demsched - scheduling for non-continuous, fixed-telemetry reception

demsched - Scheduling for non-continuous, fixed-telemetry reception

SYNOPSIS

demsched acc antenna telemetry [ [ script ] timeout ]

DESCRIPTION

demsched schedules non-continuous reception for a given fixed telemetry. Unlike tsched, demsched does not use the autosched or schedlist files. Instead, demsched operates using the following three rules:

Start rdframe immediately for a duration of 40 minutes.
If rdframe dies or does not frame any lines for twenty minutes, restart it immediately for another 40 minutes.
If rdframe starts framing lines, but does not frame any new lines for timeout seconds, restart it immediately.

Actually, demsched starts rdframe and the optional post-processing script indirectly via the capture shell script. If the optional script is to be started at the same time as rdframe, then the waitpass step in capture should be commented out or deleted.

Automatic archiving is not supported by demsched. Any archiving must be part of the optional post-processing script.

demsched uses the unknown satellite when starting rdframe. Setting the correct satellite in the online catalog is the responsibility of the optional post-processing script. For HRPT telemetry, fixpasstime can be used to set the correct satellite, start time, and duration.

demsched is normally started up at system boot time via the file $PASSDIR/tscan.rc.local.

PARAMETERS

0-relative ACC number. This should be zero for nearly all installations. ACC numbers should be listed in the file $PASSRSVP/acctelems.

0-relative antenna number. This should be zero for nearly all installations. Antennas should be listed in the file $PASSRSVP/acctelems.

Note, this parameter is required even though this type of scheduling does not really involve any antenna control.

Telemetry name, such as hrpt. Telemetry stream should be non-continuous, with some non-trivial time gap separating passes.

This optional post-processing script is started indirectly by demsched via the capture shell script. If the name of the script is none, capture does not start any post-processing. If the optional script is to be started at the same time as rdframe, then the waitpass step in capture should be commented out or deleted.

The gap in seconds signifying the end of a pass. The default is 60 seconds.

EXAMPLES

The following command starts demsched to receive HRPT telemetry, with no postprocessing and a 45 second timeout.

demsched 0 0 hrpt none 45

FILES

$PASSDIR/tscan.rc.local, $PASSRSVP/acctelems, $PASSDIR/onlinecat