ECSSEST5015 C Adoption Notice Maurizio Caramia This document

ECSS-E-ST-5015 C Adoption Notice Maurizio Caramia This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 1 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

The EXOMARS Mission The Exo. Mars mission is split into two steps: • The 2016 mission launched on 14 th March 2016 consisting of a Trace Gas Orbiter (TGO) and an EDL Demonstrator Module (EDM) • The RSP mission (planned in 2020) consists of a Rover accommodated inside a Descent Module (DM) carried to Mars by a Carrier Module (CM) EXM 2016 Mission EXM RSP Mission This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 2 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space CAN + CANOPEN THALES ALENIA SPACE INTERNAL

EXOMARS Physical Layer The Selected physical layer is the RS 485 (DS 16 F 95 transceiver) with daisy chain topology according one of the two options proposed by the CAN ECSS The fail safe network is implemented within the master node The daisy chain connection is realized at harness connector level This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 3 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

EXOMARS CAN Transfer Layer • Taking into account that OBC SW cycle has a period of 100 ms during which TMs have to be acquired/elaborated and CMDs have to be generated, TM/CMD exchange will be regulated according to periodic timing windows delimited by two SYNC messages and divided into two phases: one dedicated to TMs reception (70 ms) and one dedicated to CMDs generation (30). The period of each window will be 100 ms. • After a node power-on, reset node, reset application or bus switch slaves nodes shall consider the first SYNC message received after an NMT command “Go to OPERATIONAL” as the start of the first TM/CMD window. OBC SW cycle, i Ref. = TPDO TM k TPDO TM 2 TPDO TM 1 SYNC t=100 ms This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 4 CMD 2 CMD 1 TPDO TM m t=30 ms (TBC) SDO TM TPDO TM 2 TPDO TM 1 NMT “Go to Operational” t TPDO TM n t=70 ms (TBC) SYNC TM sub-window CMD n TM sub-window ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL OBC SW cycle, i+1

CABCOM From Scientific to Telecom applications Starting from the EXOMARS experience, TAS executed the ESA CABCOM study with the following main goals: To implement a fully ECSS-E-ST-50 -15 C compliant CAN bus solution for SATCOM To validate the implemented CAN solution in a dedicated test bench with HW in the loop To upgrade the CCIPC to include: A-cyclic Synchronous PDO capability Reception of Broadcast PDO for time distribution Upgrade the CCIPC reconfiguration algorithm to support the infinite bus toggling. This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 5 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

CABCOM Physical Layer Four subnetworks composed of 31 node each operated in time multiplexing by a single master Subnetwork 4 Node 92 Master Node Two different physical layers have been considered according the CABCOM study requirements: RS-485 network M Node 96 Node n Node 121 R Subnetwork 3 Node 62 M Node 65 Node n Node 91 R Subnetwork 2 Node 32 M Node 34 Node n Node 61 R M Subnetwork 1 Node 2 Node 3 Node n Node 31 ISO-11898 network A single network with 120 nodes operated in time multiplexing by a single master Master Node R M Node 2 This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 6 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL Node 3 Node n Node 121 R

CABCOM CAN Transfer Layer Each TS is organized in different windows in which different message transaction will be applied: Synchronous Window (SW): in this window only Synchronous PDO transactions are allowed The window starts with the SYNC message generated by the Master and last 1 second After the SYNC message, all the S-TPDO generated by the NODEs belonging to the specific TS will be received by the Master The synchronous windows Length parameter of each Slave node will be set to avoid S-TPO transmission outside the SW Asynchronous Window (AW): In this window only the Asynchronous On-request transactions are allowed. The Master will send the TM_RQST command to all slaves belonging to this window The Slave will reply with the requested parameter A complete transaction (Master Request and Slave Reply) will be completed before the start of a new transaction. Only requests to the nodes belonging to the specific TS will issued by the Master The AW will last 6 seconds Configuration Window (AW): In this window only the Configuration (non-acknowledged) commands will be issued by the Master After the Configuration Commands the Master Shall issue its Hearth. Beat Message The AW will last 1 seconds This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 7 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

ECSS-E-ST-50 -15 C requirement analysis 226 requirements This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 8 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

ECSS-E-ST-50 -15 C requirement analysis 21 deleted 226 requirements 12 modified 19 to be tailored 173 accepted 1 new This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 9 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

ECSS-E-ST-50 -15 C requirement analysis 21 deleted 226 requirements 12 modified 19 to be tailored 173 accepted 1 new Deleted requirements are all related to the RS 485 physical layer Modified requirements: typo corrected, all references to RS 485 have been removed, references to external standards have been removed as much as possible To be tailored are mission dependent: need for isolated transceiver; bus topology requirements; need for SDO service; need for SCET; bus redundancy architecture New: one requirement dedicated to the Sampling point settings have been added This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 10 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

ECSS-E-ST-50 -15 C requirement analysis 21 deleted 226 requirements 12 modified 19 to be tailored 173 accepted 51 SS and EQT 205 requirements 44 SS 110 EQT 1 new Deleted requirements are all related to the RS 485 physical layer Modified requirements: typo corrected, all references to RS 485 have been removed, references to external standards have been removed as much as possible To be tailored are mission dependent: need for isolated transceiver; bus topology requirements; need for SDO service; need for SCET; bus redundancy architecture New: one requirement dedicated to the Sampling point settings have been added This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 11 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

ECSS-E-ST-50 -15 C requirement analysis 21 deleted 226 requirements 12 modified 19 to be tailored 173 accepted 51 SS and EQT 205 requirements 44 SS 110 EQT 1 new Mandatory: Requirements applicable to both Full and Minimal Protocol implementation covering: 49 Full Protocol 112 Mandatory 205 requirements 34 Minimal Protocol • Physical layer requirements • CAN data link layer requirements • CANOpen mandatory services (OD, NMT, PDO) Full Protocol: contain the full set of CANOpen services (EXOMARS heritage) Minimal Protocol: contains a subset of CANOpen services (no SDO) to support SATCOM payload busses (NEOSAT heritage) This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 12 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

ECSS-E-ST-50 -15 C requirement analysis 21 deleted 226 requirements 12 modified 19 to be tailored 173 accepted 51 SS and EQT 205 requirements 44 SS 110 EQT 1 new 44 SS only 78 Mandatory 171 Full Protocol 49 Full Protocol 34 Slave 112 Mandatory 205 requirements 15 Master 34 Minimal 41 SS only 156 Minimal 66 Mandatory 11 Master 38 Slave This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 13 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

Conclusions RS 485 physical layer has several drawbacks: • Limited number of nodes • It requires a failsafe network • The fail safe network is usually implemented within the On-Board computer electronics : • It shall be powered in hot redundancy • Special care shall be taken to its distribution to main and redundant OBC boards. Usually the main board accommodate only the main CAN bus fail safe network while the redundant board accommodate the redundant one. • Only 5 volts transceiver are available Sampling point configuration shall be reprogrammable • The sampling point is function of the bus length. The worst case bus length could be reached during the On-ground testing activities if a bus repeater is not introduced between the test equipment and the Spacecraft. Special care shall be taken to the Endianness management. • Dedicated guidelines should be added in the ECSS As matter of fact, the protocol above the CANOpen layer is mission dependent. It shall be covered by a dedicated specification explaining how the CANOpen services are used (NOTE: the ECSS only specified which CANOpen services can be used and How they shall be implemented) This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 14 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL

Thank you! Questions This document is not to be reproduced, modified, adapted, published, translated in any material form in whole or in part nor disclosed to any third party without the prior written permission of Thales Alenia Space. 15 Ref. = ESA CAN Work. Sohp 2017 Template Ref. = 83230347 -DOC-TAS-EN-004 © 2017 Thales Alenia Space THALES ALENIA SPACE INTERNAL