This is a follow up of 14209.

The trouble with the whitening was due to sub-standard quality of the DB37 connector shell of the binary IO cable.

The connector doesn't fully seat even if you tighten the connector screws, you need to physically press the shell hard towards the chassis to properly seat it. Once seated, the problem is gone until you give the cable one hard jiggling.

Once I removed the shell from one of the cables, it was easy to fully seat the connector and the whitening worked correctly even when I jiggled the cable multiple times. I removed the shell from all EY WFS BIO cables (but not from QPD BIO as they are working).

We have many of these connectors, but DB37 seems to be most problematic because the cable is very thick and gives the connector some good torque depending on how it's angled.

This type of DB37 connector shell has another problem, which is that the cable is so thick it's sometimes difficult to correctly put the shell halves together, as was documented by 12795.

At the very least, these shells need to be replaced with something more reliable. Or cables remade.

Gabriele, Peter, Dave

Restarted h1psliss with new model. Inputs and Outputs of the PSLISS common block connected to ADC/DAC at top level. After the model restart the DAQ was restarted.

J. Kissel, A. Pele, R. DeRosa

(c.f. LHO aLOG 14086)

After having spoken with the LLO team, Ryan informed me that he *did* in fact have to take considerable effort to re-arrange his sensor-correction STS2 readout system after initial install before he could use it. Regrettably, he hasn't written up any aLOGs or documentation on *how* his system is connected.

After a few more hours in the EE room, with new understanding of what was originally intended, and following cables through zipties and cable racks, I now understand that indeed the bulk of the problem is in the front-end models, AND that the HAM45 rack cables were just down-right disconnected at their AA chassis inputs for some reason. I've plugged them back in, and as suggested by Ben, in the order that the HAM16 wiring diagram (D1101584) suggests, such the DuoTone channels remain un-over-written, i.e. now ALL HAM ISIs and HAM HPIs have the following cable arrangment:
ADC_0_24   STS A X
ADC_0_25   STS A Y
ADC_0_26   STS A Z

ADC_1_24   STS B X
ADC_1_25   STS B Y
ADC_1_26   STS B Z

ADC_1_24   STS C X
ADC_1_25   STS C Y
ADC_1_26   STS C Z

As such, I don't think I need any more analog changes to the system, but it's time to dig into the top-levels of the front end models, now that I understand how the analog system is wired up. I attach a system drawing which I intend to follow, which is now a part of ECR E1400386, II 942, all cited in Work Permit 4876. I'll begin work as soon as I'm authorized, and Ben will begin updating the drawings accordingly.

Aleaxa, Kiwamu, Jenne, Sheila

• We turned on the ITMX oplev servo because we saw an oscialltion at 0.55 Hz by 2 urad pp (with sensor correction off)
• We need to install the 45 MHz amplifier to get reasonable signals for 3F.

We worked on DRMI tonight, it is locking at 1Watt within a few minutes. We are using gains of 22 for PRCL, 40 for MICH, and -400 for SRCL.  We are using the PSL-POWER_SCALE_OFFSET, so the gain settings and trigger settings in the gaurdian are now set for 1 Watt input power, but we could scale them to 10 Watts. We have been locking sometimes without the 27 Hz notches in M2 of PRM and SRM, and munually turning them on after it locks (this is needed to prevent the suspensions from ringing up).  We are using the guardian for everything else, including the offloading to M2. 

We started to measure the relative gains between 1F and 3F ( we think we need a gain of 3.2 in the input matrix to swtich PRCL to REFL 27 I) but quickly realized that we don' t have enough signal in REFL 135.  It seems like we need our 45 MHz amplifier installed before we can move on to 3 F. 

Times that DRMI was locked:

3:25 UTC october 1st - 4:21 UTC

5:10 UTC (maybe a few minutes earlier). This is still locked, Kiwamu is now scanning the OMC.

To do list:

• slow offloading to etms to help diff locking
• 3 f with amplifier
• as wfs

I started it back up with the previous channel list. It looks like it must be a problem with one of the channels that Dave tried to add. The error it logged was:

Sep 30 14:23:51 h1conlog2 conlog: ../conlog.cpp: 301: process_cac_messages: MySQL Exception: Error: Out of range value for column 'value' at row 1: Error code: 1264: SQLState: 22003: Exiting.

This would seem to imply that the value for one of the process variables was out of the range of the data type in the database. I'll try to narrow it down tomorrow.

See the linearity results attached.

The Range Of Motion results is unable to check (with the current script) H1-, V1+, & V4+ due to current offset on the IPS.  This needs to be reworked.

Maintenance Day Summary of CDS code Status:

Model code with local modifications with respect to SVN repository:

Alexa, Kiwamu, Jim, Dave

h1ecatx1 EPICS channels froze at 11:04PDT. The EPICS IOC was stil running, but all data was frozen and white-invalid. We restarted the computer and Alexa restarted the EPICS IOCs for SYS and PLC[1-3].

The ISS second loop photodiodes are very well coherent with the IMC WFS B yaw signal, as visible in the first plot.

This WFS is used for both DOF1 and DOF2 of the IMC alignment. I added an offset to the DOF1 yaw error signal. This improved significantly the intensity noise at almost all frequencies, see the second plot.

The thrid plot is a spectogram of the intensity noise as a function of time. The bottom trace shows the IMC DOF1 error signal. It is clear that a mean value of 250 counts gives lower intensity noise. It is also clear that intensity noise is highly non stationary, even with a good IMC offset.

The fourth plot shows the same story, but this time intensity noise is characterized with a trace showing the band-limited RMS between 100 and 200 Hz. Using the best IMC alignment offset reduces the noise in the band by a factor ~10. The last plot is a zoom into the last minuts of the test. It is clear that the residual fluctuations of intensity noise are related to the residual angular motion of the IMC.

In summary, we can improve a lot the intensity noise at the output of the IMC by choosing a better alignment position, and by improving the accuracy of the angular control loops.

NOTE:  Today there is a tour of the Hanford site for LIGO staff from around lunch time - 5pm.

Day's Activities

• Observation Bit was found in Commissioning state over night
• 8:02:  Bubba heading to EX to grab a vacuum
• ---:  Richard investing Beckhoff/slow controls error in the LVEA
• ~9:00:  Chris vacuuming at EX (it had been a while, dust counts will elevate, Commissioners:  is this OK during the day???)
• 8:43:  Danny heading out to work on Quad (Betsy will follow)
• 9:13:  Pulling Cables from HAM3 to Beer Garden (per Aux Power work permit) [Filiberto]
• ~9:45-955:  Drive to EY for ISC EY power cycle of IO Chassis [David Barker]
• 9:20-9:50:  BSC2 inspect HEPI inspection.  May take down the ISI/HEPI [Hugh Radkins]
• 10:00:  Peter K checking cables at HAM2
• 10:15:  Sheila slow controls work
• 10:23:  Unifirst
• 10:38:  Paradise
• CP Overfill Alarms at CP4 (signifying a Praxair delivery)
• Had the Slow Control Computer close at EX (seems to be a recurring thing on Tuesdays so far)

Leaving for Tour at 11:30 (Jim W & Dave will help cover the afternoon)

This morning I reset Counters for following HEPI systems:  HAM2, HAM3, HAM4, BSC3(itmx), & BSC3 (BS).

Note:  BSC3 & HAM3 continue to have saturations though.

WP 4869

The user environment has been changed to set up the awgstream environment properly.

The CERN ROOT package has been replaced with a version that supports python.

The gds software (diaggui, foton, etc) has been updated to gds-2.16.12.2, which has a number of bug fixes and a few enhancements:

* python scripting capability for awg and foton have been added.
* Cut/paste added to the Calibration dialog box in diaggui (and foton).
* Long channel names are no longer ignored in the Calibration dialog box.
* Fix bug preventing diaggui from reliably making continuous measurements.
* Unsigned 32 bit integer data support for diaggui time series.
* Foton legacy write option has been removed.
* Fix foton bugs for file path option, add "-o " option for non-gui file processing.
* Fix foton bug which caused crashes when invoked from diaggui.

Sudarshan, Jim and Dave

We power cycled h1iscey as part of the investigation to fix some dodgy ADC channels, we were not successful.

sequence:

take h1iscey out of dolphin, stop models, power down CPU, power down IOChassis, power down PEM AA chassis.

power up AA, power up IOChassis, power up CPU.

Sudarshan, Gabriele

To try to reduce as much as possible the beam pointing sensitivity of the ISS photodiodes, we wrote a python script that reads the PD signals and demodulate them with the excitation sent to IM3. In this way we could send a 12 Hz, 1000 cts sinusoid in yaw and a 17 Hz, 1000 counts sinusoid in pitch, and look at time domain traces of the demodulated signals, as shown in the first attached plot. We moved a bit the picomotors, and we could improve quite a lot the situation. As shown in the second plot, right now we almost can't see the sinusoids in the PD signals, since they're below the noise background. Here are therefore upper limtis on the dP/P/dx:

The optimal position we found is not exactly with the QPD centered (both x and y are around 0.3). Maybe we could improve this, but for the moment we guess the situation is good enough.

Summary:

Some whitening settings for EY green WFSA  I3, Q3 and WFSB Q2 channel don't work. It's probably the whitening chassis itself as the whitening request and the readback agree with each other.

For now I'm leaving both of the chassis in place as there are some usable settings, but note that these guys have a history of many troubles due to chassis and crappy cablings (12159,  12138, 12127).

Details 1:

For WFSA I3 and WFSB Q2, the measured whitening gain doesn't match the request and the readback (attached).

You can see that in both cases one of four stages (+3dB, +6dB, +12dB and +24dB) is failing. It's the 12dB gain stage for WFSA I3 and the 6dB stage for WFSB Q2.

These were measured injecting 20mVpp signal at 100Hz using a function generator and a breakout board.

Details 2:

For WFSA Q3, the third whitening filter doesn't turn on.

For now:

I set the gain to +27dB and turned all filters off.

QUAD 06 (Q6) Phase 1B transfer function plots are attached.   We had a hard time obtaining good coherence in the Transverse TF, so it is a bit hashy.  Will try again.  

Most notably is that, like Q8, the second pitch mode frequency is unexpectedly pushed upward on the main chain.  Recall, we never found the mechanism to fix it on Q8.  Interestingly, both the Q8 and Q6 assemblies are of the same batch of wires and are fresh builds, but by 2 different assembly teams, and on 2 different solid stack/test stand units.  Q8 is an ETM type of QUAD while Q6 is an ITM QUAD, but both main chains have the same pendulum parameters - both are detailed in the 'wireloop' model.

The Q6 data is plotted as QUADTST.