== DMI Piston measurement procedure ==

* end of night stack  (turn off Quincy once structure is at CCAS)
* SAMS reference is set
* dome/louvers closed, AHUs running with chiller set to current internal temperature, no structure motion!!
* then run the wrapper script: {{{DMISweep.sh}}}
   * first it moves tracker to center
   * !Tip/Tilt metrology loop should be started (by the script, and stopped too), but not Active
   * script will ask to set !Tip/Tilt fiducial - click "Clear Fiducial" in TCS GUI - then press Enter
   * it will tell you which head it is using (DMI fiber switcher)
   * it will ask you to get the DMI head ready on DMI computer
      * KVM or remote access to DMI computer
      * DMI Server GUI
         * click on Exec Control to get a light green light on it
      * Dim LIS GUI:
         * click "Source Adjust"
             * if the source level percentage window is greyed out (after a restart), press Ctrl+F7
             * adjust top value of source level percentage until the top Measured Power is about 0.09 micro-Watts
             * center head is usually 15.8%, other heads are 12-13%
             * too small of a change may have no effect
             * Click "OK" when it's good
         * in Main GUI, click "Measure" and make sure signal amplitude is at least 1 V, or a little more is OK.
      * DMI Server GUI
         * click on Exec Control to turn it grey again
   * press Enter on script since the DMI is ready
   * script runs for about an hour as it measures the sequence of segments for this head
   * if it freezes on a mirror and doesn't get a measurement, check if PAS has crashed
      * can restart PAS, then "start metrology loop" on ~!Tip/Tilt camera tab, then Nathan's script should receive it and continue with the measurements
   * if tracker aborts or fails after the first head is done, probably better to give up
   * then it runs the second DMI head (you'll need to adjust the power); then runs third DMI head (adjust the power again)
   * script moves tracker to center and aborts it
   * after all three heads are finished, a matplotlib plot appears; close the window with the X in the corner to continue
* then can turn on the Quincy again
* click "Stow" on Structure and Dome tabs
* move tracker to low center (home) and abort it
* turn off Quincy once finished