Changes
SHOC
,/* Technician's guide */
The [http://shoc.saao.ac.za SHOC website] may well have more extensive detail about this instrument.
===IMPORTANT NOTES===
== Change Log ==
'''Most recent changes at the top'''
* '''v1.4.4 Release date 5 December 2018<br>'''
** Bug: Camera user interface works without any filter wheels
** Feature: Display filter wheel names on the user interface
* '''v1.4.3 Release date 25 July 2018<br>'''
** Bug: Fixed GPS antenna reference "off" bug by assigning per-telescope locations
** Feature: Added a button to set GPS start time 30 seconds into the future (uses web browser operating system's time so make sure that your time zone is SAST)
* '''v1.4.2 Release date 3 January 2018<br>'''
** Feature: Better error reporting
** Feature: TCS info now available when mounted on the 40-inch
* '''v1.4.0 Release date 23 November 2016<br>'''
* If using external triggering, select the GPS tab <span style="color: red">'''(1)'''</span>
* Ensure timing is valid <span style="color: red">'''(2)'''</span>.
* Set the Programmed Output Pulse (POP) parameters (mode <span style="color: red">'''(3)'''</span>, pulse width <span style="color: red">'''(4)'''</span>, start date <span style="color: red">'''(5)'''</span>, start time <span style="color: red">'''(6)'''</span>(<strong>NOTE</strong>: the "now + 30 seconds" button uses your browser's time so make sure your operating system is set to local time), trigger interval <span style="color: red">'''(7)'''</span>) and click apply <span style="color: red">'''(8)'''</span>. The status should change to pending <span style="color: red">'''(9)'''</span>.
* The recommended default pulse width is 10 microseconds.
When running a series of exposures on the same target with different filters it
can be useful to make use of the automated acquisition mode on the camera tab.'''NOTE: SCRIPTING ALWAYS USES THE INTERNAL TRIGGER'''
[[File:scripting_1.png|1000px]]
==Data Transfer==
There is an automatic transfer of data from the instrument to the file servers in Sutherland and Cape Town, every morning at 7:30. So you should not need to worry about the security of your data. However, you'll still need to access your data! We describe here how to do this. There are two ways to transfer get the data: (1) directly to your computer from the instrument PC or (2) onto from the SAAO storage area network (SAN). The data are automatically copied to the server every morning (at 7:30am).* To use method (1) To transfer data directly to your computer, use the command line.:
** Open a shell on your local PC (Putty if you're using Windows or a bash/tcsh/sh if on Mac or Linux)
** Copy the data using the following command, depending on the telescope:
rsync -avzP shoc40in@shoc40in.suth.saao.ac.za:"/data/40in/shd/2016/0503/*.fits" /LocalFilePath
rsync -avzP ccd74@astro.suth.saao.ac.za:/data/telescopedata/74in/sh?/<YYYY>/<MMDD>/*.fits /LocalFilePath
rsync -avzP ccd40@astro.suth.saao.ac.za:/data/telescopedata/40in/sh?/<YYYY>/<MMDD>/*.fits /LocalFilePath
* Below this, the readout speed and preamp gain may be set.
* Below this, the readout speed and preamp gain may be set.
* The last setting is the Electron Multiplying (EM) gain. <span style="color: red">NOTE: DO NOT USE ELECTRON MULTIPLYING MODE UNLESS YOU HAVE SPECIFICALLY OBTAINED PERMISSION FROM DR AMANDA GULBIS SICKAFOOSE TO DO SO, AND YOU UNDERSTAND HOW AND WHEN TO USE IT. PERMANENT DAMAGE TO THE SENSOR CAN RESULT FROM INCORRECT USAGE. If you are using EM mode, choose the EM output amplifier, and then select a gain. BEGIN WITH LOW GAIN VALUES, BECAUSE IF THERE IS TOO MUCH SIGNAL''' YOU CAN DAMAGE THE CAMERA.'''</span>
* When setting the horizontal shift speed, preamp gain and (if using EM mode, the EM gain), note the following: Higher readout speeds allow for shorter exposure times, but at the expense of noisier data, while higher electron to ADU gain values decrease the dynamic range. Read noise and electron to ADU gain values for each mode are provided in the PDF manual. In addition to this, it should be noted that as it takes about 6 milliseconds for the top-most pixel in the frame to be shifted to the storage area and SHOC does not have a shutter. The top row of pixels in each frame will have an exposure time of about six milliseconds longer than the bottom row. Consequently although it is possible (with enough subframing and binning) to expose for less than a hundredth of a second, this is inadvisable for the above reason. Finally, as indicated above, the 1MHz CON and EM modes are both 16bit. What this means is that the mode will reach saturation at 2^16 = 65536 counts. On the other hand, the 3 MHz CON and EM and 5,10 MHz EM modes are all 14-bit modes and saturate at 2^14 = 16384 counts. As the saturation limits of each mode will also depend on the electron to ADU gain, tables in the printed manual give the saturation limit in both counts and electrons for each mode.
* To get a quick view of the images that will result, press the "Preview" button. Images will be displayed in the left-hand display panel. Press "Stop" when you're done.
''This functionality should be available on the 74", the 40" and the new 1m. It has only been tested on the 74".''
The idea is to take a long, GPS-triggered data cube with SHOC at high cadence, while running the LED at 1 PPS (which has a longer pulse on the minute and can thus be used to test absolute timing accuracy).
*The dome and mirror covers must be OPEN for this test to work. (The GPS needs to get satellite signal, and the LED must be seen through the light path.)
*There is an LED mounted in the telescope optical path that can be used to independently verify SHOC timing. Log into the following website:
To use the command line interface:
** Fire up a terminal
** $ ssh <user>@<shocndisbelief|shocnawe>.suth.saao.ac.za** $ cd /home/ccd/programming/shoc/shoc/-gps** $ python -cli.py
** The commands in the cli are help, status, pop, mask, bias, timing_mode and location. Use "help <command>" for more information.
** The timing_mode option makes the GPS use static or dynamic mode.
'''Note When You SSH After you ssh after the CNAME Changechange'''
Note: This change will result in a warning if someone tried to SSH into the machine - this is safe to accept.
Are you sure you want to continue connecting (yes/no)? yes
'''Possible CNAME Changeschanges'''
With the CNAME setup below, both the shocndisbelief and shocnawe can be connected in the new '''1m'''. Please ask the IT standby person to help you with this DNS setup. At this moment '''only''' the '''shocnawe''' will be moved between the 40inch and 74inch. The '''shocndisbelief''' is in the '''1m''' and will '''not''' be moved between the 40inch and 74inch.
'''How It It Configured Nowto configure'''
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'''Can Be Added If Requiredbe added if required'''
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Run the script shocboxswitch.sh. The default option reverts to the standard mapping between shoc computers and telescopes. If the default is not chosen , you'll be prompted for the name of the telescope the shoc computer is being mounted on.
* Check the log entry to make sure the configuration was changed to the telescope you chose. In a terminal type:
less /var/log/shoc-camera.log
[[image:Camera-log.png|500px]]
* Check and make sure that the configuration file points to the telescope name that you chose. In a terminal type:
less /etc/init/shoc-camera.conf
* Take test data to make sure the data is written to '''/data/<telescope_name>/<instrument_name>/YYYY/MMDD/'''.
==Unmounting SHOC==
