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Detector Operation (Operations Report)
Nenci - 23:01 Wednesday 14 November 2018 (43579) Print this report
Operator Report - Evening Shift 14/11

The first part of the afternoon has ben dedicated to the suspension tuning, at about 17:05 UTC started the second part of the shift dedicated to the squeezer optimization.

17:27 UTC - OMC - we had again troubles to lock the OMC1, therefore we contacted expert oncall that fixed the problem.

18:20 UTC - ITF locked in LowNoise3.

21:45 UTC - SUSP - DMS showed red flag for the NE electronics (picture attached), I contacted the oncall expert who noticed a board switched off (probably by itself)... he re-started it remotely with the ITF locked without major problems.

22:00 UTC - Commissioning Mode stopped, activity still in progress (ITF left locked in LowNoise 3).

All the subsystems worked properly, no particular problems or events to report.

Images attached to this report
Comments to this report:
mwas - 7:54 Thursday 15 November 2018 (43582) Print this report
Yesterday evening around 17:30 UTC the locking issue was not related to the OMC, but to the automation of the slow shutter.
ITF_LOCK steps are overloaded, in each of the ITF_LOCK state several transitions are made.

LOCKING_OMC1_B1s2_DC corresponds to adding a dark fringe offset, adjusting ITF alignment loops, opening the slow shutter, locking OMC1, changing DARM error signal from RF to DC

Please also look at the state of other metatron nodes. DET_MAIN metatron node should have been displaying a flashing yellow message:
"Too many steps done and shutter not open, waiting for manual action"
As a consequence the OMC never received the request to lock. OMC_LOCK was not in the ACQUIRE_OMC1 state, but in TEMP_CONTROLLED.

Figure 1 shows the slow shutter opening, the figure in the lower right pane is a monitor of the current applied to the slow shutter.
Normally it should be in steps like in the second half of the time series, as metatron sends request for motion, with gaps in between them so we can count them.
In the first half there is a continuous motion of the slow shutter, which probably means the metatron cycles were too fast (less than 0.6 seconds?), and half of the motion requests were not received by the slow shutter rotator because send when the motion from the previous request was still happening. This would explain why the automation arrived at the safety limit of the maximum number of steps, as have of the steps requested were not done.

I have increased this morning the maximum number of step safety limit from 40000 to 45000.
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