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Entry  Tue Jul 6 10:47:07 2021, Paco, Anchal, Update, IOO, Restored MC 
    Reply  Tue Jul 6 16:35:04 2021, Anchal, Paco, Gautam, Update, IOO, Restored MC 
Message ID: 16238     Entry time: Tue Jul 6 10:47:07 2021     Reply to this: 16239
Author: Paco, Anchal 
Type: Update 
Category: IOO 
Subject: Restored MC 

MC was unlocked and struggling to recover this morning due to misguided WFS offsets. In order to recover from this kind of issue, we

  1. Cleared the bogus WFS offsets
  2. Used the MC alignment sliders to change MC1 YAW from -0.9860 to -0.8750 until we saw the lowest order mode transmission on the video monitor.
  3. With MC Trans sum at around ~ 500 counts, we lowered the C1:IOO-WFS_TRIGGER_THRESH_ON from 5000 to 500, and the C1:IOO-WFS_TRIGGER_MON from 3.0 to 0.0 seconds and let the WFS integrators work out some nonzero angular control offsets.
  4. Then, the MC Trans sum increased to about 2000 counts but started oscillating slowly, so we restored the delayed loop trigger from 0.0 to 3.0 seconds and saw the MC Trans sum reach its nominal value of ~ 14000 counts over a few minutes.

The MC is now restored and the plan is to let it run for a few hours so the offsets converge; then run the WFS relief script.

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