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Brief Overview of the March 2004 (April 2, 2004) Demonstration

The "end of March" demonstration (actually held on April 2, 2004) coincides with the DOE/Lehman review of GLAST projects at SLAC, held on March 31 and April 1, 2004.

Demonstration Agenda

  • CCSDS Packet Demo
    (NOTE: This demo is rescheduled for the April 2004 session on April 30)

  • GASU Configuration Demo

  • Single Event Display Demo

  • Watchdog Demo

Goals of the Demonstrations

The demonstrations have the following goals:

  • The CCSDS Packet Demo shows that the CCSDS and CTDB software packages - required for use of the 1553 data bus and for transmission of CCSDS packets back and forth on that bus - are complete and operational. In the demo, this command and telemetry infrastructure is used to support transmission of CCSDS packets between a LAT and Spacecraft simulated in software.

  • The GASU Configuration Demo shows that the DAB and DEM software packages - required for configuring the Global trigger Electronics Module (GEM), Event Builder Module (EBM), ACD Electronics Module (AEM), and Command Response Unit (CRU) subsystems on the GASU, by writing and reading their registers - are complete and operational. These two packages also depend on a functioning LAT Communications Board (LCB) driver package, which is also used in the demo. During the demo, these packages enable a CPU crate to configure the CRU, GEM, EBM, and AEM in preparation for event taking during the Single Event Display Demo.

  • The Single Event Display Demo shows that a functioning software and hardware infrastructure for retrieving event data using the GEM, EBM, and AEM subsystems of the GASU exists. During the demonstration, a CPU crate is used to trigger the GEM manually; in response to this trigger command, the GEM and AEM send event data to the EBM, where it is assembled and returned to the crate, where it is parsed and the event data and outputs the results to the demonstration terminal.

  • The Watchdog Function Demonstration shows that a proof-of-concept design for the software Watchdog is complete, and a test implementation of this design runs on a RAD750. In the demo, the Watchdog function will detect the failure of a test task to make progress, then reboot the RAD750.