11:38UTC Glitched down to 36Mpc. It doen't appear to be related to the typical ETMY saturation. Should have kept quiet about it!

The ODCMASTER in SDF will show 1 diff during this segment due to a change that had to be made that was blocking the Observation Ready bit to Green and keeping he INtent bit from being set. CALCS will also show diffs during this segment. Commissioners aren't certain what these mean.

Tagging DetChar so they're aware of this entry.

The various noise features that appeared after maintenance today -- the 1Hz comb below 70Hz, some broadband noise above 80Hz, and the peaks around 850Hz -- are all coherent with the DRMI length error signals, and are much louder (compared to quiet references) in PRCL and MICH.  Something is different in the corner station...hopefully all three things have the same source.

The 1-Hz comb with 0.5-Hz offset is prevalent in magnetometer channels.
Looking at a typical magnetometer FSscan spectrogram is not for the faint
of heart, but there are plenty of examples to be found here.

One example from EY_MAG_EBAY_SUSRACK_Y is attached. It's not unusual.

Since the reports stated it shows up in PEM channels I disconnected the LO to the antenna Demod board that resides in the PEM rack and was coincidentally connected yesterday and the comb disappeared.  WE need to verify the RF level needed for these radio signals.  Pick some attenuators and re-installed the LO signal.  I put terminators back on the outputs from the distribution chassis.

This could also have been due to a ground loop. A balun should be added to the lines.

I thought this might be the ITM HWS. It looks like the filter on the power supply (which is filter out the 1Hz comb) was turned off yesterday.

A small point about the PRM/PR2 experiment: when we switched to PR2, there was a huge 45 Hz resonance (visible in DARM and the vertex LSC signals) that was rung up. It was distinct from the usual 41 Hz HSTS roll mode resonance that we usually see when passing through the noise tuning step in full lock. It did not ring down on its own.

We made sure that the PRCL OLTF did not change before and after the swap, and anyway the loop appeared to have enough phase (more than 30°) at this frequency, so I don't think it was gain peaking. By increasing the loop gain, we were able to bring the resonance down a little bit. I then added 4 dB of resonant gain around 45 Hz, which somehow squashed the resonance completely. (I put it in the PR2 M3 lock L SFM).

It's not clear to me what was going on here.

It looks like the injection actually does hit the 400 count limit (plot 1). It saturates right at the end when the injection chirps up to high frequency. There's some kind of ringing as well (plot 2). From the spectrogram (plot 3) and the zoom (plot 4) this looks like a feature at just above 300 Hz. I thought it might be a notch for the PCal line, but that's 331.9 Hz. So someone will have to check the inverse actuation filter and see what's happening at that frequency.

It's possible to see the overflow from the first injection in the ETMY L3 MASTER channel (plot 5). It happens at -131072 counts, and the injection is trying to push it past -200000. The blind injection caused an overflow as well, but since this channel is only recorded at 2048 Hz, it looks like it falls short of overflow (plot 6). There's a faster readback whose name escapes me at the moment.

Unless the blind injection is made a factor of about 10 smaller, or rolled off at high frequency, it will be trivial to detect it by looking at the drive to the ETM.

FYI, the injected waveform was fiducial waveform from ER7:

https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=16125

It's a 1.4-1.4 BNS at 45 Mpc, optimal orientation.

There are a couple of things to watch out for when performing CBC hardware injections, based on iLIGO experience:

• In iLIGO, the actuation function had a notch at the violin-mode frequencies. If you just invert A(f) without smoothing this out, the notch will get inverted and you'll give the the mirrors a hard kick as the inspiral sweeps through the notch frequency. (My guess is that Adam and Jeff have already dealt with this, though.)
•  If the end of the inspiral signal is not smoothly rolled off and the signal drops from some loudish amplitude to zero then you put a step function in. This caused the iLIGO test mass to swing at its pendulum frequency, putting a huge ringdown in the data (called the "whooper" in iLIGO). In iLIGO, the CBC group generated waveforms in counts, by applying 1/A(f) ourselves using the adiabatic inverse calibration, so we smoothed 1/A(f) ourselves before applying it. In aLIGO, 1/A(f) is: (i) more complicated, and (ii) applied in the front end by IIR filters. It is possible that the sharp turnoff of the CBC injection at the end is causing the filters that apply 1/A(f) to ring and that's what's giving us garbage at the end of the signal.

For the ER7 injection we used an SEOBNRv2 waveform that has a ringdown at the end, hoping that this turn off would not trigger an impulse. However, for BNS masses, the turn off and ringdown is pretty sharp. I've asked Chris check that there are no "whooper" effects with the SEOBNRv2 waveform, but we haven't had chance to do this yet. For a SpinTaylorT4 waveform (the other waveform CBC wants to inject), there will definitely be a step, so this needs to be checked and rolled off carefully.

One other comment on the test: what scaling in awgstream did you use? That waveform looks monstously loud (eyeball SNR > 20). That's much louder than would be useful for a blind injections, but good for helping us find whooper effects.

Duncan, the scale factor is 1.

Just for completeness, because I didn't see it posted, here's an Omega scan of the injections in h(t). The first is the non-blind injection, the second is the blind injection. I think the glitch ten seconds after the blind injection is unrelated. I thought it might be a filter turning off or being reset, but it's not on a GPS second (it's at 1124603210.28). It does cause an overflow of the ETMY ESD DAC.

I verified that the blind injection was correctly recorded in the raw frame file.

Evan deciphered the ODC screen that was apparently telling us that TCS was not observation ready.  We put a 0 in the   H1:ODC-MASTER_TCS_2_MASK, and this made the observation bit ready, so Ed has set the intent bit.  

I think this has uncovered a bug/issue:  There may be a problem with the connection between the TCS ODC and the ODC-MASTER models at LHO.  I'm debugging it now and will reply with what needs to be fixed.  

On a separate note:  I believe site leads (at least Fred) said that operators would be trained on how to read and use the ODC with the changes made in https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=20870 and Duncan M. and Stefan B. are the experts on site to teach people how to read this screen, but I'll walk through the way to read it for this example:

Evan correctly read off the bit that was preventing obs-ready from being green from the ODC MASTER overview screen.  To do this, you just trace across the row that you care about (OBS-READY) and find the red bit, then count across the top list of subsystems to find which subsystem that is coming from (I would appreciate it if anyone can show us how to turn those text boxes so we can align them with the columns better).  The next step would be to look down one step further by clicking on the TCS button to see that the 30th bit of the TCS ODC is the only bit that can affect the OBS-READY bit.  From the comment, this was done correctly as well, and you can read off the bitmask for the relevant row in the matrix on the right.   You can also see this by looking at the large black/green matrix to find the green bits that affect each row, which tell you which bits of the subsystem ODC are mapped to which row in ODC MASTER.  At this point, you will see that the whole TCS ODC at the top of that screen is red, however, which I believe is a bug somewhere in the FE code.  If it were behaving normally and you wanted to learn what the bits meant in the vector at the top:  The last step would be to click on the relevant subsystem from the ODC-SITE-OVERVIEW screen, and in this case you would learn that bit 30 is the Excitation bit, as expected.   

I have found the issue:  The h1odcmaster.mdl was locally edited and then committed to SVN on Aug. 18, as recorded in alog:  https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=20622

This occured after we had circulated the new h1odcmaster.mdl that was used for alog: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=20870.

Duncan M. is going to ensure that everything is up to date with the SVN, then re-implement the changes he made on Aug. 18 in a copy of h1odcmaster.mdl and then generate the ECR to fix the bug.

For the time being, I have set all the bitmasks of form H1:ODC-MASTER_TCS_XX_MASK to 0x0 so the bad connection cannot affect ODC-MASTER.

Ryan, this does not adequately explain the situation. Why does the bit mask in TCS affect READY? We were told that READY was just GRD-IFO_OK and NO EXC. How was it that TCS was somehow wired into that logic?

Unit removed S1100045.
Unit installed S1100025.

What is the MEDM Overview Screen?  Is this the overall QUAD Overview?  If so, where is the new(ish) warning message?  Are you talking about the Guardian message window (upper right corner) on the QUAD overview?

On the top-level screen for each quad, you should see a red rectangle appear around the top, UIM, or PUM coil output filters that says "rocker switch death", as in this screenshot from Jeff's alog.