TITLE:  Sep 15 EVE Shift 23:00-07:00UTC (16:00-00:00 PDT), all times posted in UTC

STATE Of H1: Observing

LOCK DURATION: 5hr48min

SUPPORT: Sheila gave a tip regarding if the 2Hz comb should re-appear to check the ALS Phase discriminator RF Mon and LO Mon to see if the counts have stopped moving. More about this can be found in her aLog. https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=21564

INCOMING OPERATOR: Nutsinee

Activity log:

23:31 Team out to swap the EndY EtherCat chassis 2

23:43 Sheila called from EY to confirm IFO state in order to begin work with EtherCat chassis.

00:17  Sheila called to say that they think they won.

00:18 Begin Locking

00:25 Team out of EY and headed back to control room.

01:00 IFO set to UNDISTURBED/Observing

01:17  I noticed the PCal lines missing

01:18 IFO set to UNDISTURBED/Observing

01:48 ETMY Saturation

02:19 ETMY Saturation

02:43 ETMY Saturation

02:51 ETMY Saturation

03:09 ETMY Saturation

05:33  poking around in GraceDB I noticed that there was a Gamma Ray Burst Alarm while the IFO was down.

End-of-Shift Summary: IFO remains locked and Observing at ~70Mpc. Seismic and wind activity remain quiet. MIcroseism had been steadily increasing over the last 22 hours but seems to have leveled off at around 2e-1. Occassional ETMY glitching (will be detailed in the end of shift activity log.

Sheila, Evan

Last night, we had a beckhoff problem at end Y that started at 5:44 UTC (alogs: 21555 and comments). 

The ESD high voltage remained on all night, even though the vacuum guages that are meant to turn it off were not communicating. 

The first screen shot shows the beckhoff readout vacuum guage (H1:VAC-EY_Y4_PT425_PRESS_TORR) , which was reporting a constant value all night since the start of the beckhoff problems.  It was alo reported as "valid" durring this time.  Before Fil, Vern Nutsinee and I went out to EY, Patrick and I were attempting to clear the beckhoff errors by reiniting all the modules.  This must have been partially sucsesfull around 18:33 UTC, when the pressure reading dropped to zero, the channel is no longer reported as valid, and the ESD high voltage gets turned off.  This is why we found the high voltage off even though it had been on all night. 

One other concerning thing is that the values reported by the beckhoff readout gauge has changed before and after the problems.  the normal vacuum guage does not see such a big change.  Also, it seems that Y5 was not working until we swapped the chassis today. 

Note for the operators:  There was no indication of this problem on the CDS overview screen.  You can watch for this problem by opening up an ALS PFD screen (for example, see screenshot) and checking that the RF MON and LO mon values are changing.  If they are not changing, you may need to call someone. Ed has this screen open for both end stations on he ops station. 

Mid-Shift Summary:

• IFO remains locked and Observing at ~70Mpc for ~ 2.75hrs. Earlier the Intent bit was turned off momentarily right after it was set and then turned back on because I noticed that one of the CAL lines wasn’t on. It was the EY PCal lines. The missing peak was a little hard to see due to the overlaying of plots. Seismic and wind activity remain quiet. MIcroseism has been steadily increasing over the last 22 hours. Occassional ETMY glitching (will be detailed in the end of shift activity log.

For our first lock after today's shenanigans, Betsy noticed that our only SDF Diffs were the PRM M2 coils.  We discovered that they get switched to the high range state occasionally, but not daily.  It turns out that in the PRC Align state of the interferometer we were setting the PRM M2 coils to state 2, however nowhere were they ever set back to the low noise state 3 for lock acquisition.  It seems that we had just been hand-setting the coils to the low noise state when we realized that they were wrong.

Anyhow, now in the ISC_DRMI's DOWN state, the PRM M2 coils are set to the low noise state 3.  The code has been loaded, so next time we do initial alignment the coils will be reset appropriately afterward.

Separately, I have made a "checklist" version of the Initial Alignment procedure on the Ops wiki page.  I was finding myself accidentally skipping steps (which contributed to the long day on Sunday) because the wiki page was too detailed for glancing through.  The checklist is available via the wiki page, and also attached here. 

IFO was temporarily swithced to "Corrective Maintenance" to turn on the Y PCal lines.

While investigating the 2 Hz comb in DARM, Sheila and Patrick found communications errors with beckhoff at EY. The End Station 2 Ethercat chasssis was brought back to the lab for further troubleshooting. Spare unit was installed and Beckhoff computer was restarted.

While troubling shooting the unit found a bad EK1100 coupler on the third rail (left) of the chassis. Re-scanned unit and found 5 terminals all EL3104 (anaolog inputs) that were giving us errors. After re-scanning/checking internal cabling/power cycling, we were only able to reproduce 3 errors. We tried multiply times to try and reproduce all five errors, but could not. Eventually after a power cycle, all errors we had previously seen could not be reproduce. 

After multiple re-scans and power cycles with no errors showing up, we used a voltage calibrator and injected a 5V DC signal into the EL3104 terminals. It was later decided to reinstall unit back at EY.

I was trying to use the fast ODC channels (e.g. H1:SUS-ETMY_ODC_CHANNEL_OUT_DQ) to track down ETMY saturation causes, but ran into a number of bugs in our data access tools that made it impossible:

1) dataviewer can play the trend data of integer ODC channels, but not the full data.

2) both dtt (diaggui) and lockloss (pydv) can't access integer ODC channels

3) using NDS2, the ODC channel is down-sampled to 256 Hz, making it useless for my purpose.
(why do we do that? That channel compresses either way, and takes the same amount of disk space)

4) dtt (diaggui) can access that channel, but only with the "now" setting, and

  IT RETURNS DATA WITH A TIME STAMP IN THE FUTURE!!!!

(The attached plot has a UTC clock in the terminal, and dtt's repored time stamp...)


sigh... I give up for today.

TITLE: Sep 15 EVE Shift 23:00-07:00UTC (16:00-00:00 PDT), all times posted in UTC

STATE Of H1: Locking

OUTGOING OPERATOR: Patrick/Jeff B

QUICK SUMMARY:Full control room, mostly working on last night’s 2Hz comb problem. Patrick is in H2 examining the EtherCat chassis from EY, responsible for Ring Heaters, for baddness. Lights are on in the LVEA. Wind is below 20mph. Seismic activity looks a little rumbly perhaps from a quake 7 hours ago and subsequent smaller ones in various areas. IFO is locked again for the first time in 7 hours. We are currently going to make some compensatory Ring Heater adjustments

Hugh, Sheila, Jenne, filling in for Patrick

We are filling in for Patrick at the moment because he is helping Fil to use the beckhoff test stand in the H2 building.  We are trying to lock now after Patrick and Jenne did a full initial alignment.  

This morning, Fil, Vern, Elli, Nutsinee and I swapped out the End Station 2 Beckhoff Chassis, because all the modules on the right rail were in the state INIT NO_COMM, and we could not change their state by requesting different states (including safe) or clearing errors.  We swapped the chassis with a spare.  Hugh and Patrick burt restored plc1,2,3 to 10 pm last night.  

When we first arrived we saw that the high voltage power supplies for the ESD were off, Fil turned them on and restored the settings.  This may be because the vacuum gauges which are controlled by beckhoff would have tripped them off. The ESD driver was off, but we did not reset it believing that we could reset it remotely. Later Betsy reset it by driving back to EY after she could not reset it in the normal way remotely.

Elli quickly noticed that something was amiss with the ring heaters at end Y, which are controlled by the same beckhoff chassis.  We checked that the settings were all the same, it seems like there is some difference between the 2 chassis.  

Fil, with help from several people, has spent most of the afternoon with the chassis we removed.  We had trouble getting a test set up going that we could use to diagnose the problem, so Hugh, Jenne, and I are relieving Patrick for a few hours so he and Fil can work together on the removed chassis.  They think that they have found a problem with one of the modules, and are currently replacing that module.  

We are about to reach low noise (with the spare chassis, and incorrect power on the ring heaters).  We hope to see that the comb is gone, and if we see that we may break the lock to revert to the old chassis if possible.  

Patrick's notes about his shift:

10 am PDT safety tour changed from X end to Y end(this may have broken our noisy lock this morning)

18:11 UTC placed beckhoff chassis at End Y

18:20 UTC Rick retrieves (?) PCAL out of optics lab

18:30 UTC Dick in optics lab out at 12:41 PDT

18:31 UTC Fil restarts beckhoff computer (Guardian to down)

a little while later h1ecaty1 burt restores to 22:10 Sep 14

18:53 UTC Jeff B, Jason retrieve part from optics lab (?)

12:38 PDT UPS truck at LSB

20:37 start of initial alignment finished at 21:22

20:54 Sheila to H2 electronics back 20:56, Fil is still there

20:58 Betsy to EY to restart ESD back 14:31

While the Beckhoff troubleshooting was going this morning, I ran a set of charge measurements on the unused ETMx SUS.  After completion a few hours ago, OPS/commiss started relocking attempts which are ongoing.

Results of charge measurements to be posted later.

With all of the Beckhoff attempted repair work this morning, the ETMy ESD "railed" with all 5 channels reading ~-15k.   I went down to EY and did the Push RED ON/OFF button, unplug far right DAQ cable, Push RED ON/OFF back ON button, replug DAQ cable in procedure.  This worked - the DC bias channel is back to ~-32k while the other 4 channels are near zero at ~-200 as viewed on the lower right of the ETMY SUS screen.

Andy, Laura, Dr. Dan Hoak

Something went wrong with the Pcal Y. It's not clear right now whether these were causing the glitches in ETMY, or whether there's a more general electrical failure at EY. The Beckhoff seems to have failed at 5:45 UTC (alog). At that time, we see the PCAL Y lines suddenly disappear, and this is obvious in DARM (first plot) as well as the PCAL Y photodiodes (plots 2 and 3). There are bursts of noise in the TX channel seen by the summary page spectrogram (plot 4), but shorter spectrograms of TX and RX don't show anything at times when we know DARM was glitching (plots 5 and 6). We'll continue to investigate.

16:45 UTC Sheila, Filiberto, Vern, Nutsinee to end Y to investigate problem with Beckhoff. Looks like some of the channels froze around 09/15 5:45 UTC. May be coincident with start of 2 Hz comb in spectrum.

Jeff, Darkhan, Sudarshan, Craig, Kiwamu,

We have updated the calibration filters in CAL-CS with the latest filters.

With a Pcal sweep measurement, we have confirmed that the current calibration is accurate within 10 % in magnitude and 5 deg in phase.

Calibration on the front end side is done.

(Verification measurement)

The above screen shot shows a measured transfer function from displacement estimated by Pcal Y to displacement estimated by CAL-CS. They agree within +/- 10 % in magnitude and +/- 5 deg in phase all across the frequency band we swept. Note that one data point at 10 Hz showed magnitude that is slightly above 10%, but this was not repeatable and therefore we don't think it is a reliable data point. We measured the same transfer function three times within the same lock stretch and saw the magnitude changing to a value between 0.85 and 1.1 at this particular frequency point. We are guessing that this is due to a bounce mode confusing our measurement.

Also, even though the coherence was high all across the frequency band, the data points below 30 Hz seemed to change in magnitude in every sweep. So we increased the integration time from 3 sec to 6 sec which seemed to improved the flatness.

The optical gain was adjusted by measuring the sensing function with a Pcal sweep within the same lock stretch. This gave me a 341 Hz cavity pole (which is the same as two nights ago, alog 21352) and an optical gain of 8.834e-7 meters/counts. Both the parameters are now loaded into the CALCS foton file and enabled.

(Phase correction)

Sudarshan will make a separate alog on this topic, but a trick to get this beautiful plot was to properly incorporate the know time delays. Based on our knowledge, we have included a 115 usec = (41 + 61 + 13 usec) time delay. If we did not remove the delay, the phase would have been off by 40 deg at 1 kHz.

(An extra measurement)

Independently of the calibration validation measurement, we did a simple measurement -- check the binary range with and without the calibration lines. Here is the relevant time stamps:

• Sep-11-2015 1:45:25 UTC, calibration lines turned off, not exctiations, fully locked at NOMINAL_LOSWNOISE
• Sep-11-2015 1:59:06 UTC, calibration lines turned back on.
• Sep-11-2015 2:50:03 UTC, unlocked

We will check the range later.