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ID Date Authorup Type Category Subject
  7086   Sun Aug 5 13:48:40 2012 DenUpdateCDSMove to RCG 2.5 tag release

Quote:

I moved the RCG to the advLigoRTS-2.5 tag

 After that RFM -> OAF communication through PCIE became bad again. Inside CommData2.c cache flushing is not allowed

// If PCIE comms show errors, may want to add this cache flushing
            #if 0
            if(ipcInfo[ii].netType == IPCIE)
                clflush_cache_range (ipcInfo[ii].pIpcData->dBlock[sendBlock][ipcIndex].data, 16);
            #endif

As a result, a significant part of MC_F and other signals is lost during RFM -> OAF transmission (270 - 330 out of 2048 per second)

erros.png   overview.png    oaf.png

 


Last time when I replaced 0 for 1, it suspended SUS machine because of the code bug. Alex modified a couple of files in the old version and it started to work. Do you know if this bug is fixed in the new version?

  7111   Tue Aug 7 23:33:34 2012 DenUpdateEnvironmentNearby EQ

Quote:

 Just felt an EQ. Impulse moved some vertical blinds by several mm.

Tue Aug 07 23:26:06 2012 

 All optics except MC2 and ETMX are crazy

watchdogs.png      mc1.png    gur.png

  7147   Fri Aug 10 17:38:29 2012 DenUpdatePEMclassify seismic c code

Quote:

Den and I also had trouble with a simple for loop in our model, so we talked to Alex who noted that the -O3 compiler unravels for loops in a buggy way. Thus, we have compiled c1pem using the -O compiler. 

Alex also modified RCG script to generate -O in the Makefile for c1pem model:

controls@pianosa:/opt/rtcds/rtscore/release/src/epics/util 127$ svn diff
feCodeGen.pl 
Index: 
feCodeGen.pl
===================================================================
--- 
feCodeGen.pl (revision 2999)
+++ 
feCodeGen.pl (working copy)
@@ -3183,7 +3183,12 @@

print OUTM "\n";
}
print OUTM "ALL \+= user_mmap \$(TARGET_RTL)\n";
+# do not optimize c1pem
+if ($skeleton eq "c1pem") {
+print OUTM "EXTRA_CFLAGS += -O -w -I../../include\n";
+} else {
print OUTM "EXTRA_CFLAGS += -O3 -w -I../../include\n";
+}
print OUTM "EXTRA_CFLAGS += -I/opt/gm/include\n";
print OUTM "EXTRA_CFLAGS += -I/opt/mx/include\n";

  7150   Fri Aug 10 21:37:15 2012 DenUpdatePEMgur, sts noise

 Using Guralp, STS-2 and Trillium I compared Gur and STS-2 self-noise assuming that Trillium noise is not worse then STS-2 noise.

gur_sts_noise.png

Interesting that STS-2 (or Trillium if its noise is worse) noise is not too much better then Guralp noise.

  7153   Sat Aug 11 18:57:07 2012 DenUpdatePEMseismometer location

STS-2 - end of X arm

GUR 2 - isolation box

TRILLIUM - 1Y3 (DC power supply uses 1Y3 AC power, please do not close the door completely)

GUR 1 - end of Y arm

Now we have several "triangular seismic antennas". Different configurations can be chosen to compare the results.

  7157   Mon Aug 13 01:33:55 2012 DenUpdateGeneralMysterious banging on emergency door

Quote:

[Masha, Sasha]

Sorry to spam the e-log, but did someone come knock loudly on the emergency exit door a few moments ago? It gave Sasha and I quite a fright, and we are rather worried.

 Probably, security. You can call 5555 and ask them. Otherwise you can ask them to come and check everything.

  7176   Tue Aug 14 11:49:15 2012 DenUpdateCDSDebugging of c1sus machine and c1rfm models

Quote:

 

  We might just need to reduce the load on c1rfm, maybe by introducing a c1rfm2?

 

 A huge data flow goes from PEM to OAF through RFM. I think we need to make PEM and OAF run on the same machine and transmit signals through the shared memory.

  7185   Wed Aug 15 00:52:17 2012 DenUpdateWienerFilteringfilter calculation

A Matlab script to calculate Wiener filter coefficients and convert fir to iir is ready. Input is a file with zero mean witness and desired signals, output is a Foton zpk command to specify iir filter.

The plot shows comparison of offline fir , iir and online iir filtering. Spectrum below 4 Hz is still oscillating due to acoustic coupling, this is not a filtering effect. At 1 Hz actuator is badly compensated, more work should be done. Other then that online and offline filtering are the same.

wiener.png

  7189   Wed Aug 15 10:40:16 2012 DenUpdateCDSaa filters

The lack of AA filter for MCL signal is RFM model strongly disturbed entering to OAF signal

aa.png

  7193   Wed Aug 15 13:24:12 2012 DenUpdateCDSRFM -> OAF

Transmission of signals between RFM and OAF is bad again. Now we do not see any errors in IPC_ERR monitors so models think that they get all data but the data is wrong

oaf.png

  7226   Sat Aug 18 19:29:56 2012 DenUpdatePEMEM 172 microphones noise

I've put EM 172 microphones inside Steve's isolation box to measure their noise. I've attached mics to each other and aligned them using the tape.

At low frequencies (below 1 Hz) the noise is limited by ADC as there is a 10 Hz high-pass filter inside mic readout box.

ADC noise is measured by splitting the signal from 1 mic into 2 ADC channels.

em172.png

  7230   Sun Aug 19 19:02:47 2012 DenUpdateCDSPEM -> RFM -> OAF

Data from PEM now goes directly to OAF without using RFM. Transmission RFM -> OAF errors are gone as RFM has to read 30 channels less now.

Again kernel "protection error" occured as before with PEM model so OAF model could not start. I changed optimization flag to -02, this fixed the problem.

  7234   Mon Aug 20 13:02:57 2012 DenUpdateAdaptive Filtering1 Hz resonance

Static filter was adjusted to filter 1 Hz resonance in MCL and it could do it. Stack is not great in this experiment due to the phase mismatch. I'll fix it.

1hz.png

  7252   Wed Aug 22 20:33:51 2012 DenUpdateAdaptive FilteringMC_L in ARMS

Jenne and I did adaptive filtering of MC_L and measured how X and Y ARM control signals change compared to non-filtered MC_L. We did the test during 1.5 Hz seismic noise activity and adaptive filter was able to subtract it. However, it adds noise at high frequencies, It is not seen in MC_L but it is present in the ARMs control signals.

I'll investigate this problem. May be we need to reduce adaptation gain. In this experiment it was 0.1 and adaptive filter convergence time was equal to 1-2 mins.

 oaf_arms.png

  7267   Fri Aug 24 00:23:20 2012 DenUpdateModern Controlfeedback using LQG method

I did a simulation of linear quadratic gaussian (LQG) controller applied to local damping. The cost function was frequency shaped to have a peak at 1 Hz. This technique prevents the controller from adding sensor noise at high and very low frequencies.

Noise was simulated to have 1/f spectrum (seismic) multiplied by stack with a resonance at 4 Hz with Q=5.

model.png         feedback_lqg.png

 

 

  7270   Fri Aug 24 13:22:19 2012 DenUpdateModern Controlcavity simulation

I did a simulation of a cavity, feedback signal was calculated using LQG controller. I assumed that there is not length -> angle coupling and 2 mirrors that form the cavity have the same equation of motions (Q and eigen frequencies are the same). Cost functional was chosen in such a way that frequencies below 15 Hz contribute much more then other frequencies.

model.png             controller.png              cavity.png

Gains in the controller are calculated to minimize the cost functional.

cavity_lqg.png

This technique works well, but it requires full information about the system states. If we do not assume that cavity mirrors have the same equations of motion then we need to apply Kalman filter to approximate the position of one of the mirrors.

  7384   Fri Sep 14 01:05:36 2012 DenUpdateSUSMirrors being installed on active TTs

Quote:

I have given Den 4 G&H R>99.99% mirrors to be installed on the 4 active tip tilts. 

 I've installed the mirrors on 4 tip-tilts. I was able to align 3 of them in pitch, the last one has a screw with damaged thread, I'll continue with it tomorrow.

Alignment accuracy in pitch is ~0.1 mrad. Mirrors oscillate a lot probably due to air flow coming from the side wall.

  7392   Fri Sep 14 21:03:02 2012 DenUpdatePEMBS and AS tables

I've measured seismic and acoustic noise on BS and AS tables. It seems that horizontal motion of BS table is ~1.5-2 times more then AS table in the frequency range 5-50 Hz.

Edit by Den: this was POI table, not BS!

vert.png  horiz_4_50.png

acoustic.png      coh.png

  7394   Sat Sep 15 18:46:50 2012 DenUpdatePEMmicrophone location

I've suspended microphones around the lab

C1:PEM-MIC_1 - MC2
C1:PEM-MIC_2 - ETMX
C1:PEM-MIC_3 - PSL
C1:PEM-MIC_4 - AS
C1:PEM-MIC_5 - POI
C1:PEM-MIC_6 - ETMY

mics.png

  7395   Sat Sep 15 20:27:54 2012 DenUpdatePEMBS and AS tables

Quote:

I've measured seismic and acoustic noise on BS and AS tables. It seems that horizontal motion of BS table is ~1.5-2 times more then AS table in the frequency range 5-50 Hz.

Edit by Den: this was POI table, not BS!

 This seismic measurement is for BS and AS tables.

bs_as_h.jpg       bs_as_v.jpg

  7412   Wed Sep 19 17:48:47 2012 DenUpdateModern ControlETMX

Time domain control using LQR technique is now applied to ETMX sus position. The plan was to do it for oplevs, I'll do it after the vent.

The cost function for state space variables was determined by TF  900 / (s + 30)^2. There was no penulty imposed for velocity, only for position. We can try that configuration as well.

etmx_suspos.png

  7424   Thu Sep 20 22:52:38 2012 DenUpdateMachineLearningFeedback controller

Quote:

I have uploaded to my directory a directory neural_plant. The most important file is reference_plant.c, which compiles with the command

 We would appreciate some plots. Learning curves of recurrent NN working as a plant are interesting. For harmonic oscillator your RNN should not contain any hidden layers - only 1 input and 1 output node and 2 delays at each of them. Activation function should be linear. If your code is correct, this configuration will match oscillator perfectly. The question is how much time does it take to adapt.

Does FANN support regularization? I think this will make your controller more stable. Try to use more advanced algorithms then gradient descent for adaptation. They will increase convergence speed. For example, look at fminunc function at Matlab.

  7428   Fri Sep 21 22:43:51 2012 DenUpdateSUSTT alignment

I did TT alignment using red laser and QPD.

P9210079.JPG       P9210092.JPG

 I had a problem aligning TT with frame number SN-035 as some screws are damaged so all what I could move were 2 blades on the sides of the mirrors. But this was not enough to align pitch and yaw simultaneously.  It is possible to align pitch only, but then I got a huge yaw angle (~0.05-0.1 rad). The only option I had was to make a reasonable alignment in yaw and then suspend several washes on the screw on the bottom of the mirror to align pitch.

Attached are flag positions inside coils. 1 - SN034, 2 - SN012, 3 - SN006, 4 - SN035. For each TT there are 4 pictures with flag 1-4: UL, LL, UR, LR

Attachment 3: 1.pdf
1.pdf 1.pdf 1.pdf 1.pdf
Attachment 4: 2.pdf
2.pdf 2.pdf 2.pdf 2.pdf
Attachment 5: 3.pdf
3.pdf 3.pdf 3.pdf 3.pdf
Attachment 6: 4.pdf
4.pdf 4.pdf 4.pdf 4.pdf
  7429   Sat Sep 22 01:03:30 2012 DenUpdatePEMETMY table

I've installed Guralp readout box back and it turned out that it does not work with voltage provided from the rack (+13.76 0 -14.94).  +/-12 voltage regulators inside the box convert it to -0.9 0 -12. I've connected the box to +/-15 DC voltage supply to measure seismic motion at the ETMY table. Readout box works fine with +/- 15.

Seismic noise on the ETMY table measured to be a few times higher then on the floor in horizontal direction in the frequency range 50 - 200 Hz. Attached are compared spectrums of X, Y and Z motions.

Attachment 1: X.pdf
X.pdf
Attachment 2: Y.pdf
Y.pdf
Attachment 3: Z.pdf
Z.pdf
  7430   Sun Sep 23 22:40:48 2012 DenUpdateModern ControlMC_L locking

I've applied LQR approach to MC_L locking. Results show that LQR does not make MC_F signal smaller below 0.3 Hz in contrast with classical locking. This might indicate that in this frequency range we see sensing noise as LQR was provided with state-space model of MC only so it tries to reduce displacement noise. It is also possible that state-space model is not accurate enough.

 

Attachment 1: LQR_MCL.pdf
LQR_MCL.pdf
  7443   Wed Sep 26 17:09:15 2012 DenUpdateSUSTT

  [Koji, Steve, Den]

TT alignment is fine, yaw damping is satisfactory, pitch damping is slow. We might want to add magnets to the mirror and attach blades to the frame for pitch edge current damping.

We are moving towards electronics testing.

  7483   Thu Oct 4 22:16:40 2012 DenUpdatePSLPMC is locked

PZT monitor is not lying to us, I've measured it with a voltmeter. But PMC SERVO is still interesting. If I break the loop after PMCERR signal monitor (C1:PSL-PMC_BLANK=0), I can change PZT voltage from 0V (C1:PSL-PMC_RAMP = -7.3) to 132V (C1:PSL-PMC_RAMP=-10.0). If I break the loop by enabling TEST1, PZT voltage goes up to 294 V, though voltage on the TEST1 and MIXER MON is 0.

  7485   Thu Oct 4 22:35:16 2012 DenUpdateSUSHow about the slow machines?

Quote:


Based on the elog entries, I assume they have not been burtrestored...

 Do you know how to burtrestore or restart slow machines?

Edit by Den: I did burtrestore of c1psl.snap from 2 days ago. Still slow machines behave not normal. For example, if I sweep C1:PSL-FSS_SLOWDC, SLOW monitor value does not change.

  7487   Fri Oct 5 00:29:34 2012 DenUpdatePEMreadout box power

Guralp readout box received +13.7 /0/ -15V instead +15V because of the broken fuse. Power provided by the source is normal.

Edit by Den: I've found a similar fuse on one of the tables and borrowed it. Guralp is not working again.

  7488   Fri Oct 5 01:36:49 2012 DenConfigurationPEMchanged PEM DQ channels

Quote:

We should do this wherever possible so that our channels will have real calibrations associated with them.

Next we should up the rate at which the model runs up to 16 kHz so that we can record the microphones at 16 kHz. FM radio has information up to 20 kHz. AM radio goes up to ~8 kHz. We should be at least as modern as AM radio. How do we make the change? How do we make sure the FOTON file stays OK?

 I've added calibration gains to Guralp (to um/sec) and EM172 (to Pa) channels.

We can run PEM at 16 kHz. I think Foton file stores both sos-representation and filter commands which are independent of the sampling frequency, so it should be possible to change model sampling frequency quickly.

In fact, we can save data at 64 kHz from iop models. I've done this once with MC_F channel. However, I did not test EM172 noise at frequencies > 1 kHz.

  7490   Fri Oct 5 11:11:00 2012 DenUpdatePEMreadout box power

Quote:

Guralp readout box received +13.7 /0/ -15V instead +15V because of the broken fuse. Power provided by the source is normal.

Edit by Den: I've found a similar fuse on one of the tables and borrowed it. Guralp is not working again.

 I've meant Guralp is NOW working again 

  7496   Sun Oct 7 15:05:42 2012 DenUpdateSUS MC2 sus damping restored

Quote:

This is the third morning in a row that the MC2 was tripped.

 MC2 was tripped again. I think the answer is that watchdog's critical value was too small C1:SUS-MC2_PD_MAX_VAR = 10, so seismic could trip MC2. I've changed the value to 100.

mc2.png

  7497   Sun Oct 7 23:39:10 2012 DenUpdateModern Controlstate estimation

I've applied online state estimation technique using Kalman filter to LQG controller. It helps to estimate states that we do not measure. I've considered MC2 local damping, we measure position and want to estimate velocity that we need for control. We can either differentiate the signal or apply state estimation to avoid huge noise injection at high frequencies. In state estimation we need to know noise covariance, I've assumed that LID sensor noise is 0.1 nm. Though covariance can be calculated better.

In the time-domain figure C1:SUS-MC2_SUSPOS_IN1 = MC2 postion, C1:SUS-MC2_SUSPOS_OUT = MC2 velocity obtained by differentiation, 2 other channels are estimations of position and velocity.

Attachment 1: est_time.png
est_time.png
Attachment 2: est_freq.pdf
est_freq.pdf
  7503   Mon Oct 8 12:34:52 2012 DenUpdateModern Controlstate estimation

Quote:

 

 I guess that the estimated state has the same low pass filter, effectively, that we use to low pass the feedback signal in SUSPOS. I wonder if there is an advantage to the state estimation or not. Doesn't the algorithm also need to know about the expected seismic noise transmission from the ground to the optic?

 I think state estimation and optimal control are two different techniques that are often used together. Sometimes (as for pendulum) we can use LQG without state estimation as we need only position and velocity. But for more complex systems (like quad suspension) the states of all 4 masses can be reconstructed in some optimal way using information from only one of them if the dynamics is sufficiently well known. When current system states are measured/estimated we can apply control where all our filters are hidden.

 The algorithm needs to know about expected seismic noise transmission from the ground to the optic, but it might be not very precise. I gave it some rough estimate, there are better ways to do it. I think that we'll understand whether we need state estimation or not when we'll move to more complex systems. Brett uses a similar approach for his modal control. Interesting if these methods + seismometer readings will be able to say if one of your sensors is noisier then others.

 

 

 

 

 

 

 

 

 

  7511   Tue Oct 9 17:16:14 2012 DenUpdateSUSdiagonalization

I went inside to align the beam on WFS and noticed that oscillations in yaw are ~10 times stronger then in pitch. I've plot rms of pitch and yaw measured by LID sensors and saw that MC3 yaw rms motion is a few times larger then pitch.

Also MC1 input diag matrix does not diagonalize signals for pitch and yaw. In the spectrums of these signals all 4 resonance are equally seen during the free swinging. I think we should rediagonalize MC1.

Another thing is that if MC1 and MC3 are on the same stack,  pitch and yaw spectrums of these mirrors should be comparable. But MC1 signal is ~2-3 times larger then of MC3. I think we should correct calibration.

Attachment 1: mc123_rms.pdf
mc123_rms.pdf
Attachment 2: mc1_diag.pdf
mc1_diag.pdf
Attachment 3: mc123_rms.pdf
mc123_rms.pdf
  7522   Wed Oct 10 20:27:40 2012 DenUpdateIOOMCL, WFS triggers

I've added MCL and WFS stop triggers into C1MCS/SUS model. Threshold value of MC_TRANS can be changed in the text entry located in MC2_POSITION medm screen. I tried 2 cases: trigger either blocks signal before MCL filter bank input or after output. Due to filter history in the 1 case MC2 was still slightly disturbed (C1:SUS-MC2_ULPD_VAR ~= 15) right after unlock. In the second case there was no disturbance as we zero output signal, but then I had to add "clear history" command to the mcup script.

WFS triggers block the signal before ASCPIT/YAW filter bank.

MC2_POS.png

Attachment 2: mcl.pdf
mcl.pdf
  7525   Thu Oct 11 00:28:30 2012 DenUpdateSUSdiagonalization

I've written MC123 input matrixes to the front-end.

MC1 diagonalization is poor, better then before, but still pitch is seen in pos and yaw. Either smth is malfunctioning or flags touch sensors and do not move freely. On the plot mc1_new black lines - before, red - after rediagonalization.

Attachment 1: mc1_new.pdf
mc1_new.pdf
Attachment 2: mc123_new.pdf
mc123_new.pdf
  7526   Thu Oct 11 01:30:11 2012 DenUpdateSUSdiagonalization

Quote:

MC1 diagonalization is poor, better then before, but still pitch is seen in pos and yaw. Either smth is malfunctioning or flags touch sensors and do not move freely. On the plot mc1_new black lines - before, red - after rediagonalization.

 I've actuated on MC1 with UL, UR, LR, LL coils in turn and measured sensor readings. All coils separately work fine from the first look.

On the plot: black - free mirror, blue - UL coil actuation, green - UR, grey - LR, red - LL.

Attachment 1: mc1_coils.pdf
mc1_coils.pdf
  7530   Thu Oct 11 12:02:15 2012 DenUpdateIOOFSS

FSS SLOW control did not drift during the lock at night with MCL path working and AC coupled.

fss.png

  7532   Thu Oct 11 14:40:20 2012 DenUpdateSUSdiagonalization

Quote:

MC1 diagonalization is poor, better then before, but still pitch is seen in pos and yaw. Either smth is malfunctioning or flags touch sensors and do not move freely. On the plot mc1_new black lines - before, red - after rediagonalization.

 I've manually corrected MC1 input matrix by looking at UL, UR, LL, LR transfer functions between each other. This improved pos significantly and slightly yaw.

Attachment 1: mc1.pdf
mc1.pdf
  7539   Fri Oct 12 22:44:49 2012 DenUpdatePEMETMY table

Quote:

Seismic noise on the ETMY table measured to be a few times higher then on the floor in horizontal direction in the frequency range 50 - 200 Hz. Attached are compared spectrums of X, Y and Z motions.

Accelerometers were installed on the ETMY table and nearby ground to measure amplification of the seismic noise due to the table. During this experiment ground and table motions were measured simultaneously.

DSC_4734.JPG     DSC_4736.JPG

Attachment 1: etmy_x_psd.pdf
etmy_x_psd.pdf
Attachment 2: etmy_y_psd.pdf
etmy_y_psd.pdf
Attachment 3: etmy_z_psd.pdf
etmy_z_psd.pdf
Attachment 4: etmy_coh.pdf
etmy_coh.pdf etmy_coh.pdf etmy_coh.pdf
  7540   Sun Oct 14 11:41:42 2012 DenUpdatePEMETMY table

Quote:

 

Accelerometers were installed on the ETMY table and nearby ground to measure amplification of the seismic noise due to the table. During this experiment ground and table motions were measured simultaneously

 I've added xml file with measurement settings and data to 40m svn at directory 40m_seismic/etmy.

DSC_4739.JPG 

Attachment 2: 14OCT2012.pdf
14OCT2012.pdf 14OCT2012.pdf 14OCT2012.pdf 14OCT2012.pdf
Attachment 3: 14OCT2012.xml
<?xml version="1.0"?>
<!DOCTYPE LIGO_LW [
<!ELEMENT LIGO_LW ((LIGO_LW|Comment|Param|Time|Table|Array|Stream)*)>
<!ATTLIST LIGO_LW Name CDATA #IMPLIED Type CDATA #IMPLIED>
<!ELEMENT Comment (#PCDATA)>
<!ELEMENT Param (#PCDATA)>
<!ATTLIST Param Name CDATA #IMPLIED Type CDATA #IMPLIED Dim CDATA #IMPLIED
                Unit CDATA #IMPLIED>
<!ELEMENT Table (Comment?,Column*,Stream?)>
<!ATTLIST Table Name CDATA #IMPLIED Type CDATA #IMPLIED>
... 231759 more lines ...
  7541   Sun Oct 14 16:44:20 2012 DenUpdatePEMETMX table

 I've measured ETMX table motion compared to ground motion using accelerometers. Data and settings in the xml file are at the svn directory 40m_seismic/etmx.

DSC_4742.jpg

Attachment 2: 14OCT2012.pdf
14OCT2012.pdf 14OCT2012.pdf 14OCT2012.pdf 14OCT2012.pdf
Attachment 3: 14OCT2012.xml
<?xml version="1.0"?>
<!DOCTYPE LIGO_LW [
<!ELEMENT LIGO_LW ((LIGO_LW|Comment|Param|Time|Table|Array|Stream)*)>
<!ATTLIST LIGO_LW Name CDATA #IMPLIED Type CDATA #IMPLIED>
<!ELEMENT Comment (#PCDATA)>
<!ELEMENT Param (#PCDATA)>
<!ATTLIST Param Name CDATA #IMPLIED Type CDATA #IMPLIED Dim CDATA #IMPLIED
                Unit CDATA #IMPLIED>
<!ELEMENT Table (Comment?,Column*,Stream?)>
<!ATTLIST Table Name CDATA #IMPLIED Type CDATA #IMPLIED>
... 231779 more lines ...
  7542   Sun Oct 14 17:26:03 2012 DenUpdatePEMETMX table

Quote:

 I've measured ETMX table motion compared to ground motion using accelerometers. Data and settings in the xml file are at the svn directory 40m_seismic/etmx

 High frequency (>60 Hz) resonances that are present at the ETMX motion spectrum seem to be understandable. Amplification ETMX/GROUND of a factor of 2 at 1 Hz is interesting. I've monitored ACC DQ channels for a few hours and noticed that usually spectrum looks like in the previous elog. But every ~40 min ETMX motion is much higher then ground motion at low frequencies (<5 Hz). I wonder if this a reaction of a table to outside disturbances or accelerometer issue.

 

Attachment 1: etmx.pdf
etmx.pdf etmx.pdf etmx.pdf etmx.pdf
  7543   Sun Oct 14 20:51:20 2012 DenUpdatePEMAA board

Quote:

 

 But every ~40 min ETMX motion is much higher then ground motion at low frequencies (<5 Hz). I wonder if this a reaction of a table to outside disturbances or accelerometer issue. 

 This could come from AA board, its range is +/- 2.5 V, RMS of the ETMX table motion is a few times higher then ground motion, so ETMX accelerometer signal was corrupted.

acc.png

As this small AA range has already caused problems before, I decided to increase it. I've looked through the board scheme and found that all its differential line receives and output amplifiers have absolute maximum range of 40V. We used KEPKO power supply for this board with a voltage range up to 6 V. So I've replaced it with a BK PRECISION power supply and set it to +/- 15 V. Now AA board range is 7.5 V.

DSC_4747.JPG 

I'll leave accelerometers near ETMX table. It's interesting to measure table motion in the morning when trucks drive by.

  7546   Mon Oct 15 10:14:22 2012 DenUpdatePEMAA board

Quote:

 

 I'll leave accelerometers near ETMX table. It's interesting to measure table motion in the morning when trucks drive by.

 That low frequency effect was due to AA board, now it is gone.

  7553   Tue Oct 16 00:08:26 2012 DenUpdateIOOc1lsc DAC0 now connected to tip-tilt SOS DW boards

Quote:

Tomorrow I'll get new SMA cables to connect the DW/AI outputs to the coil driver boards, and I'll start testing the coil driver outputs. 

 I've found a nice 16 twisted pair cable ~25m long and decided to use it as a port from 1Y3 to clean room cable instead of buying a new long one. I've added a break out board to the coil driver end to monitor outputs.

DSC_4748.JPG

  7561   Tue Oct 16 20:40:06 2012 DenUpdateIOOc1lsc DAC0 now connected to tip-tilt SOS DW boards

  Full cable path from coil driver to osem input is now ready. I've tested Ch1-4 of the left AI and left coil driver. 15 pin outputs and monitors show voltage that we expect. I've checked voltage on the other side of the cable in the clean room, it is correct. We are ready to test the coils. We need to bake osem cables asap. Hopefully, Bob will start this job tomorrow.

DSC_4749.JPG DSC_4755.JPG

  7562   Tue Oct 16 21:57:47 2012 DenUpdatePEMaccelerometers

All accelerometers are now at the table behind 1X4, cables are near readout box.

  7565   Wed Oct 17 08:05:10 2012 DenUpdateGeneraldo not leave op-table open

Quote:

ETMX optical table was left open. Burned toast award goes to ......?

 me

ELOG V3.1.3-