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Reports until 19:42, Sunday 31 January 2016
H1 ISC (Lockloss)
evan.hall@LIGO.ORG - posted 19:42, Sunday 31 January 2016 - last comment - 23:44, Monday 01 February 2016(25274)
Multiple BS coil switching locklosses today

We have had multiple locklosses today from the beamsplitter coil driver switching.

This is puzzling, since this step was largely unproblematic during the run.

Comments related to this report
jeffrey.kissel@LIGO.ORG - 02:29, Monday 01 February 2016 (25276)CDS, SUS
Link 

Opened FRS ticket 4325.

Unfortunately for the this study, the only BS's coil driver monitor channels stored are noise and voltmons, both of which are upstream of the output impedance network (so they don't measure the current effect of switching the "acquire" network off as is done here) *and* they're only stored at 1024 at the fastest.

I recommend we start by either
(a) installing an analog voltage breakout pick-off in-line with the M2 BOSEM chain down-stream of the coil driver to identify the amplitude of glitching which takes out the IFO's lock, and address from there, or
(b) Changing the h1susauxb123 front-end model to store the driver's FAST I MON at 16 [kHz]. (These can go in the commissioning frames, and also the noise and voltmon can be removed.)
richard.mccarthy@LIGO.ORG - 08:05, Monday 01 February 2016 (25277)
Link 

Starting to look at this but have a question before I start.
Why is the Ramp on UL  0sec and the other filter 10 Sec.
jeffrey.kissel@LIGO.ORG - 08:32, Monday 01 February 2016 (25282)CDS, SUS
Link 

Richard refers to the ramp time in COILOUTF bank; however the ramping between coils is performed by the new Ramp Matrix part not this bank. It's likely that this COILOUTF bank ramp times were "set" some long time ago (clearly more than 300 days ago!) and because it's not used for any ramping of control signals, it has merely remained untouched.
sheila.dwyer@LIGO.ORG - 23:44, Monday 01 February 2016 (25305)
Link

This problem has gotten worse and better in the past without any known cause, for example durring ER7 it was particularly bad.

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