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40m Log |
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Sat Nov 12 01:09:56 2016, gautam, Update, LSC, Recovering DRMI locking
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Wed Nov 16 03:10:01 2016, gautam, Update, LSC, DRMI locked on 1f and 3f signals
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Wed Nov 16 08:14:43 2016, Steve, Update, LSC, DRMI locked on 1f and 3f signals
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Mon Nov 21 14:02:32 2016, gautam, Update, LSC, DRMI locked on 3f signals, arms held on ALS
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Wed Nov 23 16:21:02 2016, gautam, Update, LSC, ITMY UL glitches are back
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Mon Nov 28 10:27:13 2016, gautam, Update, SUS, ITMY UL glitches are back 
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Tue Nov 29 11:07:37 2016, Steve, Update, LSC, ITMY UL glitches are back
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Wed Nov 30 01:47:56 2016, gautam, Update, LSC, Suspension woes
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Wed Nov 30 17:08:56 2016, gautam, Update, LSC, Binary output breakout box removed
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Thu Dec 1 02:19:13 2016, gautam, Update, LSC, Binary output breakout box restored   
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Thu Dec 1 08:02:57 2016, Steve, Update, LSC, glitching ITMY_UL_LL
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Fri Dec 2 11:56:42 2016, gautam, Update, LSC, MC1 LEMO jiggled 
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Mon Dec 5 15:05:37 2016, gautam, Update, LSC, MC1 glitches are back
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Thu Dec 8 10:13:43 2016, Steve, Update, LSC, glitching ITMY_UL has a history
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Message ID: 12657
Entry time: Fri Dec 2 11:56:42 2016
In reply to: 12654
Reply to this: 12664
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Author: |
gautam |
Type: |
Update |
Category: |
LSC |
Subject: |
MC1 LEMO jiggled |
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I noticed 2 periods of frequent IMC locklosses on the StripTool trace, and so checked the MC1 PD readout channels to see if there were any coincident glitches. Turns out there wasnt BUT - the LR and UR signals had changed significantly over the last couple of days, which is when I've been working at 1X5. The fast LR readback was actually showing ~0, but the slow monitor channel had been steady so I suspected some cabling shenanigans.

Turns out, the problem was that the LEMO connector on the front of the MC1 whitening board had gotten jiggled ever so slightly - I re-jiggled it till the LR fast channel registered similar number of counts to the other channels. All looks good for now. For good measure, I checked the 3 day trend for the fast PD readback for all 8 SOS optics (40 channels in all, I didn't look at the ETMs as their whitening boards are at the ends), and everything looks okay... This while situation seems very precarious to me, perhaps we should have a more robust signal routing from the OSEMs to the DAQ that is more immune to cable touching etc...

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