Useful Spec commands during data collection

Motor nomenclature

• samx, samy, samz: sample stage motors. When we take data with the Maia detector, the sample is scanned in front of the detector.
• att: attenuator

Motor controls

Important note: the motors move along a relative set of coordinates that the user controls- the location is not directly related to the actual position of the stage. For this reason, we set software limits on the motion of the motors so that we do not (a) crash into the detector or (b) hit the physical limits of the stage motion.

Here are some useful commands for moving motors during your data collection.

• wsam: get all motor positions
  • Usage: "wsam" will report the high limit, current position, and lower limit of all three motors
• wm ("where motor"): get motor position
  • Usage: "wm samx" will report the high limit, the current position, and the lower limit of the x-motor
• umv ("you move"): moves motor to a specific coordinate
  • Usage: "umv samx 20" would move the stage to location 20 mm
• umvr ("you move relative"): moves motor relative to the current position
  • Usage: "umvr samz -15" would move the stage 15 mm in the negative direction
• tw ("tweak"): enters cycle where motor is moved in successive steps of the same size in the positive or negative direction
  • Usage: "tw samx 2" then asks for a sign- enter + or - to adjust the motor in steps of 2 mm in the positive or negative direction

Maia/data collection macros

• newfile: set up a new directory to save data
  • Usage: "newfile" will report back the current directory where data is saved and will ask you to give a new name for a directory. Give a name, hit enter, then hit OK when it asks if starting at 0 for the first blog file is ok.
• maia_scan: set up a scan. Input x coordinate, x step size, z coordinate, z step size, dwell time. positions are in millimeters and the dwell time is in milliseconds.
  • Usage: "maiascan 2 0.02 2 0.02 10" corresponds to a 2x2 mm square scan with 20 micron steps and 10 millisecond dwell time

-- LMS - 17 Mar 2016