GLAST LAT Project
Gamma-ray Large
Area Space
Telescope
T&C Database Management, 1 July 2005
GLAST Large Area Telescope
T&C Database Management
1 July 2005
Bryson Lee
blee@slac.stanford.edu
650-926-2866
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GLAST LAT Project
T&C Database Management, 1 July 2005
Topics
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Database Format(s)
Available Content
Missing Content
Content Producers
Tools
Content Consumers
Management Strategy
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GLAST LAT Project
T&C Database Management, 1 July 2005
Database Format(s)
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XML representation
– .catc / .cath files in CVS repository of each FSW
constituent.
– engineering-unit (EGU) conversions in LATTE schemata
Python representation
– class definitions for each command & telemetry mnemonic,
part of FSW's “VPI” package.
Oracle representation
– Set of relational tables in SLACDEV / SLACPROD Oracle
instances.
Flat-file representation
– Text files with “.dbx” file extension.
– Format (theoretically) governed by DFCD.
– LAT deliverable to GLAST project.
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GLAST LAT Project
T&C Database Management, 1 July 2005
Available Content
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Record types (with dbx monicker):
– Subsystem names for grouping mnemonics (ssi)
– Telemetry mnemonics (tlm)
– Analog polynomial EU conversions (alg)
– Discrete EU conversions (dsc)
– Arbitrary EU conversions (xpr)
• look-up table generated from a mathematical expression
– Limits on mnemonic values (lim)
– Attributes of CCSDS telemetry packets (map)
– Associations of packet contents to mnemonics (pkt)
– Command mnemonics (cmd)
– User-specified command data fields (fld)
– Discrete values for command data fields (sub)
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GLAST LAT Project
T&C Database Management, 1 July 2005
Missing Content
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Command functional verifications / responses
Telemetry mnemonic units (determined by EU conversion
algorithm)
Default telemetry “presentation” format
– How to represent the mnemonic value for display
– Something like FORTRAN formatted-io specifier (“F6.2”), or
C printf format specifier (“%6.2f”)
EU-to-raw conversions for command mnemonic data fields.
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GLAST LAT Project
T&C Database Management, 1 July 2005
Content Producers
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Flight Software
– telemetry & command mnemonic definitions
– database content intimately tied to FSW code
– records derived from XML representation
Subsystems / Systems
– Ground limits
– Command functional verifications
– LAT direct / hardware telemetry mnemonics
– Engineering unit conversions
CHS
– “Derived” records (map, ssi)
– “Value Added” tlm / cmd mnemonics
• Alternative representations to assist operations
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GLAST LAT Project
T&C Database Management, 1 July 2005
Tools
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LCAT (maintained by FSW)
– generates flat-file and Python representations from XML
representation.
– also generates C-language structure definitions for FSW
dbxodb (GOTS ITOS component)
– compiles .dbx files into a form directly usable by ITOS.
– can generate HTML documentation of .dbx content
mkdb.sh (maintainted by CHS)
– wrapper script for dbxodb that generates missing
map/pkt/tlm/ssi records and merges ISOC “value-added”
content with FSW-supplied content
useDbx.py (maintained by CHS)
– generates SQL statements to insert .dbx content into Oracle
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GLAST LAT Project
T&C Database Management, 1 July 2005
Content Consumers
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FSW
– C structures from LCAT compiled into FSW constituents
FSW Test
– Python representation from LCAT used by LTX script
engine
I&T Online
– Python representation from LCAT used by LATTE5
CHS
– flat-file representation used to “stoke” Oracle
representation and configure local ITOS installations
– Oracle representation used for CHS monitoring, Mission
Planning, Timeline Reconciliation, etc.
MOC
– flat-file representation used to configure ITOS for all LAT
operations
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GLAST LAT Project
T&C Database Management, 1 July 2005
Strategy
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CHS team is focal point for integrating database content and
delivering updates.
Need to evolve tools and processes for:
– Entering redlines to contents
– Generating and tracking database releases
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