independent test capability (itc) itc synchronous bus (itcsb) 1553 and spacewire interception justin...
TRANSCRIPT
Independent Test Capability (ITC)ITC Synchronous Bus (ITCSB)
1553 and SpaceWire Interception
Justin MorrisSteven SeegerBrandon BaileyScott ZemerickMark Pitts
Jeff JoltesJustin McCartyDan NawrockiGary CarvellPeter Medley
ITC Team Members
Contact Us: [email protected] Website: http://itc.ivv.nasa.gov
External Website: http://www.nasa.gov/centers/ivv/JSTAR/ITC.html
Agenda
• ITCSB Description• ITCSB Features• ITCSB Interception• Current Use– Demonstrations
• Conclusion
NASA IV&V Facility Independent Test Capability 2
ITCSB Description
• Re-usable communication mechanism– Ensures consistent and correct data passing
among distributed simulation components
• Provides synchronization between distributed applications
• Flexible and extensible design– Can be extended to incorporate any
communication protocol
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ITCSB Features
• Transport agnostic• Cross platform C++ implementation• Robust User API• Specialized Layers:– MIL-STD-1553B– ESA SpaceWire– Time Sync
• Dynamic interception allows data manipulation – Without modification to software
NASA IV&V Facility Independent Test Capability 4
ITCSB Interception
• Dynamically added and removed• Priority-based• Block, pass, and modify data– Fault injection– Bus monitoring
• Available utilities– 1553 Interceptor GUI– SpaceWire Interceptor GUI– Various command line utilities
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Development & Interception
• ITCSB used to create simulation components– Useful for easy integration into simulation environment– Common libraries guarantee communication correctness
• Interception can come later– Development can occur without any consideration of interception– Dynamic nature of interception means it can be used later without
modification to simulation component
• Interception is future-proofing– Any work can be done later without modification to code– Code can be augmented by insertion of interceptions on the
network
• Development of interceptors separate from components
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Data Flow With Interceptor
Interceptor Modifying Data
Interceptor Blocking Data
ITCSB Interception
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Node A Node BITCSB
Interceptor
Normal Data Flow
ModifyBlock
Current Use
• GPM Operational Simulator (GO-SIM)• JWST IV&V Simulation and Test (JIST)
Environment
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ITCSB is the Main Communication Hub within GO-SIM and JIST
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Conclusion
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• ITCSB provides– Communications backbone for future simulation development– Synchronization for distributed simulation components
• Mitigates timing concerns
– Interceptors that allow the changing of data without modification to software under test
• ITCSB interception is the most beneficial feature for the IV&V analysts– Provides mechanism for fault injection– Allows for testing scenarios that are often impossible with
hardware