Reports until 13:23, Tuesday 13 June 2017
H1 ISC (CDS)
filiberto.clara@LIGO.ORG - posted 13:23, Tuesday 13 June 2017 - last comment - 14:28, Monday 19 June 2017(36855)
ALS Y WFS A Demod Readback Signals

WP 7031
alog 36571
 

A EL3104 analog input Beckhoff terminal was replaced from EtherCAT End Station Chassis 3. Alog 36571 reported CH3 & CH4 on terminal 7 showing an offset. Used a voltage calibrator to verify offset was from EL3104 terminal and not upstream.

Comments related to this report
jeffrey.kissel@LIGO.ORG - 16:14, Tuesday 13 June 2017 (36860)
Link 

Updated FRS Ticket 6024. Once a few days have past, we'll review the data to confirm success and the problem is fixed.
daniel.sigg@LIGO.ORG - 09:04, Thursday 15 June 2017 (36908)
Link

Trend over the past 8 days. Nominal adjusted to 21.5 dBm.

Images attached to this comment
jeffrey.kissel@LIGO.ORG - 14:28, Monday 19 June 2017 (36998)
Link 

J. Kissel
FRS Ticket 6024

I attach two trends of the past 12 days (three more than Daniel's plot above), and the past 365 days of these local oscillator read backs of the H1 ALS Y WFS A system. One can see from the 365 day trend that these ADCs would on drift at a rate of (the equivalent of) ~0.1 [dBm / month], so we're not going to be able to see if the problem is true fixed in these 6 days since the module was swapped.

So, my vote is that we close the ticket, but continue to monitor, and re-open if we find any drift in the future.
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