J. Kissel, M. Evans, D. Hoak, E. Hall, A. Staley

As Dan describes briefly in LHO aLOG 15297, we want to think about how to implement ALS COMM, ALS DIFF, DARM, and CARM, very-low-frequency, tidal offloading global control to the ETM HEPIs in the front end. Currently we're using a guardian-run servo over EPICs, as described in LHO aLOG 15244. In this log, I describe our thoughts on how to do for the long term.


After scouring the LSC model, we've found that ETM HEPI models are currently receiving the same LSC signals that the ETM QUADs are receiving. This is left over from when we were trying to attempt the distributed hierarchy. However, now that we've moved to an offloaded hierarchy for length control, we don't want to have to re-create the integrators that exist up the QUAD's signal chain, hope we get it right (and or the computer), and integrate once more to get the offloaded control signal we want. The REFL_SLOW path -- the digitized, slow output of the CARM Common Mode Board which takes the ALS COMM signal as its input -- was initially tossed up as an idea for the digital, very-low-frequency, COMM correction signal because it's currently hooked up through to the LSC CARM bank, but for the reasons described above, it's not exactly what we want for the long term.

After discussing the options, we've decided that we need an additional path from the LSC model to each ETM HEPI AND we want to restore the OFFLOAD path from the TOP of the QUAD (straight) to HEPI. 
Why?
- Currently, the digital IMC length control (the natural signal for controlling tidal drift) is only fed directly to MC2, and does not pass through the CARM or DARM banks.

- We don't want to offload to, or directly control use the TOP mass of the QUADs because that stage of the QUADs have proven to have particularly bad length-to-angle coupling such that large longitudinal control signals just pitch the test mass over destroying the lock just as much as tidal forces would by themselves by reaching the range of the various VCOs. 

- For CARM, one might ask - why not offload to MC2's HEPI? - can't because PR2 is also in HAM3, and the low frequency displacements to the PRCL aren't the same as what's needed for the red laser frequency. Further, a nuance of how the green end station lasers are tied to the PSL -- with the *transmission* of the reference cavity, which doesn't change when the IMC to PSL VCO to REFCAV REFL servo is changed -- while the COMM / CARM feedback to the PSL via the IMC changes the *red* frequency to match the common motion of the arms, it *doesn't* change the *green* arm laser frequencies in common with the arms.

- For DARM feedback, which will be sent through the suspensions because we need the bandwidth, will be offloaded on a few stages on its way up to HEPI. For CARM, we send most of the control through the MC2 SUS all the way to its TOP (because its a much better behaved SUS) and only the very low frequency would need to be send to the ends. So CARM and DARM need inherently different paths.

- For DARM, one might ask - why offload straight to HEPI, why not ST2 of the ISI and up-through as we've snaked through the QUAD? - because, currently, the best configuration is not to use ST2 of the ISIs. The offload path would require the isolation loops to be ON in order to function. Given that the ISI configuration is still, and will probably be, under flux, let's just go straight to HEPI which has happily run with position loops only for quite some time, and we've found that it runs best that way.

Given that we're still unsure what will work, we propose to create an additional, mini output matrix in the LSC model that takes in DARM, CARM, and IMCL, and spits out control to ETMX and ETMY HEPI.

How much extra infrastructure is needed?
- A new mini-matrix as described above, and the wires to make the connections from DARM, CARM, and IMCL to it and out to the top level.
- Two new RFM IPCs between the LSC model and the two end station HEPI models.
- Restore the M0 offload filter path and EUL2CART matrix that was removed in ECR E1300578, for the Longitudinal DOF only.
- Two new end-station dolphin IPC connections between the QUAD models and the HEPI models.
- Two new filter banks in the HEPI model (or at least after the output matrix, it could be in the LSC model) to match the frequency response of the direct CARM offloaded signal from LSC to the indirect DARM offloaded signals from SUS.
- A summing node at the top level of HEPI.

How painful will this change be? How much will it affect library parts?
- The LHO LSC model is currently still hooked up to a library, but I'm not sure whether LLO is using it. So, though not under ECR control, a discussion might be nice before a change is made. 
- Because we can only imagine doing such direct LSC global feedback to the ETM HEPIs, we can add the new filters and summing node to the top level of the ETM HEPI models, and send signals into the common HEPI library part as is without modifying it (or requiring an ECR). 
- Even though we've removed the OFFLOAD path from all SUS, because we had wanted to re-create the total length control signal on the QUADs eventually (like is done for IMC-X), the longitudinal control signals are still passed to the top of the library part for the QUADs (thank god). Thus, only a top-level change is needed for the QUADs as well -- the EUL2CART matrix and IPC parts can all be added to the top-level of the ETMs only. Because we're only trying to change longitudinal, we shouldn't even need the full EUL2CART matrix (as originally described in T1100617)
So in summary, not that bad.

BUT -- we'll probably still wait until next week to get started with the changes given the limited staffing over the Turkey-day holiday. 

Thoughts and comments welcome, ESPECIALLY those that come in BEFORE we make the changes.

Keita, Stefan

Yesterday we noticed that our alignment put the spot way low on the ETMY.

So today we tried to set the QPD offsets such that the TMSY well centres its green beam on ETMY. This allows us to use a co-aligned arm as good reference.

1) First we fine-tuned the PZT output matrix to well separate the POS and ANG DoF. We did that by dithering the desired DoF, and watching the camera shots in near and far field (ETMY scatter and TR_Y in the corner). Result:

H1:ALS-Y_OUTPIT_MTRX:
  POS    ANG
  1     -1.2   PZT1
 -0.12   1     PZT2

H1:ALS-Y_OUTYAW_MTRX:
  POS    ANG
  1     -1.25   PZT1
 -0.1    1      PZT2

2) Next we moved the POS DoF until we were happy with the ETMY camera image. We x-checked that by watching the green reflected powers (ITMY was misaligned). We used this to set the QPD offsets:
H1:ALS-Y_QPD_A_PIT_OFFSET 0
H1:ALS-Y_QPD_B_PIT_OFFSET 0
H1:ALS-Y_QPD_A_YAW_OFFSET 0.37
H1:ALS-Y_QPD_B_YAW_OFFSET-0.12

3) We then manually aligned the arm optics to this new beam position. We got an arm build-up of up to 1.09 (H1:ALS-Y_TR_A_LF_OUTPUT), about 10% more than before. Next we need to do the co-alignment.

4) A quick attempt to use the green WFS for that wasn't too successful.

5) We did a manual co-alignment of IR and green. We only got the green TR_Y to about 0.8, but that should be good enough for now. Kiwamu re-centered the DIFF beat note.

Attached are snapshots of the ITMY camera and all the alignment values.
Camera target values:
X-center 336.8
Y-center 238.5

There is now a new filter in the H1:SUS-ETMX_L2_OLDAMP_P filter bank which is supposed to help avoid exciting the bounce mode when the OpLevs are on (in FM3 called Phase9.8).

We had previously used this filter module (sending OL PIT to L2) as a means of damping the bounce mode excitation.  Now, we are hoping to prevent excitation by setting the phase of the usual OL filter to match that of the damping filter at the bonce mode frequency (roughly +90dg, see attached plot).

Finally got rid of the tired database and now have all the new useful channels.  Take a look at the new pump controller medm screen.  There are still a number of cables to run but all the ports available are at least in use now and database junk has been discarded.  We still need to modify the board to power the amplifier for the remote pressure sensors at BSC2; we'll try to knock that out next week.

Attached is a shot of the new controller screen.

06:30 Cris into LVEA

08:00 LVEA is LASER HAZARD

08:00 OIB set to "Commissioning"

08:01 restarted Alarm Handlers

08:02 Restarted DTT session on projector 1

08:03 Restarted "hung-up" Operator2 workstation

08:25 port-o-potties on site for exchange

08:30 Corey out to LVEA

08:35 ISS diffracted power adjusted to ~7.6%

08:39 Aaron to EY for PEM work

08:40 HEPI HAM4 L4C watchdog accumulator reset - sat count 380

08:43 Keita and Daniel to EX

09:00 I'm running PSL DBB reports

09:06 Cris to EX

09:19 Travis into LVEA

09:25 Hugh to mazzanine to put HEPI pumpd in manual control. He'll be staying there and adjustin them manually

09:31 Karen into LVEA

09:45 Kyle into LVEA

09:52 Tour group into control room

10:37 Cris back

10:55 Karen to EX

11:04 Dave restarted FSS, ISS and PMC models to accomodate change in acq rate.

11:04 Dave restarted DAQ

 11:13 Water delivery

11:34 Sudarshan into LVEA

12:02 Karen leaving EY

12:06 Corey out of LVEA

12:11 Sigg and company back from EX

15:20 Gerardo into H2 LASER enclosure

Hanford hauling indicates that they will not be running trucks on day shift or swing shift on Weds, Thurs or Fri of this week, nor over the weekend. 

The button is intermittent because h1lsc is running at RCG2.8.3. The fix for this will be implemented when we upgrade to RCG2.9. In the meantime scripts should check if the button press was accepted, and try again if not.

Sudarsan, Peter, Dave: PSL model changes

The h1psliss, h1pslfss and h1pslpmc models were modified to downsample all 32kHz channels to 16kHz. This resulted in 10 32kHz channels changing to 16kHz with the distribution: ISS=1, FSS=4, PMC=5. The models were restarted and the DAQ was restarted. This resulted in a science frame size reduction of about 20MB per 64 second science frame (2%). The restarted models were burt restored to 9am PST today.

Dave: DMT broadcaster

Following last week's ISS model change, the H1BROADCAST0.ini file was changed to replace the obsolete H1:PSL-ISS_PD[A,B]_OUT_DQ with the calibrated H1:PSL-ISS_PD[A,B]_REL_OUT_DQ. Also the obsolete H1:LSC-OMC_DC_OUT_DQ was removed from the DMT.

Hugh, Dave: HEPI pump controller channels

Following Hugh's software change on the corner station HEPI pump controller EPICS system, a new EDCU INI file was added to the DAQ. Hugh has updated the MEDM screens and is updating the autoBurt.req file.

Dave: Restart of H1SLOW-F1FE EPICS gateway

Following the restart of h1ecatx1 this morning, subsequent restarts of the DAQ EDCU did not establish new connections to this IOC. I restarted the EPICS gateway between the EDCU and the Beckhoff IOCs which prompted the EDCU to re-establish a connection. It took several minutes for the reconnection to complete. Initially the number of disconnected channels went from 1,951 to 81, then took a further minute to reduce to zero.

Dave: DAQ restarts

To support the above work the DAQ was restarted three times this morning. On restart 1 and 3 the data concentrator was very slow on restarting (several minutes) while restart 2 proceded at the usual pace. While waiting for the slow restarts I had time to check for duplicate channels (none) and any errors in log files (none).

Jim, Dave: replace broken thunderbolt monitor at operator station

I collected the repaired Apple thunderbolt monitor from Alpha Computers this morning, Jim installed it at the operator station. We are looking into a tether cable solution for strain relief.

Daniel, Keita, Elli

This morning we worked on the ALS at Ex:

-We added autoalignment PZTs to the green WFS path.  Mirrors ALS-M16 and ALS-M19 were taken out and and relaced with PZT mirrors.  After adding the PZTs we realigned the green beam back onto the WFS.

-We removed two mirrors blocking the beam path upstream of ALS-M19.  The mirrors weren't on the table layout and didn't appear to be doing anything.

-Swapped feedthorugh panels D1100434 on ISCTEX with replacement panels.  The original panels had the wrong size screw spacing.

[Stuart A, Arnaud P]

Damped TFs had been taken on MC2 back in August (see LHO aLOG entry 13346), but had not been processed until now:-

- MC2 M1-M1 undamped TFs (2014-08-11_1091848686_H1SUSMC2_M1_damp_ON_ALL_TFs.pdf)

Before the corner vent, MC2 had been exhibiting 1 Hz Pitch and 1.5 Hz Roll modes cross-coupling into the Vertical DOF, which had been exacerbated when the chamber had been pumped down to vacuum (see LHO aLOG entry 11383). This was suspected due to EQ stops being set too close and rubbing, which is captured in an Integration Issue #847.

After the most recent July corner station chamber incursion, transfer functions taken at Phase 3a (in-air) for MC2 showed no cross-couplings into the Vertical DOF (see LHO aLOG entry 13036). Having now pumped down, the damped Phase 3b (in-vacuum) MC2 M1-M1 TFs presented above, are clear of cross-couplings into the Vertical DOF.

Below is a comparison of undamped Phase 3 MC2 TFs (see allhstss_2014-11-24_Phase3_H1MC2_M1_Doff_ALL_ZOOMED_TFs.pdf), the plot keys are as follows:-

Blue Trace = Model (hstsopt_metal)
Orange Trace = H1 MC2 M1 (2013−05−25_1053525085), Phase 3b
Magenta Trace = H1 MC2 M1 (2014−07−28_1090619695), Phase 3a

The original MC2 cross-couplings into Vertical DOF were present in Phase 3a and then exacerbated going to Phase 3b. However, the recent in-air measurements show absolutely no seeds of a cross-coupling.

Below is a comparison of damped Phase 3 MC2 TFs (see allhstss_2014-11-24_Phase3_H1MC2_M1_Don_ALL_ZOOMED_TFs.pdf), the plot keys are as follows:-

Blue Trace = Model (hstsopt_metal)
Orange Trace = H1 MC2 M1 (2013−05−25_1053543407), Phase 3b
Magenta Trace = H1 MC2 M1 (2014−08−11_1091848686), Phase 3b

Furthermore, back in April, even the damped in-vacuum TFs showed the aforementioned cross-couplings into the Vertical DOF. However, this is again not visible in the recent damped MC2 TFs.

Summary:

The above measurements indicated that there is no longer any pitch or roll cross-coupling in the vertical DOF of MC2 and therefore, that after the July corner station chamber incursion that the suspension is clear of EQ stops rubbing.

This should prove sufficient to close the Integration Issue #847.

All data, scripts and plots have been committed to the sus svn as of this entry.

PSL laser weekly trends.

Aaron and I continued with PEM cabling at EY this morning. We have completed all long cables runs and started installing the permanent power supplies in the DC rack. We disconnected the power supplies powering the microphones in both the VEA and EBAY and placed them in the DC rack. Got a call from commissioners asking us to leave EY, before we could reconnect microphone power with permanent power supplies. Will go back tomorrow morning and power them up. 

Matt, Dan

After Alexa gave us a quick alignment tutorial, we started by fiddling with the dither alignment of the X-arm.  The PD thresholds for dithering across the baffle PDs were set to very small values, so small that the dither would declare victory before it even started.  Matt has been working on the initial alignment, I'll let him say more about it.

We noticed that the green spot on the TMS-Y mirror, visible through ETMY, is very low.  There are large offsets in the EY green QPDs that steer the beam to what looks like a bad place on the mirror.  Zeroing these offsets (which is where they were for most of the last six months) would have forced us to begin a painful realignment procedure, so we left them as we found them.  Historically it looks like people have set these values to maximize the buildup in the arms, but it's hard to believe that the optimal beam position is so far off-center.

With the arms well-aligned for green we aligned the corner optics - IM4, PR2, PRM, BS, SRM.  The scripts for this went quickly, about five minutes.

Then we locked the DRMI, with the arms misaligned.  Locking tonight was fast and robust; the DRMI would lock within a few minutes (rarely more than 5 minutes), and would remain locked for tens of minutes.  There were many unexplained lock losses, so things are not as stable as we'd like, but we didn't see any mode hopping and the sideband buildup was consistently good.  Over three hours of DRMI locking we didn't observe a significant drift in the alignment.

We went through the DRMI guardian and commented out lots of gain/switch settings that weren't needed, mostly for the DC centering.  The script is now pretty fast, it goes from lock acquisition to ASC loops on in less than 30 seconds.  We did not observe any unexpected long pauses.  The duration of the script is dominated by ramping the SRM and PRM M2 gains, this takes 9 seconds total (4.5sec each).

We re-enabled the PRM and SRM2 offloading to M2.  We found the SRM offloading was a little flaky and sometimes broke the lock.  To make this a little gentler, we reduced the initial gain ramp to 1, and ramped the rest of the way (to 4.5) after the WFS turned on.

We measured the LSC OLTFs and found that MICH and PRCL didn't have much phase margin (~25deg each).  We reduced the gain for these loops so that they both have >30deg.  The MICH gain is now 3 (was 5) and PRCL is 15 (was 22).

Afterwards I mucked around with the OMC, I found a set of good misaligned values for ITMX and ITMY that minimized the RIN at the dark port when the other ITM was aligned (presumably this steers ghost beams away from the OMC).  Following Gabriele's instructions I used the picos to center the beam on IMC WFS A and added some offsets to the IMC ASC loops; this reduced the intensity noise measured by the ISS second loops PDs by a factor of three or so.  I tried to engage the ISS second loop but failed.  The script posted here did not appear to work; I tried to follow these directions but the loop was unstable.

Plots attached are MICH, PRCL, SRCL loops before we reduced the gain to get some phase back in MICH and PRCL.

J. Kissel, J. Warner, E. Merilh, H. Radkins

While taking down and bringing up the HAM2, HAM5, BS, and TM ISI + HPIs this morning to upgrade suspension front-end code (see LHO aLOG 14830), we had the following troubles with platforms:

(1) The Rogue Excitation Monitor for HAM5 ISI could not be naively reset, and was caught in a trip-loop.
     - First of all, it's frustrating that there in no MEDM screen indication that the MASTERSWITCH must be ON in order to reset the rogue excitation monitor, so myself / Jim / Ed spent a few minutes clicking all the watchdog reset buttons hoping that there was some special order, until Hugh informed (reminded?) us that the master switch needed to be on
     - Second, I'm not 100% confident why, but after enacting the "correct order" of reset by turning on MASTERSWITCH, reset Rogue WD, reset all to untrip the DACKILL, the MASTERSWITCH would turn itself OFF again before the three-second counter/delay of the rogue excitation was finished, therefore re-tripping thinking the MASTERSWITCH never was turned ON. I'm 90% confident this happened because the MASTERSWITCH would "turn itself off" because the SEI manager demanded that the MASTERSWITCH be OFF because it was still in the OFFLINE state.
     Why do we have the SEI Manager controlling the MASTERSWITCH, but the ISI module controlling everything else?

(2) There are no monitor signals on the MEDM overview screen to indicate what is currently causing the Rogue Excitation Watchdog to fire. This proved solving the above problem initially difficult -- I had to open the model to find out the logic (especially the hard-coded "100 [ct]" threshold), the three-second delay, open the CDMON channels in dataviewer, find they were low, and then go for figuring out the MASTERSWITCH trick. We should (a) added epics monitors on the three *inputs* rogue excitation monitor, and (b) create a sub-screen for the rogue excitation that reveals the details of this monitor.

(3) The BSC-ISI overview screens have the SEI Manager guardians on the overview screen. The BSC-HPI overview has the HPI module guardian. The HAM-ISIs and HAM-HPIs have their individual module guardians on the overview screen. This resulted confusion when trying to quickly bring the platforms back from offline -- I'd gone to the HAM-ISI overview after just finishing the BSCs, and out-of-habit assumed the guardian drop-down menu was the manager and was surprised why it wasn't doing anything for me. Arnaud informs me that this is because the overview screen mods were first made at LLO, where they're not using HEPI and therefore don't need a manager. Since not-using-HEPI is a deviation from aLIGO baseline, I argue that we should fix this by creating the SEI manager for the HAMs, and just temporarily create a managed configuration that doesn't use HEPI -- instead of having the confusing user interface for the HAMs.

(4) The SEI manager for ITMY seems to *not* automatically turn on the MASTERSWITCH. Is this automatic operation consistent between chambers? Between HAM managers and BSC managers?

(5) HAM3-HPI's L4C saturation counter in watchdog wouldn't reset with a RESET ALL or RESET above the current trigger but, but RESET WD ONLY worked. We can confirm that every other chamber behaves as expected, i.e. any of the three methods reset the counter. What's different about HAM3? Is this reset a python script that is uniquely defined per chamber or something?

A set of scripts was created last week to allow commissioners to switch SEI platforms to SEI’s preferred testing configuration at the end of their shift.

The scripts are very simple for now: 

• They switch the sensor correction on/off using the ezca python library.
• They switch blend filters using the standard SEI Perl script (with smooth ramp)

Those new scripts were put in the svn so they can be remotely adjusted, and improved (made more generic, make classes/methods, etc…):
/ligo/svncommon/SeiSVN/seismic/BSC-ISI/H1/Common/Misc/Test_Configuration_Scripts/

• Switch_To_Test.py 
• Switch_To_Comm.py

To run those scripts:
$ cd /ligo/svncommon/SeiSVN/
$ python Switch_To_Test.py (at the end of the commissioning shift)
$ python Switch_To_Comm.py (when commissioning resumes)

Kiwamu used those scripts at the end of his shift on 10/28/14. JimW and I added the senscor switching capability on 10/29/14, which does not change the way to run the scripts.