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Entry  Wed Mar 5 19:27:24 2014, manasa, Update, IOO, MC calmed down 
    Reply  Thu Mar 6 09:47:11 2014, Steve, Update, IOO, MC trend of 20 days IOO_20days.png
    Reply  Thu Mar 6 19:17:05 2014, manasa, Update, IOO, MC calmed down MC_spots_Mar6.png
       Reply  Fri Mar 7 16:56:17 2014, steve, Update, IOO, IOO qpds centered IOOqpdCentered.png
          Reply  Mon Mar 10 09:28:48 2014, steve, Update, IOO, IOO pointing 2 days IOOpointing2d.pngmorningseconds.png
             Reply  Mon Mar 10 12:49:27 2014, Jenne, Update, IOO, PMC input pointing misaligned 
Message ID: 9701     Entry time: Thu Mar 6 19:17:05 2014     In reply to: 9695     Reply to this: 9704
Author: manasa 
Type: Update 
Category: IOO 
Subject: MC calmed down 

Quote:

The IMC has not been behaving well since this morning and totally not happy when Q was finishing his measurements. The WFS servo had large offsets in pitch. Looking back at the trend and using ezcaservo to restore the suspensions did not help.

I realigned the IMC and brought TRANS SUM to ~18000 and MCREFL to < 0.5. The spot positions are not very good; nearly 2 mm off in pitch on MC1 and MC3. But after the alignment of MC, the WFS servo offsets were below +/-20.

The MC has been locked stably with WFS servo ON for the last few hours.

P.S. I did not touch the WFS pointing or reset the WFS offsets.

MC remained locked with WFS enabled all through last night and this morning. Koji dropped by and looked at the MC. The MC WFS servo, though stable, was at the edge of becoming unstable. This was because I did not touch the WFS pointing on the QPDs yesterday after realigning. So I recentered the WFS, reset the WFS filterbank offsets and reenabled the servo.

I measured the spot positions on MC mirrors for reference.

Spot positions in mm (MC1,2,3 pit MC1,2,3 yaw): [1.405767579680834, 0.79369009503571208, 1.3220430681427462, -1.2937873599406551, -1.1704264340968924, -1.2518046122798692]

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MC_spots_Mar6.png
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