Control program handled data storage to meet the requirements specified for the project.