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Example of EDS usage in SOIS [recap from SAFI meeting 23/6/2012]

Example of EDS usage in SOIS [recap from SAFI meeting 23/6/2012]. F. Torelli CCSDS SOIS WG, Darmstadt 17/04/2012. Introduction. Objective: To give an example of how SOIS C&DA services and EDS can map to Star Tracker TM/TC ICD. Inputs: STR_TM_TC_packets_V4.xls

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Example of EDS usage in SOIS [recap from SAFI meeting 23/6/2012]

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  1. Example of EDS usage in SOIS[recap from SAFI meeting 23/6/2012] F. TorelliCCSDS SOIS WG, Darmstadt17/04/2012 ESA UNCLASSIFIED – For Official Use

  2. Introduction • Objective: • To give an example of how SOIS C&DA services and EDS can map to Star Tracker TM/TC ICD. • Inputs: • STR_TM_TC_packets_V4.xls • Report from CCSDS SOIS Spring Meeting 2011 • Notes from CCSDS SOIS Fall Meeting 2010 • Entities involved: • Dictionary of Terms (DoT) • Electronic Data Sheet (EDS) • Device Access Service (DAS) • Device Virtualisation Service (DVS) ESA UNCLASSIFIED – For Official Use

  3. SOIS PnP Architecture Standardised interface including semantics. Ref. sheet 1 in STR_TM_TC_packets_V4. Applications Contains the ICD of the devices w.r.t. the SOIS service interfaces. Device Virtualisation Service Device specific functional interface. Ref. sheet 2, 3, 4 in STR_TM_TC_packets_V4. Device Enumeration Service DoT EDS Device Access Service SOIS Contains syntactic and semantic types. Subnetwork Device Discovery Service Subnetwork Packet or Memory Access Service Subnetwork Management and Configuration Subnetwork Plug-and-Play Protocol Subnetwork Protocol Implementations Policy Subnetwork Implementation Hardware ESA UNCLASSIFIED – For Official Use

  4. Dictionary of Terms & Electronic Data Sheet • The DoT contains the attributes to be used to describe the device and in particular its interfaces (i.e. syntactic and semantic types). • The DoT is the vocabulary used to build the EDS for a particular device. • The elements of the DoT arranged (and instantiated) in the EDS for a specific device allow to associate a meaning to the raw data in the “TM and TC” of that device. • The EDS describes the mapping between the layers in the SOIS Command & Data Acquisition (C&DA) in terms of service primitives and their parameters. • The EDS describes the mechanisms to send/receive data to/from the devices and how to elaborate them along the C&DA stack. ESA UNCLASSIFIED – For Official Use

  5. Example of DoT (1/2) The provided types are examples used along the presentation for practical reasons, but are not the finalised elements of the SOIS DoT. Basic Syntactic Types: Composite Syntactic Types: ESA UNCLASSIFIED – For Official Use

  6. Example of DoT (2/2) The provided types are examples used along the presentation for practical reasons, but are not the finalised elements of the SOIS DoT. Semantic Types: ESA UNCLASSIFIED – For Official Use

  7. Example of EDS for DAS Global subnetwork address is function of the subnetwork type (i.e. Mil1553), STR address within the subnetwork (i.e. RT 03), but also of the subnetwork management policy. Subset of EDS for SODERN HYDRA (DAS  Subnetwork) ESA UNCLASSIFIED – For Official Use

  8. Example of DAS implementation using EDS information To acquire the value Quat of QRsFil (filtered fused attitude quaternion), the Device Access Service user shall invoke the following service primitives: Acquire_From_Device.request(DASAP, TransId, STR-A,QRsFil); … Acquire_From_Device.indication(DASAP, TransId, Quat, ErrorCode); DAS service primitives can then be implemented by means of Packet Service primitives calls, for example as follows: Acquire_From_Device.indication(DASAP, TransId, Val, ResultMeta) { Packet_Receive.indication(PSSAP, Mil-RT03, BE, SAInfo, PktData); for (I = 0;I < Pkt Field Size; I++) Val[I] = PktData[I + Byte Pos]; } In red, relevant output parameters In blue, elements of the EDS ESA UNCLASSIFIED – For Official Use

  9. Example of EDS for DVS Subset of EDS for SODERN HYDRA (DVS  DAS) ESA UNCLASSIFIED – For Official Use

  10. Example of DVS implementation using EDS To command the update of the linear velocity (VabXc, VabYc, VabZc) to value Vel, the Device Virtualisation Service user shall invoke the following service primitives: Command_Device(STR-Nom,Linear Velocity, Vel, ErrorCode); DVS service primitives can then be implemented by means of DAS primitives calls, for example as follows: Command_Device(Device Id, Attribute Id, Value, ResultMeta) { if (Device Id == STR-Nom) Dev = STR-A; else Dev = STR-B; if (Attribute Id == Linear Velocity) { VelX = Double-To-Int(Value[0]); VelY = Double-To-Int (Value[1]); VelZ = Double-To-Int (Value[2]); Command_Device.request(DASAP, TransId0, Dev, VabXc, VelX); Command_Device.request(DASAP, TransId1, Dev, VabYc, VelY); Command_Device.request(DASAP, TransId2, Dev, VabZc, VelZ); } } More elaborated conversion law can be applied here In green, relevant input parameters In blue, elements of the EDS ESA UNCLASSIFIED – For Official Use

  11. SOIS PnP Architecture - Recap EDS contains different sections covering the different SOIS service/abstraction layers. Its content is mainly filled in by equipment manufacturer. Applications Device specific functional interface, uses the existing equipment capabilities and fits in the SAVOIR-FAIRE SW architecture. Device Virtualisation Service Device Enumeration Service DoT EDS Device Access Service SOIS Types to be defined with the main contribution of SAVOIR-SAFI WG. Framework, specifications of formats and mechanisms need to be defined by SOIS WG to enable definition and usage of DoT, EDS and C&DA services. Subnetwork Device Discovery Service Subnetwork Packet or Memory Access Service Subnetwork Management and Configuration Subnetwork Plug-and-Play Protocol Subnetwork Protocol Implementations Policy Subnetwork Implementation Hardware ESA UNCLASSIFIED – For Official Use

  12. Summary • Examples of DoT and EDS using elements of the provided Star Tracker TM/TC ICD have been presented as well as a possible service implementation. • EDS, DVS and DAS allow flexibility in the usage and implementation, still preserving standard service interfaces. • DAS interface (device specific functional interface) and the related sections of the EDS can be defined and used with the existing equipment without modifications. • The mechanisms to access DoT and EDS and their formats are under definition by the SOIS WG. • The implementation of DAS and DVS can easily follow a recurrent design pattern, which would in the future also enable auto-coding of part of the services and user applications. • SAVOIR-SAFI in the short term would be very helpful in contributing to the definition of the Common Data Dictionary content (semantic and syntactic types) in order to represent the interfaces of the existing equipments. ESA UNCLASSIFIED – For Official Use

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