Input to CCSDS P&P WG

Chris Taylor

CCSDS 2011 Berlin

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Introduction

• In reviewing the IEE1451 and CANOpen specs for the use of EDS, it is apparent that certain architectures are assumed by the standards

• These architectures influence the point at which interfaces are exposed and the application of the EDS

• In particular, both 1451 and CANopen assume an intelligent controller which insulate the host software from underlying details of the connected sensors and actuators

• Such an architecture is similar to that being proposed by ESA for a standard building block Remote Terminal Unit (RTU) – essentially a data concentrator

• We need to take account of these architectures both to ensure that SOIS is compatible but also to understand the use of EDS

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Cryosat

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RTU as element of P/F Avionics:

CDMU

RTURTU2015

P/F Bus

P/L Bus

MIL-STD-1553BCANRS-422SpW

ECSS-E-ST-50-13CECSS-E-ST-50-12C,…ECSS-E-ST-50-15dr

Sensors &Actuators(T, AOCS,Propulsion, …)

ECSS-E-ST-50-14CECSS for digital sensor busses

MIL-STD-1553B, CAN, SpW

MMU P/LP/LSpW, HSSL,SpF

PCU/PCDU

Power Bus

Load

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Avionics 2015: RTU2015

1. Remote terminal unit acts as a data concentrator

2. Standard interface to OBC/CDMU with a standardized protocol

3. Standard Serial bus to devices

4. S/C may employ several miniaturised versions

RTU

Standard Digital Bus (SPI, I2C, …)

Command and control Bus (Can, Milbus, SpaceWire)

Sensors and Actuators

M

HK ModuleMotor Drive

Module

MicroController

/FPGA

Standard Interface

MemoryMemory

Aeronautics/Embedded examples of RTUs

Digital Sensor bus

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RTU : possible configurations

OBC/CDMU/SMU

RTU2015 #2

Backplane

DC/DC Controller

SpWRTC

SpWRouter

RTU2015 #1

Backplane

DC/DC Controller

FPGAWith

CCIP/1553/RS422 I/F

uControllerWith CAN/

1553/RS422 I/F

HK

SLAVE

MOD

SADM

CTRL

MOD

HK

SLAVE

MOD

DigSERIAL

Bus

MOD

WIRELESS

DataCollec.

MOD.

CAN/1553B/RS422

SpW

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DeviceAccess protocol

DAS

Data linkany

DeviceAccess protocol

DAS

Data linkany

I2CSerial

1 Wire

contrFunctional

Virtual

DVS

Mem

EDS

EDS

EDS

EDS

EDS

CDMU RTU

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DeviceAccess protocol

DAS

Data linkany

DeviceAccess protocol

DAS

Data linkany

I2CSerial

1 Wire

contr

Virtual

DVS

Mem

EDS

EDS

EDS

EDS

EDS

EDS

CDMU RTU

FunctionalFunctional

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IEEE 1451 – “RTU Architecture”

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1451 – use of TEDs

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Thermal P/F

POWER S/S

PCDU

Propulsion Sub-system

ThrustersThrustersTank

Pt

ThermistorsThermistors

HeatersHeaters

1553BC

TMEncoder

TCDecoder

OBT

SMU

Platform

CPDU

P/FON/OFFHLC

PM

TC ManagementTM ManagementOBT ManagementFDIR ManagementMdM ManagementAOCS ManagementPower ManagementThermal ManagementPayload management

SecurityModule

PPS

RM Alarms

LVLV

Discrete I/Os

SADMSADM

P/F Monitoring

AOCS Sub-system

CSSCSSGPSGPS STR RWRW MAGMAG MTBMTB

P/LBC

MM

TTC RF Sub-system

S band TX

S band TX

S band RX

S band RX

Mil-1553 bus

CRSCRS

P/L C&C bus

PayloadInstruments

P/L Essential Monitoring

Payload

PayloadInstruments

PayloadInstruments

PDHT

SpaceWire

Traditional architecture

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IEEE 1451 standards

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Questions for SOIS WG

• IEEE1451 use the same architecture as the proposed ESA RTU. 1451 uses XTEDS for devices but presents a standard API for access over the user network – How does this fit with the SOIS P&P architecture, in particular the DAS and DVS

• ESA is also standardising the use of CANBus as a primary onboard bus. CANBus has its own (text based) EDS – how does this fit with the SOIS P&P architecture? (important as use of CAN will force equipment suppliers to provide EDS’s)

• There are several “object dictionaries” (1451, CAN, XTEDS) available – how (should we) do we rationalise these into a single view and document?

• Our diagrams to not yet reflect the use of a device specific protocol to support the device access service – propose this should be identified/specified as this will be needed e.g. for standard access to an RTU

• The SPA guidebook contains a section on SOIS – is everybody happy that the text correctly reflects the comparison with SPA?

• The Green book has been updated, are there still actions and updates and what are the plans for the review and release?

• Although we made a great step forwards at the last meeting and reflected the results in the Green book, I’m concerned that the GB text is a little ‘academic’ and would benefit from a practical example to supplement the layered model – comments anyone?

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Reference architecture

Onboard Communications H/W(e.g. MIL-STD-1553B, SpaceWire, CAN RS422)

System Services Application BB

MTL services

PUS library/TMTC

OBCPinterpreter Plan/ Autonomy

Framework

Mission TL/ Mode mgmt

Central FDIR

AOCS

P/L Manager

Thermal

Power

Execution framework

OBC Hardware

CAN RS422

TM/TC

Sensors(Star Trackers, Sun sensors, Gyros, Earth

sensors, magnetometers)

Actuators(Reaction wheels, magneto torquers,

thrusters, etc)

OBT Mgmt

SSMM Mgmt

EquipmentMgmtContext

Mgmt

MIL-1553 SpW

CPU/Multicore

EEPROMBoot

PROM

OB Timer

Safe GuardMemory

HWwatchdog

BSP

Middleware services

Software bus

SecurityUnit

Payloads &Instruments

SSMM

RTU Payload Control Computer

SOIS Layers

Legacy devices

Standardized devices

SOIS Layers

ADCs / DACsSOIS Layers

RAM Digital Sensorbus

Payload Data Processing

DSP

Libraries:Math, Security,

Payload,…

StorageCompression

High Speed TelemetryEncryption

SOIS Layers

SOISLayers

TC decoder

TMEncoder

SOIS Subnetwork Layer

ApplicationLayer

SOISCommunication

Services

Standardized devices

Filing System

CompressEncrypt

ECSS DatalinkProtocols

ReconfigModule

Time synch

Payload TM Link

EssentialTM

RTOS

“minitor”

Microcontroller

EssentialTM

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Thermal P/F

POWER S/S

PCDU

Propulsion Sub-system

ThrustersThrustersTank

Pt

ThermistorsThermistors

HeatersHeaters

1553BC

TMEncoder

TCDecoder

OBT

SMU

Platform

CPDU

P/FON/OFFHLC

PM

TC ManagementTM ManagementOBT ManagementFDIR ManagementMdM ManagementAOCS ManagementPower ManagementThermal ManagementPayload management

SecurityModule

PPS

RM Alarms

LVLV

Discrete I/Os

SADMSADM

P/F Monitoring

AOCS Sub-system

CSSCSSGPSGPS STR RWRW MAGMAG MTBMTB

P/LBC

MM

TTC RF Sub-system

S band TX

S band TX

S band RX

S band RX

Mil-1553 bus

CRSCRS

P/L C&C bus

PayloadInstruments

P/L Essential Monitoring

Payload

PayloadInstruments

PayloadInstruments

PDHT

SpaceWire

Traditional architecture

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Avionics 2015: Platform S/s and I/Fs

OBC/CDMU/SMU

RTURTU

P/F Bus

P/L Bus

MIL-STD-1553B(CAN)

Sensors &Actuators(T, AOCS,Propulsion, …)

TX

AOCSSensors & actuators

Propulsion

PCDU

analog

digital

AOCSSensors & actuators