1. Use of EDS for S/W Bus Adaptor CCSDS SOIS 2013 Spring Meeting Jonathan Wilmot NASA GSFC

2. Exemplar CFS Architecture
Spacecraft
Data
Recorder
Checksum
Limit
Checker
CFDP File Transfer
File
Manager
Stored
Commanding
Data
Storage
Instrument 1
Manager
Instrument 2
Manager
Scheduler
Recorder
Manager
GNC Sensors
Onboard
Models
5 Hz
GPS
232
GPS IO
House keeping
Software
Bus
Time
Services
Table
Services
Executive
Event
Health
&
Safety
Control
Law
Altimeter
232
5 Hz
Services
Services
Alt IO
422
50 Hz
State
Determination
IMU
LN200 IO
Inter-task Message Router (SW Bus)
Cnd
Ingest
EDAC
Memory
Scrubber
Time
Manager
Space
Wire
Power
Housekeeping
Recorder
1553 Bus
Controller
Telemetry
Output
C&DH App
GN&C App
S/C
Data
CFS App
RAM & EEPROM
SBC
1553
Time HW
SpaceWire
Power hw
S-Comm
cFE App

3. CFS Software Bus (SB)
CFS components publish/subscribe to CCSDS packets
Packets are either telecommand or telemetry
Publishers have no knowledge of subscribers
One publisher to many subscribers is typical
Control log, Fault management, data storage, telemetry output
Send and forget
Subscribers can request packet meta data (Publisher appid, system, subsystem)
Subscriptions are based on packet app id (2^11)
Common CFS applications use a consistent set of app ids, but missions can redefine them
C structures are used in the software to extract packet data
CCSDS headers are not part of the C structures but via abstractions
Ad-hoc tools are used to convert between C structures and ground systems and tool databases
Common definition parsed to generate packet definitions for other systems
NASA working to establish CFS governance model and community
Architecture, software, and tools commonality across many NASA missions
Potential support for SOIS MTS compliance (Likely in the long term)

4. CFS Software Bus (SB) SB implements QOS only at the network interfaces
SB API accepts QOS parameters and passes them down
There is a Software Bus Network (SBN) component that plugs in for each network type (Ethernet, TTEthernet,1553, SpaceWire...)
SBN is also used for interpartition (ARINC 653, PikeOS...), inter-core messaging (Multi-core), and intra-processor
SB is not aware that SBN(s) exists
SBN will pass network to network through traffic
SBN implements a peer to peer network
No protocol master, connection mappings are kept local
Peers can come and go at runtime
All subscription requests are replicated (This can have scaling issues)
Ground interfaces are through Command Ingest and Telemetry Output plugins
Not all components look at packet contents
Data storage, telemetry output, both just filter and forward

5. Formats
CFS may move toward the DEM format which moves beyond the 2^11 appid (topic) limitation
Support for audio and video encapsulation
CCSDS format
Data Exchange message (DEM) format

6. EDS gets used in many places
EDS(s)
Subnetwork services
Channelizations and
service type (packet…)
defined here
Data
Consumers
I/O
Schedule
Device
SpaceWire
I/O
Device
Device specific driver(s)
Device
I/O
Schedule
device
Raw Sensor processing
device
RIU
Partition, core, network…
device
1553
I/O
Device
Device
Device
I/O
& Driver
Software Bus Network
(SBN)
Software Bus Network
(SBN)
422
Device

7. Use of EDS in the System Stack
Layered Approach:
Use of EDS in the System Stack
HW and/or software
logic
SpaceWire
1553
Subnetwork
I/O
Sensor
Processing
Telemetry
Output
EDSes are incorporated into other EDSes up the stack. All of the spacecraft EDS eventually provide input into the ground systems and operational databases.

8. Meta data for file contents?
End to End
EDS
EDS
XTCE
database
EDS
comm
Telemetry
monitors
Control Center
EDS
Software Bus SOIS MTS
EDS
Star Tracker
EDS
Reaction
Wheel
EDS
RTU driver
EDS
EDS
File
Manager
EDS
Command
EDS
Telemetry
comm
CFDP File
Transfer
EDS
EDS
EDS
SOIS
Stack HW
RTU
Mass
Storage
Meta data for file contents?
XTEDS HW
thermistor
thermistor
EDS
1451 HW
1451