Maintenance Day Log:
Locking is now in progress, Bounce/roll modes are high and are being damping at the moment.
Richard, Filiberto, Ed, Betsy
Following on from Andy's probing alog 27841 regarding funny looking OSEM spectra, today we looked into a few fishy signals. Based on spectra he took from before and after the early June power outage which show signal changes, he and Jenne identified the following set of problematic OSEM signals. I've annotated the list with status as to what we found or fixed today:
ITMY L2 LR - Fixed after power cycling the Satallite Amp box (see alog below)
ITMY R0 RT - Signal looks funny before power outage, old problem, TBC...
MC1 M3 UL - Signal looks funny before power outage, old problem, TBC...
PRM M2 UR - Fixed after power cycling the Satallite Amp box (see alog below)
PR2 M1 T2 - TBC...
PR2 M3 UL - Giant nominal YAW Bias which has been on this SUS for over a year - very little signal on OSEM - mechanical fix when vent
PR2 M3 LL - Giant nominal YAW Bias which has been on this SUS for over a year - very little signal on OSEM - mechanical fix when vent
SR2 M1 LF - Funny comb feature, TBC...
SR2 M1 T1 - Funny comb feature, TBC...
SR2 M1 T3 - Funny comb feature, TBC...
ETMX L2 LL - 50Hz turn up noise, TBC... Turn up is due to LOCK ACQ PUSHING, turn up not present during nominal SUS damping, no LOCK ACQ, see below plot
ETMX L2 LR - 50Hz turn up noise, TBC... Turn up is due to LOCK ACQ PUSHING, turn up not present during nominal SUS damping, no LOCK ACQ, see below plot
ETMX L2 UR - 50Hz turn up noise, TBC... Turn up is due to LOCK ACQ PUSHING, turn up not present during nominal SUS damping, no LOCK ACQ, see below plot
ETMY L2 UR - 50Hz turn up noise, TBC... Turn up is due to LOCK ACQ PUSHING, turn up not present during nominal SUS damping, no LOCK ACQ, see below plot
IM3 M1 LL - TBC...
We plan to pursue ITMy R0 and SR2 this week at next opportunity.
J. Kissel After measuring charge today, I've flipped the BIAS sign on both ETMX and ETMY. In addition, I've changed the compensation scheme downstream of the BIAS flip such that signs are flipped in each quadrant's ESDOUTF bank GAIN instead of being convoluted in the the DRIVEALIGN matrix elements. This separates the functionality, compensates any angular control as well as longitudinal (though we don't send any angular control to the test mass stage at the moment), and minimizes the possibility for losing the fine-tuned DRIVEALIGN gains. Finally, I've modified the ISC guardian in such a way that it monitors the BIAS, and takes care of flipping all of the additional settings necessary to compensate for the bias change in the DOWN state. It had formerly had the DRIVEALIGN gain values hard coded, which was already bad news. Now the ESDOUTF gains (which have not been tuned / balanced as of yet) are flipped between -1 and +1; much easier to maintain. Also, I've added changing the CAL-CS settings to match as well, so the change in calibration will be taken care of as well. I would post the latest results from today's change measurements, but I've been stuck trying to get 1 second of EPICS data from NDS2 for about 4 hours now. Details ------------------ Before Flipping (to preserve my sanity, and minimize minus signs): - Moved DRIVEALIGN negative signs into the ESDOUTF bank: ETMX ETMY OLD NEW OLD NEW L2L -1 +1 -30 30 L2P -0.021 +0.021 0 0 L2Y -0.007 +0.007 0 0 and the ESDOUTF GAINs had all been positive unity, were flipped to negative unity so as to not yet actually flip the compensating sign. Then, I changed the ETMX bias sign: - Changed H1:SUS-ETMX_L3_LOCK_INBIAS from +9.5 to -9.5 [V_DAC] - (unlike before) The ISC_LOCK guardian (now) takes care of checking the sign of H1:SUS-ETMX_L3_LOCK_INBIAS, and adjusting the sign of - H1:SUS-ETMX_L3_ESDOUTF_[UL,LL,UR,LR]_GAIN from -1.000 to +1.000 (fixes the ESD stage longitudinal loop gain to match the bias sign change) - H1:SUS-ETMX_L3_ESDOUTF_LIN_FORCE_COEFF from +124518.4 to -124518.4 (fixes the linearization force coefficient to match the new bias sign) accordingly. - (like before) Accepted the new values in *all* SDF snap files, /opt/rtcds/userapps/release/sus/h1/burtfiles/ - h1susetmx_down.snap - h1susetmx_observe.snap - h1susetmx_safe.snap by loading in each table and accepting the values I've changed, followed by a commit to the userapps repo. - (like before) There's no need to make any further changes in the CAL-CS epics settings, because ETMX is not used in any capacity for calibration. Followed by the ETMY bias sign: - Changed H1:SUS-ETMY_L3_LOCK_INBIAS from -9.5 to +9.5 [V_DAC] - (unlike before) The ISC_LOCK guardian (now) takes care of checking the sign of H1:SUS-ETMX_L3_LOCK_INBIAS, and adjusting the sign of - H1:SUS-ETMY_L3_ESDOUTF_[UL,LL,UR,LR]_GAIN from -1.000 to +1.000 (fixes the ESD stage longitudinal loop gain to match the bias sign change) - H1:SUS-ETMY_L3_ESDOUTF_LIN_FORCE_COEFF from -124518.4 to +124518.4 (fixes the linearization force coefficient to match the new bias sign) accordingly. - (like before) Accepted the new values in *all* SDF snap files, /opt/rtcds/userapps/release/sus/h1/burtfiles/ - h1susetmy_down.snap - h1susetmy_observe.snap - h1susetmy_safe.snap by loading in each table and accepting the values I've changed, followed by a commit to the userapps repo. (This also involved *creating* a copy of the down.snap in the userapps repo, and changing the file in the target/h1susetmy/h1susetmyepics/burt/ directory to a soft link, as was already the case for the OBSERVE.snap and safe.snap) [Making sure Calibration is unaffected] - (like before) We must make sure that the CAL-CS replica of the ETMY actuation matches the SUS ETMY digital signal chain. However, because the CAL-CS model had not been restarted, and its SDF system had been kept up-to-date it did not lose the appropriate settings, so the settings for - H1:CAL-CS_DARM_FE_ETMY_L3_DRIVEALIGN_L2L_GAIN to +30.0 - H1:CAL-CS_DARM_FE_ETMY_L3_ESDOUTF_UL_GAIN to +1 - H1:CAL-CS_DARM_ANALOG_ETMY_L3_GAIN stays +1.0 - (unlike before) Again, to be consistent, I've changed the sign of the linearization force coefficient, - H1:CAL-CS_DARM_FE_ETMY_L3_ESDOUTF_LIN_FORCE_COEFF from +124518.4 to -124518.4 - (unlike before) Accepted the new values in *all* SDF snap files, /opt/rtcds/userapps/release/sus/h1/burtfiles/ - h1susetmx_observe.snap - h1susetmx_safe.snap by loading in each table and accepting the values I've changed, followed by a commit to the userapps repo. (Since there is no change between the "down" and "observation" state, a "down" .snap doesn't and need not exist.)
Something is wrong with ALS DIFF, is seems to saturate constantly. Is something wrong after the bias flip?
Looks like the Linearization Force Coefficient some how got flipped back to +124518.4. We fixed the sign there, and made sure it was coded correctly in the ISC_LOCK guardian and moved on. To 50+ W no less!
WP 5948 The code for the Beckhoff vacuum controls at end Y has been updated and restarted. This changes the PID controller for the CP LLCV from the FB_BasicPID supplied with the Tc2_Utilities library to a PI controller that I wrote (PIContollerFB in the Vacuum library). The changes include: - There is a manual control mode. Switching to manual control stops and resets the PI controller. - Changing the PI gains does not reset the controller. - The controller can be set to run at a slower rate than the PLC task (not in effect in manual mode). This is the cycle time on the medm screen. - There are user settable limits on the size of the integral term (anti-windup). These are the integrator high and low limits on the medm screen. - There are user settable limits on the output (not in effect in manual mode). These are the output high and low limits on the medm screen. - There is a user settable dead-band. The controller output does not change unless the absolute value of the difference from the last controller output is greater than the dead-band (not in effect in manual mode). - It has a user settable offset term in addition to the proportional and integral gains. This is essentially a constant offload of the integral term. The form of the controller is basically: Output = KP * Error + sum( KI * Error * (cycle time in milliseconds)) + Offset where KP is the proportional gain and KI is the integral gain I have updated the medm screen for CP7. I have also updated the overview medm screen to add links to the fill control screens next to each CP. One issue is that the displayed precision for the integral gain is too small. I will fix this at the next opportunity to restart the code. In the mean time it can be temporarily changed by right clicking on the medm screen, selecting PV Limits, clicking on the input field of the integral gain, changing the precision source to user specified, and changing the precision value to 6. This change will be lost when the medm screen closes. The code is currently controlling CP7 in PID mode, which also happened to get a LN2 delivery around the same time as the code change. The current settings are shown in the attached screenshot. The PID setpoint and offset may be hard to read, they are 92 and 80 respectively. The following channels were removed from the DAQ: H0:VAC-EY_CP7_400_LLCV_PID_ERR_CODE H0:VAC-EY_CP7_400_LLCV_PID_ERR_FLAG H0:VAC-EY_CP7_400_LLCV_PID_OUT_PCT H0:VAC-EY_CP7_400_LLCV_PID_TD H0:VAC-EY_CP7_400_LLCV_PID_TN H0:VAC-EY_CP7_400_LLCV_PID_TV H0:VAC-EY_CP7_LIC400_LLCV_POS_CTRL_PCT_DEAD_BAND The following channels were added to the DAQ: H0:VAC-EY_CP7_400_LLCV_PID_KI H0:VAC-EY_CP7_400_LLCV_PID_OFFSET H0:VAC-EY_CP7_400_LLCV_PID_ITERM_MAX_LIM H0:VAC-EY_CP7_400_LLCV_PID_ITERM_MIN_LIM H0:VAC-EY_CP7_400_LLCV_PID_OUT_MAX_LIM H0:VAC-EY_CP7_400_LLCV_PID_OUT_MIN_LIM H0:VAC-EY_CP7_400_LLCV_PID_OUT_DEAD_BAND
A reminder that we have two 18bit DAC cards which consistently fail autocal, both on reboot and IOP model restart. The cards are the first DAC cards in the systems h1susb123 and h1sush2a.
h1susb123
DAC0
chan | signal |
0 | ITMY M0 F1 |
1 | ITMY M0 F2 |
2 | ITMY M0 F3 |
3 | ITMY M0 SD |
4 | ITMY M0 LF |
5 | ITMY M0 RT |
6 | ITMY R0 LF |
7 | ITMY R0 RT |
h1sush2a
DAC0
chan | signal |
0 | MC1 M1 T1 |
1 | MC1 M1 T2 |
2 | MC1 M1 T3 |
3 | MC1 M1 LF |
4 | MC1 M1 RT |
5 | MC1 M1 SD |
6 | MC3 M1 T1 |
7 | MC3 M1 T2 |
Jenne, Nergis, Rana, Haocun
After all the PIT optical lever servos were on for both the ITMs and ETMs (27863), we measured the HARD Loops Gains again yesterday evening.
In the pictures attached, the red dots are mesurements when the PIT OLDAMPs are on for all the TMs, and also we have boosts on for those measurements (which explains the magnitude changes in low frequency and phase changes even for Yaw). The black curves are the measurements taken before the OL servos were on for the ETMs, and without boosts. The blue curves are the modeling results, which assume only OL on for ITMs.
.fig files attached.
WP 5941 The cdsfs1 computer was rebooted to fix a BIOS setting.
WP 5941 The computer controlling remote access for CDS was rebooted to fix a BIOS setting.
FRS 5725 WP 5940 Dataviewer has been updated to version 3.0.4 to properly display double precision trend data for Ubuntu 12, Ubuntu 14, Scientific Linux 6, and Gentoo systems. WP 5946 The NDS2 client software software has been updated to nds2-client-0.12.2 to provide better error messages on failure to deliver data for Ubuntu 12, Ubuntu 14, and Scientific Linux 6.
Sheila, Rana
We saw the dIzumi/dBallmer instability happening again tonight at the 19->23 W transition. Since this was happening in the cSoft DoF, we started debugging it and made some changes to see if we can damp the instability with a more rational loop than using oplevs or ISS.
Balancing the input Matrix:
We drove lines in cSoft and dSoft and then adjusted the relative gains for the X & Y TransMons so that the crosscoupling was < 15% (as measured at ~8 Hz). Confusingly, we only adjusted the matrix elements for dSoft. The existing cSoft matrix elements already gave a good decoupling. Before the adjustment we saw (via step response) that big DC steps in cSoft made steps in dSoft. After the matrix change this behavior is gone. The step responses seem well decoupled.
After much struggle, we were able to measure the soft loop shape. After turning up the gain from -0.05 to -1.14, we have a ~30 sec time constant and the UGF is a little below 100 mHz. We are able to see that the mismatch between the radiation pressure modified soft mode resonance and the digital compensator (FM10) is what makes cSoft go unstable if we turn up the gain further. Tomorrow we make a better filter and then see if we can damp the angular instability with an angular feedback loop.
Because we used up all the filter banks for the fundamentals, I made broadband filters for the high ETM 2nd harmonics.
ETMX 1003.664, 1003.778, 1004.078 and 1004.537 are damped with MODE9 FM1, FM4, FM10 (notch at 1003.907 Hz) with -50 gain.
butter("BandPass",4,1003.67,1004.54)gain(120,"dB")*gain(100,"dB")* ellip("BandStop",2,3,40,1003.807,1004.007)
This filter was later found to be ringing 1003.778 Hz. It has to be reconfigured. The individual damp settings for 1003.664, 1003.778, 1003.907, 1004.078, and 1004.537 are 0deg, +-180deg, 0deg, +-180deg, and 0 deg.
ETMY 1009.44 and 1009.49 are damped with MODE10 FM1, FM4 with +150 gain
butter("BandPass",4,1009.44,1009.49)zpk([0;0],[],1,"n")*gain(100,"dB")
ETMY 1008.45, 1008.49, and 1009.02 are damped with -60deg, -60deg, and 0deg (all + gain). No broadband filter has been made yet.
The other high amplitude modes that I haven't tried to damped are ETMX 1005.17, 1005.94, and 1006.5
ETMX MODE9 FM1 now covers 1003.667, 1003.778, and 1003.907. The face are correct here and should be damped with positive gain setting.
ETMY MODE 9 FM1 now covers 1008.45, 1008.49, 1009.02. The phase is close to what damped last night. Still has to be tested.
(John, Gerardo)
CP5 level has been changed from 92% to 84%. This is going to generate alarms since 84% is the low level alarm, please do not ignore alarms below 84%.
CP5 is now in PID control.
I think Gerardo meant to say you can ignore alarms near 84% but if the pump level falls much below that - say 74%; then action should be taken.
If this is the case you may set the liquid level control valve (LLCV) to manual and use the current manual setting of 90%. Or call one of us.
Vacuum staff will have alarm texts sent to their cell phones if the level drops below 80% (or above 99%)
Nergis, Sheila, Haocun
As posted in alog 27820, the IMC transfer function has a high gain around 800kHz, and we thought that may be reduced by lowering the FSS loop gain, which was proved to be true.
We reduced the FSS loop gain for 6dB (the common gain from 20dB to 14dB; the fast gain from 22dB to 16dB) , and the IMC loop gain dropped about 16dB from -4dB to -20dB at 800kHZ.
The measurements were taken from 10Hz to 5MHz. The green curve was measured before reducing the FSS gain, and the yellow one was measured after lowering the gain.
Currently, we left the FSS loop gain values to be the lower ones, which can be turned back up later if needed.
I set the fast gain back to 22dB, to keep the crossover the same.
Nutsinee, Kiwamu, Alastair (remotely)
We have aligned the CO2 Y beam relative to the main interferometer beam. We are ready for various TCS tests again.
We aligned the beam by doing the same exercise as Aidan and Alastair did back in this February (25353). According to what Aidan calculated, the precision of the adjustment is about 20 mm which should be good enough (recall that the CO2 beam size is twice bigger than that of the main laser i.e. 100 mm or so in radius). We hooked up an analog function generator to the modulation input of the AOM driver which resides on the right hand side of the TCSY table. We drove it with an offset of 0.5 V and an amplitude of ~0.2 V at a frequency of 50 Hz. The frequency is chosen to be higher this time because the interferometer had higher noise floor below 40 Hz (dominated by CHARD control noises). We steered pico motor G which corresponds to a mirror on top of the periscope. After an iterative adjustment, we ended up with [x, y] = [-17500, 27000] in the pico motor readout. Note that these values are almost comparable to the previous adjustment by Aidan and Alastair. As a result of the alignment, the CO2 coupling to DARM increased roughly by a factor of 10 -- indicating a better overlap between the CO2 projection and the main interferometer beam.
Side note is that we saw a slow drift (with a small oscillation on a time scale of 10 min.) in the observed CO2 power during the adjustment in which the CO2 power monotonically kept decreasing by 10% or so over an hour or two. After unplugging the function generator, we also saw the power drifting back to the nominal power at a faster rate. A seemingly coherent behavior was visible yaw and pitch of QPDs A and B. No idea why.
This drift might be worth checking into over a longer time. It's not impossible to think of ways in which lab temperature could cause aligment drifts.
Conor, Jeff K Summary: - Conversion of ISI Suspoint motion into the DoF basis works for the arms, with limited fidelity. - Corner station DoFs seem not to work, possibly some problem with inclusion of the Beamsplitter. - IPC communication between ISI and SUS at ETMY is spoilt somehow. The GS-13s on stage 2 are used as witnesses for residual motion. Their outputs are calibrated to nm, and converted to suspension point motion using Euler matrices (Cart2Eul). The output is in the local suspension coordinates. For example, the channel 'H1:ISI-ITMX_SUSPOINT_ITMX_EUL_L_DQ' is the longitudinal motion of ITMX, which is along the normal vector pointing outward from the HR surface, in the global +X direction. These suspension point motions are IPC'd to the OAF model, and in the case of the ETMs this involves some multiplexing/AI-filtering for communication down the arm. In OAF they are combined into the IFO degrees of freedom based on T1500610 . As a sanity check, I fetched the ISI-model Suspoint channels and matrix'd them into the IFO DoFs in Matlab, for comparison with the OAF DoF channels. For the arms (XARM, YARM, CARM, DARM), things seem to be somewhat okay. I confirmed this by eye, and then took the spectrum of the subtraction (attachment 1, CARM_Spectrum). The residual is consistent with the dynamic range of single-precision floats (about 10^9), at least at high frequencies. A quick software-only transfer function using four poles at 0.1Hz and white-noise injection in a spare filter bank shows a similar total dynamic range (attachment 2, DTT_dynamic_range). The anti-imaging filters, for transmission of the ETM signals along the arm, should allow a considerably smaller residual than we see at low frequencies, and I don't really know what else might cause this. The corner station DoFs are substantially wrong, visible directly in the time series' (eg attachment 3, MICH_time_series). Since MICH only uses the ITMs (confirmed to be 'okay') and the Beamsplitter, presumably the difference arises there. PRCL and SRCL are similarly incorrect. Document T1500610 has some minor errors in the Suspoint->IFO-basis definitions, but the current matrix has correct values as far as I could see. It also points to the Suspension model versions of the Suspoint motion, eg 'H1:SUS-ITMX_M0_ISIWIT_L_DQ', but the model uses the ISI versions. Initial testing revealed discrepancies between: 'H1:ISI-ETMY_SUSPOINT_ETMY_EUL_L_DQ' 'H1:SUS-ETMY_M0_ISIWIT_L_DQ' visible in attachment 4 (ETMY_IPC_issue). The other 3 test masses didn't show this gross level of disparity.
The problem with the corner station calculations are a model mapping error. I pointed this out to Jeff but he must have thought I fixed it or he just spaced it out given his usual very full to-do list. I've never edited the OAF model and did not feel comfortable doing so. Attached is the errant part of the model. The BS PRM PR2 and PR3 are all mis-mapped in this section.
Dave, Conor, Jenne, Hugh
Jenne is fixing the mapping mis-wire for the corner station calculations.
Dave checked the data path and found the SUS and ISI versions of the CART2EUL matrix for the ETMY were not the same. This looks likely to be the issue rather than an IPC problem.
I checked the values against the data file I used to populate the matrices for all the suspensions and it still agrees. I suspect the values in the SUS ETMY matrix are out of date.
See alog 11036 for more details: Data file is
/opt/rtcds/userapps/release/isc/common/projections/ISI2SUS_projection_file.mat
Here is some detail on the GS13 signal paths. The six GS13 signals coming out of the ISI model are split, with one set going via Dolphin IPC to the SUS system, and the other set going through the ETMn_CAL into the ETMx_SUSPOINT part, in which is passes through a CART2EUL matrix. The SUS model receives the six dolphin channels, passes these through the ISIINF part, then through its CART2EUL matrix into the ISIWIT. It is these two CART2EUL matrices which have identical settings at ETMX and are slightly different at ETMY.
J. Kissel I've compiled, installed, and restarted the OAF model with the SUSPOINT to IFO basis transformation bug fix, and committed the top level model, /opt/rtcds/userapps/trunk/isc/h1/models/h1oaf.mdl Attached is a screen shot showing the current and correct channel ordering.
J. Kissel I've also updated the SUS version of the ETMY CART2EUL matrix (i.e. H1:SUS-ETMY_M0_CART2EUL channels) with the values found in /opt/rtcds/userapps/release/isc/common/projections/ISI2SUS_projection_file.mat that was apparently discrepant in only *some* of the rotational terms, and only by ~10%. I can't explain why these were off, and I'd trended the values for the past 850 days (with the stop time of June 2015, so I covered the time install time mentioned in LHO aLOG 11036) and they've not been changed. One of life's mysteries, I suppose. Fixed now! For the record, the new values are | L | | 0 -1.0000 0.2000 0 -0.2823 0 | | X | | T | | 1.0000 0 0.4294 0 0 -0.2823 | | Y | | V | = | 0 0 0 1.0000 -0.4294 0.2000 | | RZ | | R | = | 0 0 0 0 0 -1.0000 | | Z | | P | | 0 0 0 0 1.0000 0 | | RX | | Y | | 0 0 1.0000 0 0 0 | | RY |
Also, I posted some analysis of the relative motion between HAM2 and HAM3 in the DCC https://dcc.ligo.org/G1601390 differential Z is really small. differential X kind of sucks at the microseism. Not sure how much it matters for the IMC, but it is worth thinking about. I think there is some fruitful work to be done here - if it would be useful to reduce the relative motion of the ISI tables in the corner at the microseism.
J. Kissel WP #5932 Today's model modifications come in three parts: (1) Independent Synchronized Oscillators for each isolation stage of the QUAD for calibration lines (2) Updated CAL-CS model with better demodulation scheme that spits out coherence and uncertainty (3) Changed all CAL-DELTAL and CAL-DARM channels to double precision and removed whitening Below are all the details. ------------- Part (1) In order push the PCAL vs. SUS actuation calibration line cancelling scheme for ER9/O2 forward (see T1600218 and T1600215), I've installed independent, longitudinal, synchronized oscillators in each of the UIM/L1, PUM/L2, TST/L3 stages of all of the QUAD models. See first attachment for screenshot of the QUAD OVERVIEW screen that now has the CAL_LINE block beneath every LOCK bank. Sadly, due to the recent split in QUAD library part models, I'd forgotten to add the needed EPICs channel for GPS synchronization to the ITMs. We'll install them tomorrow morning. I've committed the following new models: /opt/rtcds/userapps/release/sus/common/models/ Sending FOUROSEM_DAMPED_STAGE_MASTER_WITH_DAMP_MODE.mdl <-- Used in PUM/L2 stages Sending FOUROSEM_STAGE_MASTER_OPLEV_TIDAL.mdl <-- Used in UIM/L1 stages Sending QUAD_MASTER.mdl <-- Added EPICs record for GPS sync time on TST/L3 stage for ETMs and accordingly modified MEDM screens: M SUS_CUST_QUAD_ITM_OVERVIEW.adl A + SUS_CUST_QUAD_ISTAGE_CAL_LINE.adl D SUS_CUST_QUAD_L3_CAL_LINE.adl M SUS_CUST_QUAD_OVERVIEW.adl ------------- Part (2) In addition, as a continuation of the improvements to using those calibration lines to track changes in the DARM loop parameters, I've followed Joe's instructions (see LHO aLOG 26491) and updated the CAL-CS model to demodulate PCAL and DARM error signals at given frequencies and produce parameter estimates, coherence estimates, and even uncertainty estimates. Darkhan will be working on commissioning the infrastructure with Joe. ------------- Part (3) Finally, I've converted all of the calibrated DARM channels to double precision. *EXCEPT* for DELTAL_EXTERNAL, which is needed to display on the wall in the control room via DTT (which sadly, cannot yet handle double precision; see CDS Bug 1003). As a result, and as per Joe's advice I've turned OFF all dewhitening filters that condition the following (new) channels stored in the frames: H1:CAL-DARM_CTRL_WHITEN_OUT_DBL_DQ H1:CAL-DARM_ERR_WHITEN_OUT_DBL_DQ H1:CAL-DELTAL_CTRL_DBL_DQ H1:CAL-DELTAL_CTRL_PUM_DBL_DQ H1:CAL-DELTAL_CTRL_TST_DBL_DQ H1:CAL-DELTAL_CTRL_UIM_DBL_DQ H1:CAL-DELTAL_RESIDUAL_DBL_DQ We need to investigate if we're now happy with the signal fidelity without whitening or if we just need to re-assess the whitening. Again, I've retained single precision on H1:CAL-DELTAL_EXTERNAL_DQ, so its whitening filter remains ON.
J. Kissel, J. Betzwieser Joe called to let me know that I'd misinterpreted the fixed oscillator part that we chose to use (of the two; see T1600143). Turns out this version of the fixed phase oscillator automatically synchronizes to GPS time 0 (i.e. Jan 4 1980), so there's no need for the extra EPICs record input to the oscillator that specifies the GPS time. So, in opposition to what's said above, the ITM models are fine; we need to take the GPS EPICs record *out* of the ETMs. Will do so tomorrow.
J. Kissel All QUAD Models have been restarted sans EPICs record for synchronization (the ITMs needed a restart to absorb the removal from the L1 and L2 stage common library parts). MEDM screen has been updated as well. I've committed the following to the repo. /opt/rtcds/userapps/release/sus/common/medm/quad/ Sending SUS_CUST_QUAD_ISTAGE_CAL_LINE.adl /opt/rtcds/userapps/trunk/sus/common/models/ Sending FOUROSEM_DAMPED_STAGE_MASTER_WITH_DAMP_MODE.mdl Sending FOUROSEM_STAGE_MASTER_OPLEV_TIDAL.mdl Sending QUAD_MASTER.mdl
Before doing the sat amp power cycle, we first tried a coil driver power cycle on a few of our funny OSEM sets. This did not appear to clear the errant noise in any of the 4 cases. We then embarked on the sat amp power cycle which cured the 2 shown in the above list. Tomorrow we hope to revisit ITMY R0 RT and SR2 M1 which we have left off troubleshooting today with only coil driver OFF spectra. (Betsy, tomorrow you should use the attached spectra as a jump off point.)
TBC... Note the wildly different looking symptoms both of which were seen by Lundgren in 20675 AUG 2015.
Attached is the ITMY L2 OSEM signal spectra shown from before and after today's fix. The PRM M2 OSEM before and after-fix spectra are very similar to this.
ETMX High freq turn up during LOCK ACQ, not a stand alone OSEM signal feature.
ITMy R0 RT investigation - this morning Richard and Fil performed another round of tests on the ITMy R0 RT (shared cable and electronics with R0 LF, M0 RT, M0 LF). After power cycling the SAT box, other SAT box cable reseating, and reseating of the main cable to the chamber, the noise on this channel still exists.
SR2 M1 bouncy noise on 3 of 4 TOP investigation - Richard and Fil powert cycled the Sat AMp box for this set of 4 OSEMs, but the noise is still there.
TBC...