Impact of SpaceWire networks on payload implementation and operation

1
Impact of SpaceWire networks on payload
implementation and operation
Alberto Donadoni Vitrociset c/o
ESA/ESTEC TOS-EDP
Luca Tunesi ESA/ESTEC TOS-EDP
2
Payload Processing Subsystem
High Speed Network SpaceWire
Low/Med. Speed BusCAN

High Capacity Memory
Data Compression
SpaceWire
RTI
Telemetry Formatter/ Encryption
RTI
RTI
DSP Processor
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SpaceWire ECSS-E-50-12A standard Links,
Nodes and Routers

• Links, nodes and routers possible
  implementations

• Links, Nodes and Routers
• From Physical Layer up to Character Layer
• Network Layer partially covered

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SpaceWire networks

• Two or more SpaceWire nodes
• Zero or more SpaceWire routing switches
• Interconnected with SpaceWire links
• Add bandwidth where required
• Add redundant links where required

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Path Addressing

• destination is specified as router output port
  number
• node 1 to node 3 lt3gtltcargogtltEOPgt
• node 1 to node 8 lt4gtlt3gtlt2gtltcargogtltEOPgt

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Logical Addressing

• each destination has a unique logical address
• each router has a list of which port(s) to send
  data out for each possible destination
• node 1 to node with logical address 43
  lt43gtltcargogtltEOPgt
• node 1 to node with logical address 163
  lt163gtltcargogtltEOPgt

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Router R4
3
2
1
4
4
4
Router R1
Router R2
Router R3
3
2
1
3
2
1
3
2
1
N1
N2
N3
N4
N5
N6
N7
N8
N9
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SpaceWire TopNet Technology for On-Board
Processing Networks with Extended Throughput

• Network implementation
• Network validation
• Remote integration

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Network implementation

• Remote Terminal Interface
• SnP SpaceWire Networking Protocols
• Network functionalities
• Transport functionalities

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Network validation

• Conformance analysis
• Point to Point analysis
• Protocol Analysis

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SpaceWire Conformance Tester

• Tests the conformance of interfaces to the
  SpaceWire standard
• Testing level is dependant from the degree of
  cooperation of the interface under examination
• State Machine operation
• Normal Operation
• Error Conditions

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SpaceWire Link Monitor

• Monitoring link status
• Operating modes
• stand-alone
• connected to a Logic State Analyser /
  Oscilloscope

12
SpaceWire Protocol Analyser

• Packets and Timecodes statistics
• Cargo Analysis

13
Remote Integration
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SpaceWire IP Tunnel

• PC based implementation
• Transmission of SpaceWire packets and timecodes
  through IP based networks ( internet / intranet )

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SpaceWire, TopNet and Space Operations

• Fault Detection Isolation and Recovery Exchange
  Level Errors

• Disconnect error
• Parity error
• Escape sequence error
• Character sequence error
• Credit error

• Detect error
• Disconnect link
• Report error to Network Level
• Attempt to reconnect link

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SpaceWire, TopNet and Space Operations

• Fault Detection Isolation and Recovery Network
  Level Errors

• Report error to Network Level
• Terminate current packet with EEP
• Spill current packet until EOP/EEP
• If error occurs in source or destination node,
  flag error to application layer
• If error occurs in switch node, flag error to
  external pins or internal register

• Link error
• EEP received
• Invalid destination address

• If error occurs in switch node, flag error to
  application layer

• Discard the packet

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Fault Detection Isolation and Recovery node
failure and Network Reconfiguration
MEMORY 1
R
R
P 1
P 2
SENSOR 1
R
SENSOR 2
R
P 3
P 4
R
R
Processor Array
MEMORY 2
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Fault Detection Isolation and Recovery link
failure and Network Reconfiguration
MEMORY 1
R
R
P 1
P 2
SENSOR 1
R
SENSOR 2
R
P 3
P 4
R
R
Processor Array
MEMORY 2
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SpaceWire, TopNet and Space Operations

• Implementation, validation and integration of
  payloads
• Network Integrity (Fault Detection, Isolation and
  Recovery)
• Dynamic network reconfiguration during operations
  (Logical addressing also in case of node failure)

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The ECSS-E-50-12A SpaceWire standard can be
downloaded at www.ecss.nlQuestions?
Alberto Donadoni Vitrociset c/o
ESA TOS-EDP Tel. [phone] E-mail
alberto.donadoni_at_esa.int