1. Real-Time Systems Presented by: www.scisys.co.uk Stuart D Fowell SciSys AMS Prototyping CCSDS Spring 2008 Meeting, Washington D.C, USA

2. SciSys AMS Prototyping - CCSDS Spring 2008 11th March 2008 2 Overview  Project Overview & Reference Mission  Constraints & Assumptions  Use Cases  Tailoring of Specification & Feedback  Design & Implementation

3. SciSys AMS Prototyping - CCSDS Spring 2008 11th March 2008 3 SOIS Reference Implementation  SciSys (UK) and Astrium SAS (FR)  Customer: ESA  Jan – Oct 2008  Objectives:  Prototype SOIS architecture over SpaceWire and MIL-STD- 1553B  Inc. implement tailored AMS in SOIS, driven by onboard use cases  Investigate SOIS Plug-and-Play architecture on SpaceWire  Deploy on ESA’s RASTA Test Facility for future use  Provide feedback on SOIS Red Books  Provide draft Device Enumeration and Virtualisation Red Books

4. SciSys AMS Prototyping - CCSDS Spring 2008 11th March 2008 4 Reference Mission

5. SciSys AMS Prototyping - CCSDS Spring 2008 11th March 2008 5 Constraints & Assumptions  Only focussed on onboard software architecture  Hence, no RAMS Gateway  Use SOIS Subnetwork Packet Service as AMS transport layer & offer available QoS’s to users  Allow for integration into wider system FDIR strategy of active/redundant system nodes  Simplifies Configuration Manager and Registrars  But not a focus for this project  Modular design so only required functions are linked in

6. SciSys AMS Prototyping - CCSDS Spring 2008 11th March 2008 6 Use Cases  Send Message from Onboard Application to Onboard Application  E.g. a Mission Timeline application sends a telecommand to a Payload Controller  Query from Onboard Application to Onboard Application  E.g. an FDIR application queries the status of a Payload Controller application  Announce from Onboard Application to other Onboard Applications  E.g. an FDIR application notifies a group of Payload Controller applications to shutdown  Publish Message from Onboard Application to Subscribed Onboard Applications  E.g. a Payload Controller application publishes the latest data to interested applications, e.g. a Mission Autonomy Controller application

7. SciSys AMS Prototyping - CCSDS Spring 2008 11th March 2008 7 Tailoring of Specification & Feedback  See SciSys TNs:  DOC 006 AMS Terminology Understanding v1.0a  DOC 007 AMS Draft Standard Feedback v1.0a  DOC 008 AMS Implementation Assumptions v1.0a

8. SciSys AMS Prototyping - CCSDS Spring 2008 11th March 2008 8 Design & Implementation  Modular Design using UML 2  Implemented using MISRA subset of ANSI C  RTEMS operating system  LEON2 SPARC-based processor  SpaceWire Network and MIL-STD-1553B bus  Best Effort, Assured and Reserved SOIS QoS  Prototype on Linux PC with UDP simulation of SpaceWire  Port to ESA’s RASTA Test Facility