Development of Real-Time Software Environments for NASA's Modern Telemetry Systems

Abstract

The design and development of generic, low cost, high performance telemetry components and systems require the optimum integration of custom and standard hardware elements with a number of real-time software elements. To maintain maximum flexibility and performance for Goddard Space Flight Center's VLSI telemetry system elements, two special real-time system environments were developed. The Base System Environment (BaSE) supports generic system integration while the Modular Environment for Data Systems (MEDS) supports application specific development. Architecturally, the BaSE resides just on top of a commercial real-time system kernel while the MEDS resides just on top of the BaSE. The BaSE provides for the basic porting of various manufacturer's cards and insures seamless integration of these cards into the generic telemetry system. With this environment, developers are assured a rich selection of available commercial components to meet their particular application. The MEDS provides the designer with a set of tested generic library functions that can be employed to speed up the development of application specific real-time code. This paper describes the philosophy behind the development of these two environments and the characteristics which define their performance and role in a final VLSI telemetry system.