LRS2

The LRS2 instrument is controlled by the lrs2.as.utexas.edu system. These notes assume one is logged in as the hetdex user.

Startup

Linux init scripts are used to start the data acquisition server and temperature monitor.

$ sudo /etc/init.d/camra_server_start.sh
$ sudo /etc/init.d/camra_monitor

Taking Exposure

There are many ways to take an exposure, the simplest uses a Python script to issue the expose command.

$ cd $HET_SRC_ROOT
$ ./camra/testing/lrs2.py 'expose( seconds=20, observation=1234, exposure=1, x_binning=1, y_binning=1, type="sci" )'

The exposure command will return once the readout has started. The output FITS files will be available 40-50 seconds after that, depending on binning and disk I/O. The return string of the expose command provides the output directory for that exposure.

The exposure time is in the "seconds" parameter (minimum of 15).

Observation and exposure determine the directories under which the data are grouped. An example output directory structure might be

/opt/data/20160309/lrs20000023/exp01/
                              /exp02/

So here two exposures are grouped under the observation number 23 taken on 20160309.

The combination of observation/exposure must be unique for the UTC date. The agreed upon types are "sci", "cmp", "zro", "flt", "drk", "tst".

Checking Hardware Status

$ cd $HET_SRC_ROOT
$ ./camra/testing/lrs2.py 'get_hardware_status( update_state="true" )'

The status may be queried mid-exposure by omitting the update_state parameter.

Calibration Script

A prototype calibration script is available that can calibrate VIRUS and LRS2. This script attempts to expose all known supported FCU configurations as well as darks and biases. The console output of the script provides a log of the calibration process so it is recommended to capture the output to a log file via tee.

$ cd $HET_SRC_ROOT
$ ./integration/cal.py -i lrs2 -l lamp1a lamp1b lamp5b ldls -o 101 -n 11    2>&1 | tee lrs-cal.log

The above will expose the lamp1a lamp1b lamp5b ldls (Hg Cd Qth ldls) as observation 101 (and subsequent numbers) and take 11 darks and biases at the end. This is the standard calibration sequence for LRS2.

Calling the script with --help produces more information:

$ cd $HET_SRC_ROOT
$./integration/cal.py --help
usage: cal.py [-h] -i {lrs2,virus} [-l LAMPS [LAMPS ...]] [-o OBS] [-N NLAMP]
              [-n NDARK] [--dry-run]

VIRUS and LRS2 Calibration Script.

optional arguments:
  -h, --help            show this help message and exit
  -i {lrs2,virus}, --instrument {lrs2,virus}
                        Instrument to expose. Must be virus or lrs2
  -l LAMPS [LAMPS ...], --lamps LAMPS [LAMPS ...]
                        List of lamps to expose, e.g. '-l lamp1a lamp3a'. The
                        default list is all lamps: ['lamp1a', 'lamp1b',
                        'lamp5b', 'ldls']
  -o OBS, --obs OBS     Observation number to start with, defaults to 101.
  -N NLAMP, --nlamp NLAMP
                        Number of exposures to take for each lamp, defaults to
                        1. Give 0 for no exposures.
  -n NDARK, --ndark NDARK
                        Number of darks and biases to take, defaults to 11.
                        Give 0 for no exposures.
  --dry-run             Print actions without executing commands on the
                        hardware.

The list of lamp combinations is spelled out in a table at the beginning of the script. That table also sets the exposure times and warmup times for the lamps.

Use the --dry-run option to see what the script would do given some options without actually executing any commands on the hardware.

Additional Help

Help for the complete set of CAMRA commands can be obtained by issuing a 'help()' command to the CAMRA subsystem.

$ cd $HET_SRC_ROOT
$ ./camra/testing/lrs2.py 'help()'