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Starting and stopping the ALFOSC software in Sequencer mode


Starting the ALFOSC observing system

  1. Switch on the lisa screen (the switch is behind the screen to the lower right).

  2. On the XDMCP chooser click on the line
    ' Willing to manage'

  3. Log in with username 'obs'. Password is the standard one.

  4. Move the cursor to the left border of the screen and select the NOT logo icon (see the image below), click on it and login to Selena as user "obs" (passwd on the whiteboard). An Xephyr window appears with a blue background.

  5. Open a terminal window and type
    [obs@selena ~]$ startobssys alfosc
    A window will pop-up, asking for the TCS access code. Type it and press enter. If you type the wrong code a red error message appears and you must try again.
    All the ALFOSC software will now be started - the UIF, CCD3COMM and the FAPOL control. You will notice two terminals in blue/white colours with the title "ALFOSC Seq". These blue/white Sequencer windows (also called "seqterm"; use this command to get another sequencer terminal) are used to type-in the sequencer commands.
    The data will be saved in /data/alfosc and will have the format ALph160001.fits, where 'AL' is the image prefix for ALFOSC images, 'p' is for 2006, 'h' is for August, '16' is for the date 16 in the month and '0001' is a running number.

  6. The automatic ALFOSC observing log displays a listing of FITS headers for incoming data files. The System Talker lists incoming messages from the Sequencer. These two programs are displayed on the InfoSys monitor, and are automatically reset every afternoon. If you change between instruments you can change the obslog with the command e.g.:
    [obs@selena][ALFOSC]$ alfosc.showlog

  7. The software interfaces for the instruments are very similar looking. Many commands are common for all instruments and are executed from the sequencer window. For instance, type object name to specify a name that will be the object keyword in the fits header. To make an exposure, type expose t where t is the time in seconds. See the list of the most commonly used sequencer commands. For a complete list of all sequencer commands, view the Sequencer Reference Manual.

  8. In all the SEQUENCER windows change the working directory to the one assigned to your program, for instance
    [obs@selena][ALFOSC]$ cd ~/scripts/38-053
    as in this directory your ALFOSC observing scripts can be found, created, and executed.

  9. In an ALFOSC SEQUENCER window set the OBSERVER FITS header to hold the name of the actual observer(s):
    [obs@selena][ALFOSC]$ observer "Your Name"
    This will remove the RED "no-observer-specified" alert in the small "ALFOSC Run Selector" window, and will show the new value of the OBSERVER FITS header nicely in GREEN instead.

  10. In the Talker you will find information about the correct start of the different software components or a corresponding error. If any errors about a program not starting are seen, please shut down the observing system and start it again.
  11. Use and enjoy the Sequencer.

Click (twice) on the ScreenShot below to zoom in. On the right there is screenshot on the NOT logo icon where Xephyr window opens.
ALFOSC obssystem layout NOT icon

Shutdown the ALFOSC observing system

Important: Please leve the observing system open and running when you leave the telescope in the morning. This allows staff at sea-level to use it remotely for testing and diagnostics during the day.

The following procedure stops the ALFOSC observing system:

  1. In a terminal (not a sequencer) window type
    [obs@selena ~]$ shutdownobssys alfosc
  2. Wait for all the control programs to close.

  3. Close remaining windows manually.

Back to top Last modified: June 13 2023