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ALFOSC CCD3 known problems and their suggested solution

  • If you see error messages in the Talker like this:

    Command timed out looking for CCD3 program (alfosc-ccd3) to talk to (bus=161.72.5.255)

    Then re-run the command or script that caused the error. If it doesn't fix the problem shut down the observing system and start it again.

  • If the "Status delay" number on the ccd3 status display is red and is counting up then shut down the observing system and start it again. If it doesn't fix the problem, restart the "ccd3db" program as described here

  • If you see that all TCS and instrument FITS headers are missing from the images then

    1. restart the "fitswriter" program as described here

    2. restart the "ccd3db" program as described here

  • If you get this error in the talker:

    [ERROR]: alfoscdb disconnected from ccd3-alfosc.not.iac.es. This program must be restarted

    then restart the "ccd3db" program as described here

  • If you repeatedly and after each restart of the "fitswriter" program gets this error:

    [ERROR]: alfosc-ccd3-fitswriter disconnected from ccd3-alfosc.not.iac.es. This program must be restarted

    Then the value of one of the FITS keywords is likely causing problems for this program. The solution (for the technical staff!) is to find the offending keyword and comment it out of the fitswriter configuration file ccd3-alfosc:/etc/ccd3/fitswriter.conf" and restart program as described here

  • If you see images that has horizontal streaks from stellar images trailing towards the right (like this) then shut down the observing system, power the CCD controller off, wait 5 seconds and power it on again. After this you can start the observing system again and continue.
    The CCD controller is the blue box mounted on the right side of the ALFOSC CCD camera. See this photo

  • When windowing the ccd, set the X and Y size (with 'xsize' or 'ysize') before setting the beginning of the window (with 'xbeg' or 'ybeg').
    If you do the reverse and start an exposure, the software will freeze when starting to read out the image. If this occurs the image is lost and you have to restart the observing system.

  • When changing readout speed to 800 kpix/sec using the command 'readspeed 800' always remember to give the command 'ampl A' (or 'ampl B' if you want to use that amplifier) afterwards.
    If you do not, the bias level will be wrong.



Back to top Last modified: 29-Mar-2012