USING DSPS TO BUILD MODULAR DATA-ACQUISITION AND INSTRUMENT CONTROL-SYSTEMS - SHIFTING FUNCTIONALITY FROM HARDWARE TO SOFTWARE

A low-cost data-acquisition and instrument control system based on digital signal processors (DSPs) has been constructed for use with an instrument using an infrared array. By using off-the-shelf components, system design was simplified, construction time and cost were reduced, and reliability was increased. Readout time for an 11X64 array is 3.5 ms. Faster readout times are easily attainable by using DSPs with higher clock speeds. The use of DSPs shifts much of the functionality (and the development work) from hardware to software. The acquisition software is a distributed system running on two Sun SPARC stations and two DSP cards containing Motorola DSP56001s. The data-acquisition software takes advantage of the object-oriented features of C++ to modularize the software system. This simplifies the DSP and telescope interfaces and the implementation of a variety of observing modes. The modularity of this system allows it to be easily adapted to other telescopes and/or arrays.