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October 30, 1997

5

3.2

QCDCOM Setup and Operation

The qcdcom program should be run from the directory where you want your data to be written,
though this can be changed from within qcdcom using the

cd

command. So execute the following

commands:

% cd /scr/data

(or wherever your data should go)

% qcdcom

When qcdcom is started, it initializes communications with the parallel interface, allocate memory
into which to read IR array images, and read enough from the DSP memory to get an idea of the
status of the DSP code. Qcdcom also initializes itself for readout size and binning parameters from
the numbers it reads from the DSP. Since qcdcom runs separately from the DSP computer and saves
its own parameters, qcdcom can be terminated and then restarted without disturbing the DSP.

At startup qcdcom prints a short message identifying the program, and display the filters installed
and the current filter and pupil position. It will also try establishing communication with the camera,
and will give a warning if it fails. If the camera has not been initialized after powerup, or if for some
other reason communications have failed, the DSP code will have to be downloaded to the camera.
This is done with the

df

command. You should do this at the beginning of your observing run to

make sure the correct code is running. The command to download the current standard DSP code is
the following:

>

df quirc

Occasionally the download will fail if the camera is in some undetermined state, and a reset will need
to be done. The DSP reset is a red button on the white controller box mounted on the dewar. Usually
pressing this once and waiting several seconds before retrying the download will work. Once the
download has completed, the

sync

command can be used to see if the camera communications are

OK. You can use the

sync

command at any time to verify that qcdcom and the DSP computer are

talking. Once the main DSP program has been downloaded with the

df

command, the utility board

program must be downloaded using the following command:

>

du util

This loads the code that performs the filter wheel and pupil motions.

Next you should set the way files will be named on the disk. Files are named using a prefix with the
frame number appended, thus you should set the prefix using the

fp

command and reset the running

file number using the

fn

command (typically to 1 when you start up). For example, to have files

named qrc.001, qrc.002, etc.:

> fp qrc.

> fn 1

Note you must specify a trailing dot in the file prefix if you want one.

You will also want to set the exposure parameters using

auto

at this time. Since you may inherit

parameters from the previous observer, you should make sure they are set to the default values, which
are correct for most observing. One easy way to do this is to use the

init

command described

Summary of Contents for QUick Infrared Camera

Page 1: ...Observer s Guide for QUIRC K W Hodapp J L Hora M R Metzger University of Hawaii October 30 1997...

Page 2: ......

Page 3: ...ith QUIRC The qcdcom program controls taking exposures and writing data in FITS format to disk operates the moving parts of the instrument such as the shutter filter wheel and pupil mask communicates...

Page 4: ...ation differences for integration times less than 1 second Therefore short exposures should be avoided particularly when exposing dome flats it is far better to dim the lights with the domelight dimme...

Page 5: ...elow assume a PSF of 0 5 arcsec FWHM Table 2 QUIRC Sensitivity UH 2 2m Telescope Filter Point SRC Mag Mag arcsec2 Jy ADU 1 sec J 18 6 17 9 1 052e 6 H 17 8 17 1 8 295e 7 K 16 2 15 5 9 622e 7 H K 18 6 1...

Page 6: ...ted image display capability A separate program should be used to display the data One option is to use the viewfits program vf This is a display program developed by Tony Denault at the IRTF that dis...

Page 7: ...ode is running The command to download the current standard DSP code is the following df quirc Occasionally the download will fail if the camera is in some undetermined state and a reset will need to...

Page 8: ...rash for any reason the parameters it reads in may be old and you may need to set them again Typically only resetting the file number is necessary 3 3 Taking exposures For each object you are observin...

Page 9: ...telescope and guide probe and turns the guider back on On the 88 this communicates with Atlas and MiniOtto over the ethernet to perform the guider movements and on CFHT commands are sent over a seria...

Page 10: ...6 H K dual 1 8 m 2 794 20 6 6 1 7 H2BP23 2 12 m 0 914 2 1 7 1 8 2260BP60 2 260 m 2 794 20 6 8 2 1 1560BP120 1 56 m 9 2 2 1710BP120 1 71 m 10 2 3 1 989BP50 1 989 m 11 2 4 1 506 60 1 506 m 12 2 6 1 107...

Page 11: ...th auto or the shutter will not open Also note that you should always do only one filter DARK followed by exactly one filter BACK always in pairs otherwise the filter wheel will get lost and require a...

Page 12: ...chop image and displayed in vf Therefore the observer can take focus frames acquire and center the object etc without saving all the images as separate data files This avoids filling the disk with use...

Page 13: ...P initialization commands In general you will need to initialize the DSP processor in the Leach electronics after power up or after a DSP reset because its cold reset state is not appropriate for runn...

Page 14: ...rform first data read of double correlation pair store image in memory 4 Turn off output amplifiers 5 Open the shutter and wait for a predetermined exposure time 6 Close the shutter 7 Turn on output a...

Page 15: ...e double correlated read on off Controls whether the device is read out before and after the shutter opening or only after If reading before and after the difference between the two are taken and this...

Page 16: ...o stay open slightly longer The exposure time recorded in the header however will reflect the true amount of time the shutter was open filter hnum commandi Set filter This command selects the filter s...

Page 17: ...fp q940811 go h num i 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 predeterm...

Page 18: ...resulting image to a disk file set hparami n Set parameter Certain program parameters can be set or unset with this command To set a param eter for example save one issues the command set save To uns...

Page 19: ...direct access to the DSP computer hall hnloopi Read Hall sensors read the Hall effect sensors nloop times The filter wheel 1 sensor is displayed and depending on the position of the switch either the...

Page 20: ...en data is used as a seed for a random number generator and 65536 words of random data are sent per loop diag l3 hcnt fr cg data i Timing board loopback test Loopback test with timing board in place M...

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