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  Setup Procedure for X12B Motorized CrystalLogic Goniometer Head
Purpose The motorized goniometer head at X12B uses three jacks to position the crystal mounting platform in height and angle. When a crystal cap and pin are in place these motions translate into an x, y, and z crystal adjustment of sufficient range for automounter applications. Each jack may travel from 2mm to 10mm. The 5mm extension is the home position. Because the micro motors in this goniometer head have no limit switches or encoders, it is necessary to check its setup when putting the head into service.
For more info see the Gonio Tech Pages  

Procedure
  1. Connect goniometer head to its amplifier and plug in DC power supply.
  2. Launch the gonoiometer EPICS medm (see figure at bottom) using the path:
    ssh pxuser@x12b-h.nsls.bnl.gov
    cd epx_setup
    gonio_head
  3. Measure the platform extension adjacent to each jack as shown in the figure above. Use a caliper for precision. Be careful not to lift the spring-loaded platform of its jacks.
  4. Using the EPICS medm, drive the goniometer jacks until the distance measurements are all equal and 5mm. Typically several iterations are required to get it right.
  5. Disconnect power from the amplifier box.
  6. Drive the three jacks each to the 5 mm position (note: only EPICS 'moves').
  7. Reconnect power to the amplifier box.
  8. Mount goniometer head on the omega axis and make sure that its angular reading is the same as the current value in CBASS. Otherwise click-to-center will not work properly.

Goniometer Epics Medm
Gonio Jack 1, 2, and 3 are physical motors, Gonio X, Y, and Z are virtual motors.
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