9.1 packetcap
The packetcap files are telemetry packet description files mimicked on the Unix
termcap files.
Full definition of packetcap files is kept in a separate paper document. In brief
however one shall note the following guidelines :
- comment lines begin with #
- a packetcap entry relative to single packet type may span more lines
- the first line shall begin with the (packet) identifier followed by a pipe (|) and
a comment, followed by field entries
- all lines but the last must be terminated by a continuation mark, i.e. a
backslash (\) not followed by any blank ! Continuation lines are
preferably aligned not in column one.
- field entries are delimited by semicolons (:)
- field names are two or three characters (this is an extension to the Unix termcap)
- There are three types of fields
- boolean fields with no values, e.g. :ve:
- integer fields with numeric values, e.g. :pl#1912:
- string fields with values, e.g. :f1=TIME:
- a particular field is :tc=identifier:, which chains the current
definition to another packetcap entry (this is useful when more packets
share a common set of definitions)
- current routines use a
basic type :bt#n: and
secondary type :st#m: field to classify similar packet layouts
together
- other fields like packet length :pl#n: and
number of items :ni#m: are relevent to an entire packet
- a packet item can be an event, or a spectrum, or an HK sample, and then contain
:nf#n: fields, each of them (i=1,n) has characteristics like
a field name :fi=name:,
a field size :si#k:, etc.
Packetcap files are stored in an instrument specific subdirectory of the
calib directory, therefore can be mantained
separately for different missions and instruments.
The current packetcap files for SAX instruments can be inspected here :
sax.iasf-milano.inaf.it/Xashelp/Prog/instr.1.html
:: original creation 2002 Sep 04 18:21:18 CEST ::
last edit 2002 Sep 04 18:21:18 CEST