I injected into the 2nd loop board via PSL-ISS_TR (3rd looop filter) and SR560, and measured the transfer function from the readback of the analog input (H1:PSL-ISS_SECONDLOOP_PD_58_SUM_OUT, which is 32k channel) to the readback of the analog output ( H1:PSL-ISS_SECONDLOOP_SIGNAL_OUTPUT, which I think is in the 1st loop board) when the gain is set to 0, BOOST off, integrator off.

I was confused because of an additional 500Hz pole, but it seems like this was a questionable 500Hz digital pole in H1:PSL-ISS_SECONDLOOP_SIGNAL FM1. Anyway, in the attached, dots are as measured but after counter-compensating for the questionable 500Hz digital pole, and the lines are what is expected from D1300439 and S1400214.

The analog TF of the board itself should be something like zpk([1, 100, 8.46k, 10k], [0.1, 0.5, 500, 33.9k], 350). Yes there's 500Hz pole in analog. This is like one 0.1Hz pole up to 100Hz with some funny additional things (but don't forget SR560 with AC coupling and 10Hz pole, SR560 is used as a poor man's dewhitening to cut the DAC noise).

To make the 3rd loop design without 2nd loop somewhat easier, I made a simple zpk([0.1;0.5], [1;10; 50], 1) in FM9 of H1:PSL-ISS_TR called boardComp to get rid of p=[0.1, 0.5] and z=1. The potential problem of this is that the SR560 might rail. If this happens, we need something better.

Anyway, the starting point is to turn this filter on, then set the gain to whatever it was originally and divide it by 350, and measure the OLTF of the third loop without the second loop while the loop is open.

Maintenance Day Log:

• 14:45 - Cris S to EX wind fence work
• 14:56 - Jeff K starting charge measurements
• 14:57 - Jeff B out of PSL
• 15:25 - Joe to LVEA for battery charging
• 15:34 - Richard to LVEA coil driver reset in beir garten
• 15:35 - Gerardo to LVEA to pull cable from rack in west bay to top of HAM1
• 15:40 - Joe out
• 15:41 - Hugh to LVEA inventory control
• 15:57 - David M to LVEA to plave seismometers
• 16:00 - N2 delivery at gate
• 16:05 - Charge measurements done
• 16:09 - Hugh to EX for HEPI fluid checks
• 16:21 - Jeff K done with End Quad model restarts
• 16:25 - Karen to MY
• 16:29 - Vinny to LVEA to look at mike, not the person
• 16:32 - Richard to CER to break stuff
• 16:37 - Hugh from EX to EY HEPI
• 16:46 - Carl B to LVEA to measure PI ITMY
• 16:50 - Vinny out
• 17:02 - Karen from MY to EY
• 17:02 - Jeff B unloading from mech room
• 17:15 - Jeff B done
• 17:33 - Joe to LVEA to unplug chargers
• 17:41 - DAQ restart
• 17:45 - Cristina MX to EX
• 17:47 - Karen leaving EY
• 17:49 - Joe done
• 17:58 - ASC model restart
• 18:12 - Fil back from ends, to LVEA to take pictures
• 18:30 - Ed to CER to help Fil pull PUM chasis
• 18:33 - Jenne to LVEA to join David M
• 18:37 - Jeff K to LVEA to check on status of work
• 18:58 - Gerardo out
• 18:58 - Ed out
• 19:10 - Ed to LVEA replace PUM chasis
• 12:15 - TJ to LVEA to transition laser status
• 12:35 - LVEA Laser SAFE
• Richard, Fil, Ed in and out and in and out to imvestigate noisy osems on ITMs, PRM, SR2
• 20:41 - NSF tour into LVEA
• 20:42 - Jeff K to EY to turn on ESD
• 21:40 - Tour out, David M out

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.)  

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

h1sush2a

DAC0

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.

WP 5941

The cdsfs1 computer was rebooted to fix a BIOS setting.

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

(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.

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.

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.

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.

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.