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Reports until 22:33, Monday 31 October 2016
H1 CDS
sheila.dwyer@LIGO.ORG - posted 22:33, Monday 31 October 2016 - last comment - 23:43, Monday 31 October 2016(31053)
ALS glitches

We are having a recurrence of the glitches that have been described in 30519 25523 22184

This time they are verry intermitent (only seem to happen about once every ten minutes), which would make it diffifcult to trouble shoot right now. 

Comments related to this report
corey.gray@LIGO.ORG - 23:43, Monday 31 October 2016 (31055)

Sheila said to watch time series of (4) ALS Channels for glitches.  They are:

  • H1:ALS-X-REFL_CTRL_OUT_DQ
  • H1:ALS-Y-REFL_CTRL_OUT_DQ
  • H1:ALS-C_TRX_A_LF_OUT_DQ
  • H1:ALS-C_TRY_A_LF_OUT_DQ

Have noticed some drops on these channels corresponding with locklosses while locking.

Sheila mentioned that previously this effect would go away on its own, so there may be hope.  Or, if the effect becomes more infrequent, if one can zip through the locking sequence and get to atleast RF_DARM, then one could be "home free".  (So far, the glitches have been taking H1 down at most steps starting at LOCKING_ARMS_GREEN up to PREP_TR_CARM.

I just finished an Initial_Alignment, and am now trying to see if we can get past RF_DARM and elude the dreaded ALS glitches.  (So far I am 0for5 in the last 20minutes of locking.)

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