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October 30, 1997
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fw wheel# position Set filter wheel to position
Set the specified filter wheel (1 or 2) to a specific position (1 through 8). For
example, one would give the command fw 2 3 to move filter wheel 2 to position
number 3. This command is normally not used, the fi command (see above) is used
to set the standard filter positions. However, this command could be used to set some
non-standard combination of filters, such as the K filter and a narrowband filter.
fn fileno Set running file number
Qcdcom writes files of the form filename.xxx, where xxx is a file number. fn
allows you to specify the file number. Qcdcom uses the current file number as a prompt,
and automatically increments the file number as each file is written.
focus number Do focus image
focus performs a focus integration, with the number parameter being the number
of focus integrations in one detector readout. The shutter is open and closed “number"
times, pausing between each integration for a focus change and movement of the object.
fp prefix Set file prefix
fp allows you to specify what the output file name will be. Qcdcom expects to write
a file of the form prefixNNN, where NNN is the frame number. fp is how you specify
prefix. Note that if you want a decimal point as a separator you must specify it.
Qcdcom’s default for a file prefix is qrc..
Example: fp q940811.
go num Start exposure
Go is the command to take an exposure. As described above, according to the param-
eters which are set, go may reset the chip, open the shutter and close it a predetermined
time later, read out the data into memory, write the data to disk, and set the controller
into idle mode. An exposure which has been started with go and Unix timing (et) can
be interrupted by control-C. This will close the shutter and return you to the qcdcom
command level. You can then alter parameters while you are in the paused mode. For
example, you can change the exposure time with et, or the eventual output file name
with fp or fn. You can set or unset automatic flags to specify what go will do when it
finishes. If you want to continue the exposure, you can reissue a go command. If you
want to read out the device, you can issue an rc command. If you want to abort the
exposure, use the clear command. You can take multiple identical exposures with the
num argument.
idle Put camera in idle mode
idle starts an infinite loop of resetting the detector every 5 seconds. It is a good idea
to leave the system in this state when not observing, so that the detector does not saturate.
If the auto idle mode is set, the camera is put into idle mode after every exposure.
init Reset all “auto” parameters to defaults
This command initializes all the program parameters to a default state that is appro-
priate for most observing. One can use this as an easy way to reset the program when
starting out after another observer has been using Quirc.