25 July 2014 A traffic analyzer for multiple SpaceWire links
Author Affiliations +
Modern space missions are becoming increasingly complex: the interconnection of the units in a satellite is now a network of terminals linked together through routers, where devices with different level of automation and intelligence share the same data-network. The traceability of the network transactions is performed mostly at terminal level through log analysis and hence it is difficult to verify in real time the reliability of the interconnections and the interchange protocols. To improve and ease the traffic analysis in a SpaceWire network we implemented a low-level link analyzer, with the specific goal to simplify the integration and test phases in the development of space instrumentation. The traffic analyzer collects signals coming from pod probes connected in-series on the interested links between two SpaceWire terminals. With respect to the standard traffic analyzers, the design of this new tool includes the possibility to internally reshape the LVDS signal. This improvement increases the robustness of the analyzer towards environmental noise effects and guarantees a deterministic delay on all analyzed signals. The analyzer core is implemented on a Xilinx FPGA, programmed to decode the bidirectional LVDS signals at Link and Network level. Successively, the core packetizes protocol characters in homogeneous sets of time ordered events. The analyzer provides time-tagging functionality for each characters set, with a precision down to the FPGA Clock, i.e. about 20nsec in the adopted HW environment. The use of a common time reference for each character stream allows synchronous performance measurements. The collected information is then routed to an external computer for quick analysis: this is done via high-speed USB2 connection. With this analyzer it is possible to verify the link performances in terms of induced delays in the transmitted signals. A case study focused on the analysis of the Time-Code synchronization in presence of a SpaceWire Router is shown in this paper as well.
© (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Scige J. Liu, Scige J. Liu, Giovanni Giusi, Giovanni Giusi, Anna M. Di Giorgio, Anna M. Di Giorgio, Nello Vertolli, Nello Vertolli, Emanuele Galli, Emanuele Galli, David Biondi, David Biondi, Maria Farina, Maria Farina, Stefano Pezzuto, Stefano Pezzuto, Luigi Spinoglio, Luigi Spinoglio, "A traffic analyzer for multiple SpaceWire links", Proc. SPIE 9152, Software and Cyberinfrastructure for Astronomy III, 91522H (25 July 2014); doi: 10.1117/12.2056620; https://doi.org/10.1117/12.2056620


CubeSat developments at Cal Poly the standard deployer and...
Proceedings of SPIE (November 06 2000)
Space qualification of a commercial GPS receiver
Proceedings of SPIE (August 09 1992)
Initial evaluation of AMSU-B in-orbit data
Proceedings of SPIE (August 18 1998)
CALIPSO: lidar and wide-field camera performance
Proceedings of SPIE (October 25 2004)

Back to Top