Reports until 00:42, Wednesday 14 September 2016
H1 OpsInfo
sheila.dwyer@LIGO.ORG - posted 00:42, Wednesday 14 September 2016 - last comment - 22:58, Wednesday 14 September 2016(29683)
locking DRMI with low ground motion

Corey, Sheila

Tonight we have very low ground motion (useism band 10^-1 um/second earthquake band 10^-2um/second)

We have been using awggui to add an 8000 count sine wave at 0.1 Hz to the BS M1 LOCK L filter bank (which has a gain of 0.1).  This is helping us to catch fringes more often tonight, and we are manually ramping it off once DRMI locks.   This would be a good idea for operators who find themselves havign trouble locking DRMI in low ground motion.

To do this, use a terminal and type awggui.  Set it up like the attached screenshot.  It is a good idea to start with the gain (bottom middle) set to 0, hit set/run, then ramp the up to 8000 by hitting set in the gain box. 

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Comments related to this report
corey.gray@LIGO.ORG - 21:46, Wednesday 14 September 2016 (29713)OpsInfo

How does one manually ramp off this excitation?  I set gain from 8000 down to 0 & the ramp time from 1 to 10 and then hit the Set button, but I wasn't sure if this did anything (the excitation was still seen on the CDS Overview for H1SUSBS).  

I couldn't find instructions on killing/clearing testpoints in the wiki, but luckily Kiwamu was here and he knew the command:

>  tpclear 31 *

This cleared the excitation.

corey.gray@LIGO.ORG - 22:58, Wednesday 14 September 2016 (29714)

Sheila let me know that I could have taken care of the excitation by taking the gain from 8000 to 0 and then EXIT-ing the awggui session.  Will try this next time.