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Entry  Wed Sep 30 02:01:28 2009, rob, Update, Locking, week srmcpu.png
    Reply  Thu Oct 1 15:42:55 2009, rob, Update, Locking, c1susvme2 timing problems update srmcpu2.png
       Reply  Fri Oct 2 14:52:55 2009, rana, Update, Computers, c1susvme2 timing problems update Untitled.png
          Reply  Fri Oct 2 15:11:44 2009, rob, Update, Computers, c1susvme2 timing problems update update srmcpu3.png
             Reply  Mon Oct 12 14:51:41 2009, rob, Update, Computers, c1susvme2 timing problems update update update srmcpu.png
Message ID: 2027     Entry time: Wed Sep 30 02:01:28 2009     Reply to this: 2037
Author: rob 
Type: Update 
Category: Locking 
Subject: week 

It's been a miserable week for lock acquisition, with each night worst than the last.  The nadir was around Sunday night, when I couldn't even get a PRM to lock stably, which meant that the auto-alignment scripts could not finish successfully.  It now appears that was due to some XYCOM mis-settings. 

We've also been having problems with timing for c1susvme2.  Attached is a one-hour plot of timing data for this cpu, known as SRM.  Each spike is an instance of lateness, and a potential cause of lock loss.  This has been going on for a quite a while.

Tonight we also encountered a large peak in the frequency noise around 485 Hz.  Changing the MZ lock point (the spot in the PZT range) solved this.


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