End of night

  1. Position the filter wheel to the block position.

  2. To break the network connection, press the Close Connection button in the PC Connection menu, and answer yes to the prompt menu that appears.

  3. Exit the SCACQ and SCDISP programs by clicking the right button on the title bar of each window and selecting the Quit option. Closing the SpectroCam programs ensures that the log file is flushed to disk before starting the backup; there is also a button in the log entry window to do this.

Backing Up Data to Tape

  1. We use the Unix tar program to back up data to exabyte tape. Make sure that your 8 mm tape (data quality preferred, not the cheap stuff), is write-enabled, then put it into the drive. From a command tool while you are still logged in as scuser, type

    scuser> echo $TAPE

    to display the TAPE environment variable. It should be set to /dev/rmt/0n, the name of the tape device. The mt and tar commands described below use this environment variable to drive the tape device. If it is not set properly, type

    scuser> setenv TAPE /dev/rmt/0n

    to set it.

  2. Type

    scuser> mt stat

    The mt command is the Unix command to position and monitor the status of a tape device. You should see a message indicating you are at file 0. If this is a new tape, you can begin writing data immediately. If the tape is not new (you have already recorded a tar file on it, and you want to append a file to the end), type

    scuser> mt eom

    This variant of mt positions the tape at the end of media. You can use mt eom on what you believe is a new tape to make absolutely sure there is no data already on it -- mt will leave a new tape at the beginning. As a last check, re-run mt stat after mt eom is complete, and make sure the displayed file number corresponds to the expected value. For example, if there is 1 file on tape, mt stat should print that the tape is positioned at the beginning of file 1 because the file numbers are zero-based.

  3. Change to the disk that conatins your data directory (for example, /scr1). The data for the night will be located here -- use the ls command to display the subdirectories. To back up the data in the subdirectory sep25, for example, simply type

    scuser> tar cv sep25

    The c option means create a new file, and v stands for verbose -- you should now see the names of all the files in the subdirectory printed on the screen as they are backed up to tape.

  4. When the backup is done, type

    scuser> mt offline

    to rewind and eject the tape.

  5. With this method, the files on tape will be labeled like ``./sep25/sc001'', and so on. To get them off the tape, simply use the command

    yourmachine> tar xv

    (assuming the TAPE environment variable is correctly set on your machine). The tar program will automatically create the ``sep25'' subdirectory in the directory from which it is run, and put all the files in there.

Final Shutdown for the Night

  1. The workstation screen will lock after 30 minutes. You can hit the "lock" icon on the Front Panel taskbar if you don't want to leave your monitor alive for that time. You can logout with the "EXIT" icon.

  2. Like all Unix machines, GRB should not be powered off without properly syncing the file systems. We usually leave the machine running during the day, but if you need to shut it down the proper procedure is described in Chapter 2.

  3. On the Cornell chopper box, turn on the flip mirror power and move the mirror to the stowed position. This helps keep the mirror clean. Turn the power off after the mirror has retracted.

  4. On the f/70 secondary control panel, move the lid switch to the closed position. You should hear a loud tone after several seconds indicating the lid has closed.

  5. In the Cass. cage, turn off the GSM motor power. Leave the sensor power on so the electronics will remain at a stable temperature.

  6. Turn off all three detector power supply switches, starting with the leftmost (CoAdder) switch.

  7. Turn off the stepper motor controllers.

  8. Type ex from the PSYS main menu to exit the program. Answer yes to the two queries to confirm that you want to exit and to save the current status in the save file.

  9. You can turn the PC off, but in cold weather it may be better to leave it on.