# configuration file for camserverd#
# format is "key value"
# comments start with `#' and go to end of line
# blank lines are okay
# lines cannot be continued
poll_time 0.05 # main loop time quantum
sample_time 3.0 # sample time in seconds
driverpath /dev/astropci0 # location of driver
confpath /rotse/run/etc/ # .lod files location
lockpath /rotse/run/cfg/ # camera driver lockfile path
# boundaries of image subframe for statistical analysis
subframe_xmin 974 # minimum x-coordinate
subframe_xmax 1074 # maximum x-coordinate
subframe_ymin 974 # minimum y-coordinate
subframe_ymax 1074 # maximum y-coordinate
# boundaries for bias subframe
Along with the standard daemon settings, we also have a driverpath, confpath and lockpath. The driverpath specifies the location of the ARC camera driver. This is always set to /dev/astropci0. The confpath specifies the location of the DSP files to be loaded into the ARC camera hardware boards. These files should not be altered. The lockpath specifies where to put a lockfile when the camera driver is opened. If the camera readout crashes, this file is not removed. You must reboot the camera computer before removing the lockfile and restarting the daq system. Failure to comply with these instructions will result in a most hideous and painful death.3.1
After each image is read out, camserverd calculates some statistics for
the image subframe and the bias subframe, specified above. These statistics
include minimum, maximum, standard deviation, mean, and median, and can be a useful diagnostic for
image quality and readnoise level.
# FITS header parameters
cdelt 0.0009 # pixel scale (degrees)
# quality cuts on image subframe
stddev_cut 0.0 # minimum allowed std. deviation
max_min 30000 # highest minimum pixel value
docorr 0 # don't run internal correction
amplifier 1 # 0=left,1=right,2=both
symlinkpath /rotse/data/3a1/links/ # location of symlinks
The cdelt header value is for World Coordinate System (WCS) positioning in the fits file. The quality cuts are useful for saving disk space. If all the pixels in the central subframe are near saturation, the image is assumed to be ``bad,'' and only the header is written to disk. The system also calculates the number of saturated pixels in the image which can be a useful quick check of the focus quality. The amplifier variable specifies which amplifier should be used.3.2The readout time for dual-amplifier mode is 3s, but the ghosting of saturated pixels becomes a problem that we have not dealt with yet.
The camserverd system was written to be able to perform dark subtraction and flat fielding of the images in memory before they were written to disk. Unfortunately, this was too great a burden on the camera computer, and caused the system to become unstable. For this reason, docorr should not be turned on. Instead, a symbolic link to each image is put in the symlinkpath, where sexpacman.pl can find the files and process them automatically, as described in Section 8.2.1.