Exchanging Databases with Dissimilar Systems Using CCSDS XTCE

1
Exchanging Databases with Dissimilar Systems
Using CCSDS XTCE

• CCSDS Spacecraft Monitoring Control WG
• And
• OMG Space Domain Task Force
• Presented by Mario Merri, ESA

2
Outline

• Where does XTCE come from?
• Its goals and benefits
• How does it work?
• Usage so far
• Conclusions

3
XTCE History

• Object Management Group (OMG) standard originally
  developed by
• European Space Agency
• US Air force/Mission Operations (Lockheed Martin)
• Boeing Communications Satellites
• NASA JPL
• Being adopted by CCSDS via Agency Review under
  responsibility of SMC WG

4
CCSDS SMC and XTCE

• ESA
• M Merri (chairman),
• M Schmidt, A Ercolani,
• J Muller, I Dankiewicz,
• S Cooper
• BNSC
• R Thompson (deputy chairman), B Harnett
• CNES
• B Béhal, E Poupart,
• R Soumagne
• CSA
• P Melanson
• DLR
• H Hofmann
• INPE
• PG Milani, AM Ambrosio

• JAXA
• T Yamada
• NASA/GSFC
• DC Lokerson, F Johnson,
• JK Marquart, JS Gal-Edd,
• C Fatig, R Jones , K Rice
• NASA/JPL
• A Oyake, P Shames, J Moholt
• ASI
• C Labonia
• OMG
• G Simon (Lockheed Martin),
• B Kizzort (Harris Corp.)

XTCE Splinter Group
5
XTCE Goal

• XML-based non-proprietary standard format for
  exchanging TM/TC databases that will reduce
• human errors,
• ambiguities, confusion, and
• lost time in difficult, sometimes lousy (painful)
  conversions between dissimilar systems

6
Application field

• Exchange between
• working teams
• missions
• systems
• agencies
• Reuse database
• Reduce costs

Planning Scheduling
XTCE Format
Command Management
Instrument Manufacturers
Real time
Spacecraft Manufacturers
Simulators
Trending
Analysis
7
XTCE Benefits

• Better interoperation between space agencies and
  contractors (or any other actor)
• Lets different philosophies collaborate in one
  data model
• Separates pure telemetry and telecommand data
  from dedicated/proprietary processing data
• Extensible for data items not currently defined

8
XTCE in a nutshell (1/8)

• An XML Schema language describing data for
• Telemetry definitions
• Data transmission and packaging
• TM/TC parameter properties
• Telecommand definitions
• Non TMTC data is not considered part of XTCE
  (dedicated software instructions, SW
  configuration variables, page definitions,
  real-time scripts, etc.)
• TM and TC definitions are 80 similar between
  space systems

9
XTCE in a nutshell (2/8)

• XTCE describes a SpaceSystem - command
  telemetry descriptions, in a hierarchical format
• The granularity of a space systems description
  is left to the user, e.g. SpaceSystem may
  contain SpaceSystem(s)
• The hierarchy allows integration of multiple
  databases into one overall database
• ex multi-satellite missions, multi-instrument
  satellite

10
XTCE in a nutshell (2/8)
Space System
Spacecraft level
Space System
Space System
One satellite DB
Instrument level
Space System
Space System
Device level
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XTCE in a nutshell (2/8)
Space System
Constellation level
Space System
Space System
Multi-satellite DB
Satellite level
Space System
Space System
Instrument level
12
XTCE in a nutshell (3/8)

• A space system in XTCE is able to describe
• Telemetry parameters, their packaging and
  dedicated processing
• Telecommand parameters, commands, its packaging
  and dedicated processing
• Streams (up and down, with coding information)
• Maintain minimal configuration information
• Conversion information
• Limits and pre/post command checks

13
XTCE in a nutshell (4/8)
Space System

• Header for configuration data
• Default for generic settings
• Telemetry for core data
• Telecommand for core data
• Services for frames identification

Header
Defaults
Telemetry
Telecommand
Services
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XTCE in a nutshell (5/8)

• Telemetry data is distributed in several
  elements
• Parameter types
• Parameters (instances of parameter types)
• Containers (aka packets)
• Messages
• Streams
• Algorithms

15
XTCE in a nutshell (6/8)

• Logical sequence of definitions
• Parameter types (alarms, calibrations)
• Parameter instances
• Containers (Packets)
• Streams, messages and algorithms
• Example CCSDS TM frames, packets and XTCE
  containers

16
XTCE in a nutshell (7/8)

• Parameters are put in sequence to form packets
  (containers)
• Packets are put together to form frames
• Streams are defined on top of generic frames

Frame primary header
Frame secondary header
Frame data field
Op.ctrl
Err.ctrl
Frame
Packet
Packet header
Packet data field
Ver
Type
P.hdr f
APID
Gr. f
SSC
P.h.len
Packet header
17
XTCE in a nutshell (8/8)

• Telecommand data is distributed in several
  elements
• Parameter types
• Parameters
• Containers
• Messages
• Streams
• Algorithms

18
XTCE Applications so far

• James Webb Space Telescope XML Schema have been
  converted
• Future work includes exchanging database with
  other archive systems and control center
  real-time systems
• SCOS-2000 ASCII files have been converted
• Hardware vendors deliver the database information
  in XTCE format to the spacecraft integrator on
  some US programs

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CCSDS Documentation

• Draft CCSDS Green book release along with XTCE1.1
  for internal CCSDS review
• CCSDS Magenta book (detailed user guide) is being
  written
• CCSDS Red Book released

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Conclusions

• XML self-describing nature reduces learning curve
  and errors
• XML is easy to work with, due to the amount of
  libraries, tools, and broad industry acceptance
• XTCE powerful concepts are ideal for exchanging
  legacy, current and future TM TC databases to
  planning systems, engineering analysis tools, and
  real-time command and control systems
• Easily translated between the project XML
  database format and XTCE, no longer just a
  concept but being used internationally
• XTCE covers about 80 of the TM/TC definitions
  reducing the errors between dissimilar systems

21
Questions and Answers
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