!General

    The program EMON is designed to read the
    Engineering A and B packets in the science
    telemetry stream and to interpret the data therein. 
    Plotting of the variables within the program is
    catered for and it is also possible to pass the
    parameters read back to the IDL environment where
    they can be further displayed or stored.  If the
    program is called thus:

    IDL> emon, t,d,n

    then on exit the parameter 't' will contain an
    array of times (suitable for using in other CDS/IDL
    time routines), the variable 'd' will have
    dimensions (n,m) where n was the number of
    parameters selected within the program and m is the
    number of data points collected and the variable n
    will contain the database names of the selected
    parameters (just in case you forgot). 

    A simple IDL> save,t,d,n,file='fred'  will then
    save these data for future processing.

    It is also possible to run EMON in non-interactive
    mode. See CDS software note #26
    ($CDS_INFO_NOTE/cds_swnote_26.ps) for details

    It is also then possible to package up EMON when
    used in non-interactive mode to extract common sets
    of parameters. As an example, see the routine
    EMON_MAIN_HTRS.


!Exit

    The exit button will cause the program to exit and
    all the plots to be deleted.  Note that parameters
    can be passed to the IDL environment if EMON is
    called with those parameters.

!Hard copy ON/OFF

    Use this button to toggle the hardcopy option.  If
    hardcopy is ON, a hardcopy of every plot made on
    the screen will be made and submitted to the
    default  printer.

!Plot parameters

    Use this button to select (from the parameters
    already selected in the telemetry reading) those
    parameters to be plotted.  Multiple selections are
    allowed, a new window will be created for each
    plot.  



!Read telemetry

    When pressed this button starts the telemetry
    reading process.  At the moment this appears very
    slow (probably caused by the process of loading the
    data structures).  The reading of telemetry can be
    stopped by using the 'STOP' button.  An i/o error
    will also cause the ingestion to stop and a message
    will be flashed to the screen.


!Select A or B

    Use these buttons to switch between collecting data
    from the engineering A or B packets (they are
    mutually exclusive).

!Select parameters

    When this button is pressed, a list of all possible
    parameters (for the A/B packet selected) is
    presented.  Use the cursor to select any parameters
    you want collected from the telemetry.  The 'reset'
    button will reset the selection. The items selected
    are displayed in the main message window.



!Select telemetry files

    This button will create a standard file-selection
    widget (same as is used in the STM program).  The
    central store of telemetry data can be accessed by
    selecting 'Central Data' when this widget appears. 
    If you want to access  another directory, then
    click the 'edit path' button first and type in a
    new path.  Multiple files may be selected.  Those
    selected are displayed in a text window.

    Note that it is possible to pick up the the
    "realtime" telemetry (if it's in operation) by
    simply selecting  the latest telemetry file.  To
    see which file could be  being used for realtime
    telemetry use 

    IDL> print,gt_rt_file()

    before entering EMON.



!STOP

    Use this to interrupt the reading of telemetry.