Cameras

The DOT has 9 digital cameras and 1 analog camera. Of these, 7 are science cameras, each for a different filter, described at the DOT website. These filters can be used at the same time, and allows images to be taken at different wavelengths to be compared. Furthermore, some filters are tunable, allowing observers to take images at several points in the spectral lines. The DOT also has two full-disk cameras, of which one is analog and can only be used for guiding, while another one is digital and has a tunable Halpha filter in front of it. The last camera has a phase-diversity prism in front of it and is used for focussing.

The next informations displays the filter and camera names for all of the digital cameras.

List of cameras
Number	Computer	Camera	Filter
1	scott	KP-F100	Calcium
2	virgil	KP-F100	G-Band
3	alan	KP-F100	Blue Continuum
4	gordon	KP-F100	Barium
5	john	KP-F100	Barium Continuum
6	parker	ES4020	Red Continuum
7	tintin	ES4020	Halpha
8	beaker	KP-F100	Halpha FullDisk
9	penelope	KP-F100	PDFocus

The cameras should be placed in the right focus position according to the values obtained with the focus calibration procedure.

Restarting camera machines

Occasionaly, a camera machine will lock up. The most likely cause is that a fibertransceiver unit stopped working properly. The second most likely cause is the framegrabber card in the camera computer losing signal lock after a transient error in the fiber transception. It is also possible that the Ethernet connection has stopped working, or the computer has crashed altogether.

The symptom is either a red error message in the GUI, or its status is still green, but the camera image is clearly corrupt or not showing updates anymore. In case of the ?PD Focus or FullDisk cameras, the IDL pd_focus program or the guider is showing a black image (although his can also happen if you are pointed away from the Sun, or exposure is set too low).

The solution is:

On jeff, start a terminal window (press CTRL-ALT-T).
Look in the above table to find out the name of the computer belonging to the camera.
Type: ssh root@computername (replace computername with the name from the table of course).
If nothing happens for ten seconds or an error message appears that it could not connect, reboot the machine:
- Press the reset button, or if it cannot be found, press the power button until it powers down, wait ten seconds, and turn the power back on.
- Wait 10 minutes for the computer to finish booting.
- If the camera image is still not appearing correctly, try running ssh again.
If you have logged in succesfully, run the following command: invoke-rc.d dot-ccd restart
Wait 30 seconds.
If the problem is with the ?PD Focus camera, stop the pd_focus program and restart it.
If the camera image is still not appearing correctly, type invoke-rc.d dot-ccd restart again. This might have to be repeated lots of times.
If nothing helps, find or call DOT staff, and in the mean time try to continue without this camera.
Close the terminal window by typing exit or pressing CTRL-D.