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Problem: ShaneAO WFS Y Misalignment
Recovery procedure if the WFS Y motors get out of alignment.
Not sure if the order correct (might have to change to POS mode and turn motors ON before changing the assembly to unlinked).
Also cannot recall if the Lenslet also halts when WFSY halts (recovery for the Lenslet is same as for when WFSX and WFSFocus halt).
These directions have been added to:
http://mtham.ucolick.org/techdocs/techref/ShaneAO/SAO_startup.html
under the motor homing section (even though this problem is not a homing problem, it is related).
Manifestation:
Solution/Recovery:
WFS Y has absolute encoders, so homing is simple as the stage does not move in the
process, but it is possible that the three Y motors get out of alignment with each
other and will need to be moved independently.
The unfortunate side effect of when the WFS Y motors halt due to misalignment
is that the WFS X and WFS Focus motor will also enter Halt mode.
The following procedure restores alignment between the Y motors:
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Visit the ShaneAO WFS Controls following (password protected) URL:
https://mtham.ucolick.org/ShaneAO/saomot7/
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In section WFS Cam Y: Examine second to last column to determine the Y1-Y2 and Y1-Y3 values.
If either value is over 500, it is necessary to change the Xmaxdif value (from shark or shred):
saomot.io ctrl7aux='Xdifmax=1000'
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In section WFS Cam Y: At the lower left, change Assembly to Unlinked.
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In Shane AO motor control GUI: Change to mode to Pos mode.
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In Shane AO motor control GUI: Select Turn motor on.
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Move a misaligned motor (either Y2 or Y3) a small amount (e.g. 100 counts) to make sure
the motor is moving and moving in the right direction (e.g. if Y1 - Y3 = -350 then the
direction and amount to move Y3 is -350 to get this motor back in alignment.
If the small move is successful, complete the move so that the difference is 0.
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Repeat above for the other axis if necessary.
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In section WFS Cam Y: At the lower left, change Assembly to Linked.
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Restore the Xmaxdif value to 500 (from shark or shred):
saomot.io ctrl7aux='Xdifmax=500'
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Move WFS Y stage to desired position.
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For both WFS X and WFS Focus, set mode back to Pos and select Turn motor on.
Then set them back to their desired positions.
Cause:
Associated Issues:
Change Log:
- 2020-11-24: First version.
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