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SHARCS Problem: Aperture wheel nominally succeeded but...

Manifestation:

  • ShARCS Aperture wheel has trouble unambiguously arriving at some commanded positions (e.g. Pinhole-100um), reporting:

     
       Unknown, nominally succeeded but... 
       
  • Aperture wheel recalibrates succesfully and can be sent to the Open position reliably, but other positions are less reliable and the Pinhole-100um never settles unambiguously into its desired position (even after repeated recalibrations).

Solution/Recovery:

  • Set Aperture wheel MOE to On.
  • Command to desired position (e.g. Pinhole-100um).
  • Set MOE back to Default.
    • Cause:

      • Persistent positoning issue.
      • "Some days it just relaxes when the motor turns off and will still move just outside the range that is set to be on-target.
      • Temperature dependency not ruled-out.

      Associated Issues:

      • None.

      Change Log:

      2024-12-20: First version.


This document last updated (UTC): Tuesday 04 March 2025