Set the raw position of the motor without moving it

Setting the motor position/offset

Note that this applies to multiple motor types but not McLennans

Sometimes it is desirable to change the reported position of the motor without it physically moving, effectively changing the origin of the axis. This can be achieved through EPICS by applying an offset to the reported motor position and by setting the position in steps in the motor. TO do this:

  1. See if you can home the axis instead of setting the value directly

  2. Ensure the motor IOC is running

  3. Put the instrument in to manager mode if it is not already in the mode

    • Menu bar: IBEX -> Manager mode

  4. Go into the Motors perspective in the client

  5. Bring up the OPI for the desired motor by double clicking the relevant square in the table motor summary opi

  6. Click on More details...

  7. In the Calibration section,

    • ensure that it says Frozen above the offset box

    • switch Cal from use to set

    • motor details Calibration section Set pressed

  8. Either

    1. Change the Off field to apply an offset to the current position

    2. Change the current position directly by changing the MoveAbs User field in the Drive section motor details driver section

  9. Don’t forget to switch the Cal field back to Use once you’re done or the motor won’t move. motor details Calibration section Use pressed

  10. Finally leave manager mode