Command line interface
detailed description of data recording; a summary is given in section 4.5.3 on page
29.
The flash memory is used as a ring buffer. Two pointers into the memory keep track
of where data were last read (the “Read Pointer”) and last written (the “Write
pointer”). When either pointer reaches the end of physical memory, it wraps round
back to the beginning. The behaviour when the write pointer reaches the read
pointer (i.e. when the memory becomes full of data, none of which have been
downloaded) is governed by the commands
RE-USE/RECYCLE
and
WRITE-ONCE
,
described above.
Which data are downloaded depends on the current
read pointer
, as well as various
user-configurable parameters, which allow you to select a particular stream, streams
of a specified sample rate or streams within a certain time window. You can set
parameters separately or string the definitions before the
DOWNLOAD
command. For
example,
ALL-FLASH STREAM HPA0N1 DOWNLOAD
2004 12 01 00 00 FROM-TIME ALL-DATA DOWNLOAD
100 S/S ALL-TIMES DOWNLOAD
See below for full details of the parameter-setting commands.
After each download completes, the read point is normally set to indicate the start of
the first unread block –
i.e.
where downloading would normally resume. The
exception is a download issued after an
ALL-DATA
command, which does not affect
the read point. The read point can be reset with the
ALL-FLASH
command, described
below.
The
DOWNLOAD
command, when invoked with no parameters, starts another
download with the same parameters as last time.
The
DOWNLOAD
command returns immediately, so that you can issue more
commands if required. To close the connection and begin downloading, issue the
GO
command. You can pause the download by entering terminal mode, and then either
restart it (with another
GO
) or abort it with the command
END-DOWNLOAD
.
6.12.2 ALL-FLASH
Syntax:
ALL-FLASH
Sets the read point to the oldest data held by the DM24. This command does not
alter which streams are to be transmitted; you should specify streams or use the
ALL-DATA
command in addition to this one.
6.12.3 ALL-DATA
Syntax:
ALL-DATA
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Issue U - December, 2021