The Front End Processor (FEP) Real-Time Embedded Software performs command and data-processing functions for an aeronautical MIL-STD-1553B telemetry link and ground support equipment (GSE) in a spacecraft-equipment-testing environment. The FEP is used in the Test, Control, and Monitor System of the Space Station Program for checking out Space-Station modules and payloads as they flow through Kennedy Space Center. Consisting of about 50,000 lines of C-language code, the FEP software runs on Motorola MVME 167 processors in a VersaModule Eurocard (VME) chassis. The software can be re-compiled for execution on other processors. The software interacts with the 1553B telemetry link through commercial VME interface cards and supports as many as four redundant 1553B buses. The GSE interfaces consist of analog, digital, relay, and serial links for controlling the GSE used in testing. The software includes modules that control and monitor the MIL-STD-1553B links of the Space Station and the associated GSE interfaces. Back-end interfaces (user interfaces) to the FEP software are provided through a standard Ethernet network that enables a user or a testing application program to exercise control or to monitor data from the interfaces supported by the FEP software.

This program was written by Thomas L. Herring, Richard B. Arnold, Christopher S. Forney, Eric J. Schafer, Berta A. Alfonso, Wyck C. Hebert, Jeffrey S. Vickers, Pamela A. Meier, Jose A. Marin, Andrew E. Wheeler, and Chau B. Lee of Kennedy Space Center. For further information, access the Technical Support Package (TSP) free on-line  under the Software category.


NASA Tech Briefs Magazine

This article first appeared in the November, 2001 issue of NASA Tech Briefs Magazine.

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