Yesterday at 13:40 and at 22:40 PDT the CW stopped exciting the EX PCAL because its testpoint was cleared from awgtpman. The excitation slot in the awg remained even though the excitation was not active, so the CW sender (psinject process on h1hwinj1) was unaware that its excitation was no longer operational and did not try to restart. When this happened the CDS overview screen did show a red excitation error for h1calex (meaning that an excitation should be present but is missing) and the operator medm overview should have shown a missing CW error as well.

The problem was found to be a "feature" in diag which allows the user to clear every test point on every model with one command. The feature was accidentally acitvated yesterday when the dcu-id and the testpoint were interchanged in the tp clear command.

Jim is working on removing this feature from the current diag code to prevent this accidentally happening again during ER9.

The reason why the IFO second loop didn't like the ISS 2nd loop is because the ISS 2nd loop offset is now hard coded (28076) while the power and diffraction both changed because of the diode swap and subsequent tune-up.

I remeasured it at 40W (H1:PSL-ISS_SECONDLOOP_REF_SIGNAL_ANA=-0.027689945 for 16-17% diffraction) but Vern told me that it was decided that we'll run IFO at 25W during ER9, so I measured it yet again at 25W (-0.027651985).

I'm puzzled that the number changed this much (previously it was -0.9826934814453125 at 40W).

It's also odd that there's not much difference between 40W and 25W. The diodes are definitely connected, the readback of analog sum (H1:PSL-ISS_SECONDLOOP_PD_14_SUM_OUT) is almost 100% coherent with the digital sum of individual PDs (H1:PSL-ISS_SECONDLOOP_SUM14_AC_OUT and H1:PSL-ISS_SECONDLOOP_SUM58_AC_OUTPUT).

Anyway IMC_LOCK guardian was modified for 25W (H1:PSL-ISS_SECONDLOOP_REF_SIGNAL_ANA, iss_diffracted_power_target=16.5).

Update:  I was likely tricked by MEDM screen (graphics of switch states sometimes don't agree with reality) when I was doing the above measurement with only MC locked.

With full IFO the above offset was found totally off, and at 25W H1:PSL-ISS_SECONDLOOP_REF_SIGNAL_ANA=-0.5885 or so for 15%-ish diffraction. Didn't have time to remeasure at 40W.

We were showing Dan the h1fw0 problems (after turning on all frame writing again) and after less than an hour h1fw0 became stable again and has been running for 2+ hours. We will leave it in this state for now, but if it becomes very unstable again we have several options:

Turn off LDAS frame comparison jobs (reads every frame on both writers)

Remove all LDAS archiving from h1fw0 over to h1fw1

Reduce h1fw0 back to only writing science frames

Fingers crossed we don't have to do any of these.

Dan confirmed how the frame files written by CDS are currently accessed by LDAS for archival and checking, summarized below.

h1fw0 writes to the ldas-h1-frames file system (located on SATABOYs in the warehouse)

h1fw1 writes to the cds-h1-frames file system (located on SATABOYs in the MSR)

h1fw0/ldas-h1-frames

science frames are copied over to LDAS every 64 secconds

science frames are read every 64 seconds to compare them with h1fw1's frame

commissioning frames are read every 64 seconds to compare them with h1fw1's frame

second trend files are copied over to LDAS archive area every 10 minutes

second trend files are read every 10 minutes to compare them with h1fw1's frame

minute trend files are copied over to LDAS archive area every 10 minutes

minute trend files are read every 10 minutes to compare them with h1fw1's frame

Started and ran the purge-air skid, Turbo, QDP80 and newly added scroll pump.  Tested the functionality of the Turbo's Safety Valve with the control cable connected to the scroll pump's relay box - demonstrating that the Safety Valve closes upon the loss of scroll pump motor AC and thus mimicking the "QDP80 Running" 
signal.

Note: The purge-air skid has developed some problems from lack of use over these past few years, namely the radiator fan never came on while running the compressors, the drying tower never cycled and the low pressure alarm never sounded.  These features worked fine when last this unit was run.  Now they don't.  Also, the Turbo spun-up normally even with the locally mounted scroll pump running (new vibration source) but tripped into EMERGENCY OPERATION upon BRAKING and when at ~1/3 NORMAL rpm.  This behavior is seen on other Turbos (XBM for example) and might be an age related issue?  

I am leaving the Turbo energized overnight to ensure that the rotor is completely stopped.  I will de-energize it tomorrow.  

State of H1: locked at 25W, but no ISS 2nd loop

Activities:

• Peter King - PSL - FSS tuning
• Kyle - MX - vacuume work
• Robert - electronics room
• JimW - HAM2 blend filter update

Glitches:

• PSL AC left on - now off
• Confusion over a guardian state - lock loss
• ISS 2nd loop is not working - currently being worked on

Special Instructions:

• SRM human servo - found on ASC medm tab, SRM POP90 - use to keep the signal low and smooth (offsets in guardian were for 40W, but Sheila fixed by taking them out)

Files ending with .001 are Lo Power; files ending with .002 are HI power (with the exception of the msc file .003)

DBB: all scans look as good as can be expected given the recent tribulations in PSL land. Higher order modes (TEM 01, 02 & 20) are a bit high in the HI power.

ISS_RPN: AOM diffracted power running higher than usaual these days. No surprise there that's it's much higher than reference. PDB is the Diode du jour and it's running above reference as well to the tune of 1 order of magnitude at 10Hz and 2 OOM at lower freq.

For better in-depth analysis, please refer to the experts; Peter K. and Jason O.

Due to the inability so far to damp the 18040Hz mode I have switch the PI damping to the DCPD HF path.

I changed up a few things such as:

• Catches TypeErrors caused by model restarts. I am nervous that this may catch more than I want, so I also added...
• Any error will email me with details. Often times I never even find out that there was a problem until it becomes a bigger one.
• Minor modifications to a few tests .
• Added a test for the PSL AC.
• Changed the way it gets a Guardian node list. I used to have it call "guardctrl nodes" but this would not work on the alarm computer due to different versions of Bash, plus it is just a really clunky way getting that list. Now it just calls a function from the guardctrl client code to get the list directly.

If there is any problem with this version, please don't hesitate to go back one revision.

Attached are plots of the transfer functions measured this morning.  The input modecleaner
was disabled whilst these measurements were obtained.

    Note the frequency servo schematic is D040105

C20F22-1.tif: common gain = 20 dB, fast gain = 22 dB
C20F16-1.tif: common gain = 20 dB, fast gain = 16 dB

C20F22FastMon.jpg: transfer function measured at TP10
C20F22PCMon.jpg: transfer function measured at TP9
C20F22TP8.jpg: transfer function measured at TP8 (should be 10X greater than TP9 measurement)
               common gain = 20 dB, fast gain = 22 dB

C16F22TP8.jpg: transfer function measured at TP8, common gain = 20 dB, fast gain = 22 dB
C16F22TP9.jpg: transfer function measured at TP9, common gain = 20 dB, fast gain = 22 dB

C20F16TP9.jpg: transfer function measured at TP9, common gain = 20 dB, fast gain = 16 dB
C20F16TP8.jpg: transfer function measured at TP8, common gain = 20 dB, fast gain = 16 dB

C20F16TP3Spectrum.jpg: noise measured at TP3 (the mixer monitor, or error point)
                       common gain = 20 dB, fast gain = 16 dB
C20F22TP3Spectrum.jpg: noise measured at TP3, common gain = 20 dB, fast gain = 22 dB

CrossoverSpectrum.jpg: has the two noise spectra overlapped for a visual comparison.

Peter was in the PSL enclosure and looking at the FSS - his alog will give details.

He's done so I'm starting to lock.

[Everyone]

We have determined (a few hours ago) that flipping the ESD bias sign on ETMX does not allow us to lock ALS DIFF.  Jeff has looked through the settings, and everything is flipped to match the bias sign as appropriate, but we're still not able to lock.  It looks like a crossover is unstable, or something like that.  For now, we have reverted the ETMX ESD bias to its pre-Tuesday state, which has facilitated locking.  Team SUS will look into this later.

The ISS is much better behaved now that the alignment work was done.  However the FSS gain change was making the IMC loop very nearly unstable, and we lost lock during the power-up twice due to this instability.  Sheila and Keita will post their measurements that discovered and fixed this issue.

We have so far been able to power up to 40W once, but it looks like a PI rang up pretty quickly.  Carl will post details, but this is a new mode that hasn't been a problem previously, so it does not yet have damping settings.

At this time, it looks like there is no problem in getting to 40W, and other than PI damping we should be able to get all the way to low noise.

If Carl is unable to find damping settings relatively quickly, we may choose to instead only go to 20W for tonight, so that we can get to low noise and set the intent bit.  Stay tuned for more updates...