Commanding the instrument

Once the instrument has been powered up and is in normal operations mode, it is ready to receive commands from ground or from other processes on the satellite.

Rather than write a high-level commanding script for WXM commands, I chose to implement a single tiny program called tickle which sends a single message to a specified destination satellite process. This ends up being more powerful because the history substitution mechanisms in bash and tcsh are more powerful than a quickly hacked together commander program. It is also quite useful for insertion in scripts.

The usage of tickle is:

tickle process [type [data0 [data1 ...]]]

For now I will just give a couple of very important tickle messages for debugging and for running the science baseline test. See the `tickle_types' for more detail.

• To change the periods of the various data products, use

  tickle 2048 8224 th pha img xxx hk
  

  where th is the period for time history histograms, pha is the period for the PHA histograms, img is the period for the position (imaging) histograms, xxx is unused, hk is the period for the housekeeping data. The units are always 4ms*(number+1), for obscure reasons involving DSP assembly language code. Typical settings for flight are

  tickle 2048 8224 4 19 19 1000 249
  

  Typical settings for testing are

  tickle 2048 8224 4 399 399 1000 249
  

  because the time history telemetry gets integrated, but I'm not sure about the others.
• To tell the DSP that we are operating and it should collect HK data, use

  tickle 2048 8215
  

  Conversely, to stop collecting HK data, and to stop acting as if the instrument is on, use:

  tickle 2048 8216
  

• To collect RAW DATA words, instead of the scientific data products, use

  tickle 2048 8217 1
  

  And conversely, to turn off raw data collection and start collecting scientific data products again, use

  tickle 2048 8217 0
  

  There is another output style where we send a stream of photon tags to ground. This can be activated with (see section Extracting photon tags):

  tickle 2048 8217 2
  

• To request a dump of the current photon tag data buffer (since I have turned off the automatic sending of the tag data upon trigger until we figure out the C/Executive problems I'm having), use

  tickle 2074 8297
  

• When using the testdsp, there are two ways the simulate a burst:

  • (tickle 2049 8224 1; sleep 60; tickle 2049 8224 6) &
    

    will increase the count rate significantly for about 60 seconds, and then bring it back to normal.
  • For a more realistic burst,

    tickle 2049 8699 -19 8 4
    sleep 70
    tickle 2049 8700
    

    will turn on a burst at coordinates (-19, 8), with strength 4 times the background, and then turn it off after about 70 seconds.

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