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ID Date Author Typedown Category Subject
  4532   Fri Apr 15 13:43:23 2011 BryanConfigurationGreen LockingI leave you with these messages...

Y-end PDH electronics.

The transfer function of the Y-end universal PDH box:



  4536   Fri Apr 15 22:57:38 2011 Aidan, JamieConfigurationLSCAS PD and Camera installed

AS port ITMX YAW  range where AS beam was visible = [-1.505, -1.225] - these extrema put the beam just outside of some aperture in the system -> set ITMX YAW to -1.365

ITMX PITCH range = [-0.7707, -0.9707] -> set to ITMX PITCH to -0.8707


I spent some time tracking down the AS beam which had vanished from the AP table. Eventually, by dramatically mis-aligning SRM, PRM and ITMY, returning BS to its Jan 1st PITCH and YAW values and tweaking the ITMX alignment [actual values to follow], I was able to get an AS beam out onto the AP table. I verified that it was the prompt reflection off ITMX by watching it move as I changed the YAW of that optic and watching it stay stationary as I changed the YAW of ITMY.

Jamie and I then steered the beam through a 2" PLCX-50.8-360.6 lens and placed the RF PD (AS55) at the focus. Additionally, we installed the AS camera to observe the leakage field through a Y1S steering mirror (as shown in the attached diagram).

Currently the PD has power but the RF and DC outputs are not connected to anything at the moment.

Atm 2 by Steve




  4540   Mon Apr 18 17:47:41 2011 kiwamuConfigurationLSCLSC rack's ADC cabling

To understand the situation of the ADC cabling at the LSC rack I looked around the rack and the cables.

The final goal of this investigation is to have nice and noise less cables for the ADCs (i.e. non-ribbon cable)

Here is just a report about the current cabling.


(current configuration)

At the moment there is only one ribbon-twisted cable going from 1Y2 to 1Y3. (We are supposed to have 4 cables).

At the 1Y2 rack the cable is connected to an AA board with a 40 pin female IDC connector.

At the 1Y3 rack the cable is connected to an ADC board with a 37 pin female D-sub connector.

The ribbon cable is 28AWG with 0.05" conductor spacing and has 25 twisted pairs (50 wires).



(things to be done)

 - searching for a twisted-shielded cable which can nicely fits to the 40 pin IDC and 37 pin D-sub connectors.

 - estimating how long cable we need and getting the quote from a vendor.

 - designing a strain relief support

  4541   Mon Apr 18 21:09:45 2011 JamieConfigurationComputersnew control room machine: pianosa

I've just installed the new control room machine: "pianosa".   It is a replacement for the old sun machine "op440m" [0].


  • dual dual-core Intel Core i7-2600 CPU @ 3.40GH, hyperthreaded to provide 8 effective cores
  • 16G memory (4x 4G dimms)
  • nVidia GF108 GeForce GT 430

It's now running Ubuntu 10.04 LTS 64bit.  Unfortunately, the default 10.04 kernel is 2.6.32, which does not support pianosa's apparently very new network adapter, which is (from lspci):

00:19.0 Ethernet controller: Intel Corporation 82579LM Gigabit Network Connection (rev 04)

To get around this I temporarily added a PCI nic so that I could get on the network.  I then added the Ubuntu kernel team PPA archive and installed linux-image-2.6.38-2, which is new enough to have the needed network driver, but not completely bleeding edge:

sudo add-apt-repository ppa:kernel-ppa/ppa
sudo apt-get update
sudo apt-get install linux-image-2.6.38-2-generic linux-headers-2.6.38-2-generic

Once the built in nic was working I removed the temporary one.  Everything seems to be working fine now.

I have not yet done any configuration to integrate pianosa into the CDS network.  I'll do that tomorrow.

[0] op44m has been moved into the control room rack next to linux1, in headless mode.  If there is still a need to run scripts that only run on solaris, op440m can still be accessed via ssh as normal.  Hopefully we can fully decommission this machine soon.

[1] https://launchpad.net/~kernel-ppa/+archive/ppa

  4542   Mon Apr 18 21:14:53 2011 JamieConfigurationComputersnew control room machine: pianosa
Also, op440m's Sun monitor did not work well with pianosa, so I'm lending pianosa my HP monitor until we can get a suitable replacement.
  4547   Wed Apr 20 21:53:01 2011 SureshConfigurationRF SystemRF system: Stray heliax cable

We found a stray unused heliax cable running from the LSC rack 1Y2 to a point between the cabinets 1X3 and 1X4. This cable will need to be redirected to the AS table in the new scheme.   It is labled C1LSC-PD5  The current situation has been updated as seen in the layout below


Attachment 1: rogue_cable_1.png
  4603   Tue May 3 00:44:02 2011 KojiConfigurationComputersMartian WIreless Bridge

The Martian wireless bridge has the ethernet cable inserted in the wrong connector.

It should be inserted to one of the four port. Not in the "INTERNET" connector.

Once the connector has been changed, the martian net as well as the internet became accessible from the laptops.

  4612   Tue May 3 14:35:44 2011 Larisa ThorneConfigurationElectronicsJenne-Seismometer LPF project

 I was charge with making a Non-Inverting Op Amp Low Pass Feedback circuit for Jenne, which may somehow be integrated into a seismometer project she's working on.


Circuit diagram is attached. Calculations show that R1, R2 and C have the following relationship: if R1=10^n, R2=10^(n+1), C=10^(-n-4). For the particular circuit being modeled by the transfer function, R1=100 Ohm, R2=1k Ohm, and C=1uF.

Attached also is the circuit's Bode plot, showing frequency versus gain and phase, respectively. The frequency versus gain graph is true to what the circuit was calculated to generate: a gain of +20 and a cutoff frequency at 200Hz. Not sure what's going on with the frequency verus phase plot.

Attachment 1: SeisLPFdiagram.jpg
Attachment 2: seisLPF.Bose.jpg
  4625   Wed May 4 13:51:51 2011 valeraConfiguration Intermittent MC3 UL PD signal

The attached plot shows the 30 day trend of the MC3 UL PD signal. The signal dropped to zero at some point but now it is close to the level it was a few weeks ago. There still could be a problem with the cable.

The rest of the MC1,2,3 PD signals looked ok.

Attachment 1: mc3ulpdmon.pdf
  4630   Wed May 4 17:32:06 2011 Larisa ThorneConfigurationElectronicsJenne-Seismometer LPF project

Building on what was posted previously



The configuration has now evolved into an Inverting Op Amp Feedback Low Pass Filter circuit.

Had to change out some components to satisfy conditions: R1=1k Ohm, R2=10k Ohm, C=0.1uF. These were changed in order to decrease the magnitude of the current passing through the op amp by a factor of 10 (10V supplied through the R1 resistor yields about 10mA). The configuration itself was changed from non-inverting to inverting in order to get the frequency vs. gain part of the Bode plot to continue to decrease across higher frequencies instead of leveling off around 4kHz.

Attachment 1: SeisLPF3.jpg
  4634   Thu May 5 12:01:53 2011 Larisa ThorneConfigurationElectronicsJenne-Seismometer LPF project

 Having finished the bulk of the work for the LPF itself ( see here ), I have begun trying to design the seismometer box to Jenne's specifications.


Currently looking into what the voltage buffer amplifier might look like for this.



Suggestions/corrections would be much appreciated!



Attachment 1: STS2diagram.png
  4642   Thu May 5 15:26:52 2011 Leo SingerConfigurationComputers'glue' installed on some control room computers

I installed 'glue' on Rossa, Allegra, and Rosalba.  This is a Python module that includes a facility for LIGO_LW XML files.  Oddly, I couldn't find the glue package on Pianosa.

  4644   Thu May 5 15:33:37 2011 steveConfigurationRF SystemLSC rack

New right angle PVC front panel with SMA bulkhead connectors are in place. The connections are still lose. It is ready for Suresh to finalise his vision on it.

Attachment 1: P1070641.JPG
Attachment 2: P1070639.JPG
  4646   Thu May 5 17:19:21 2011 Leo SingerConfigurationSUSTuning notch filters for bounce mode suspensions

I am tuning the notch filters for the bounce modes in the suspensions, starting with the ITMs and ETMs.  I'll do the MCs, the PRMs, and the SRMs next.


I noticed that the filter for ITMX (in the file C1SUS.txt, the module ITMX_SUSPOS, the selection BounceRoll) that the filter was composed of two bandstops (and a constant gain).  It looked like this:




Valera said that one of these was for the roll mode and the other for the bounce mode.  However, looking at the spectra that Kiwamu and I made this week, I don't perceive a resonance between 11.4 and 12.2 Hz.  So, we're taking a guess that this was for a mode that has moved due to new pendulum designs.  For many of the suspensions, in the free swinging test we noticed a line around 23 Hz; we thought we might as well re-use one of these elliptical filters to avoid exciting this line.  Of course, if this line does *not* result from excitation of an uncontrolled degree of freedom, this will not help and could be detrimental.  When we talk to Valera again, we can review this decision and at that point we might decide just to take out that bandstop.


ITMX is done.  I'll continue tomorrow.  I've attached closed-loop spectra for before the tuning (itmx-before.pdf) and after (itmx-after.pdf).


(Update: the following day, I took closed loop spectra with (itmx-withbounceroll.pdf) and without (itmx-nobounceroll.pdf) the bandstops.  It looks like the bandstops made the bounce mode slightly worse, but the roll mode slightly better.)



Attachment 1: itmx-before.pdf
Attachment 2: itmx-before.pdf
Attachment 3: itmx-withbounceroll.pdf
Attachment 4: timx-nobounceroll.pdf
  4652   Fri May 6 14:59:36 2011 Leo SingerConfigurationSUSTuning ITMY bandstop

I tuned the ITMY bandstops -- 'before' and 'after' spectra attached.  Note that the after the tuning, the bounce mode at ~16 Hz is about twice as quiet!


However, notice that in the 'before' plot the roll mode at about 23.5 Hz did not show up at all, whereas it is quite prominent in the 'after' plot.  I was concerned that this line could have been a result of placing the bandstop there, so I made another plot with the BounceRoll filter turned off.  Sure enough, the 23.5 Hz line is still there.  So I'm not crazy: the roll mode did start acting up at some time between my 'before' and 'after' plot, but not as a result of the tuning.

Attachment 1: itmy-before.pdf
Attachment 2: itmy-after.pdf
Attachment 3: itmy-nobounceroll.pdf
  4667   Mon May 9 16:12:49 2011 JamieConfigurationCDScanonicalize paths to core and userapps

I have updated the /opt/rtcds paths to reflect the new specification of the CDS aLIGO code release procedures document.

Path to RTS/opt/rtcds/caltech/c1/core/release

This is where the advLigoRTS front-end code generator is checked out.  The "release" directory is a link to the svn branch from which we are currently running ("trunk" by default).

This used to be at /opt/rtcds/caltech/c1/core/advLigoRTS

Path to userapps: /opt/rtcds/caltech/c1/userapps/release

This is where the cds_user_apps code is checked out.  cds_user_apps is where all of the front-end models, medm screen, scripts, etc. will live.  The "release" directory is a link to the svn branch from which we are currently running ("trunk" by default).

This was most recently at /opt/rtcds/cds_user_apps


  4685   Wed May 11 10:49:16 2011 valeraConfigurationElectronicsMC3 LL PD has no signal

Yesterday we found that MC3 OSEM LL PD did not have a sensible signal - the readback was close to zero and it was making MC move around. I disabled the PD LL so that the damping is done with just three face plus side PDs. There still no signal from MC3 LL PD today. It needs debugging.

  4690   Wed May 11 16:04:36 2011 Larisa ThorneConfigurationElectronicsJenne-Seismometer LPF project

The schematic for the seismometer box from this last time  has been updated...


Koji was helpful for coming up with a general diagram for the voltage buffer amplifier, which has now been added to the configuration pictured below.

The only thing that remains now before I try to plot it with Eagle/LISO is to pick an op amp to use for the voltage buffer itself. Someone suggested THS4131 for that (upon Googling, it hit as a "high speed, low noise, fully-differential I/O amplifier"). It looks good, but is it the best option?

Attachment 1: STS2diagram2.png
  4691   Wed May 11 17:10:04 2011 kiwamuConfigurationElectronicsfixed : MC3 LL PD has no signal

[Valera / Kiwamu]

It was because of a loose connection. Pushing the connector solved the issue.


We really have to think about making reliable connections and strain reliefs.

Quote from #4685

Yesterday we found that MC3 OSEM LL PD did not have a sensible signal - the readback was close to zero and it was making MC move around. I disabled the PD LL so that the damping is done with just three face plus side PDs. There still no signal from MC3 LL PD today. It needs debugging.


  4692   Wed May 11 17:20:24 2011 kiwamuConfigurationIOOloop diabled on PZT2

[Valera / Kiwamu]

The pointing of the incident beam to the interferometer has been jumping frequently.

Due to this jump the lock of the Y arm didn't stay for more than 2 min.

We turned off the strain gauge loop of PZT2-YAW and PZT2-PITCH, then the spot motion became solid and the Y arm locking became much more robust.

  4713   Fri May 13 17:20:48 2011 Leo SingerConfigurationSUSTuned bounce and roll mode of ETMY suspension

I tuned the bounce and roll mode bandstops for ETMY, although it was difficult for me to tell if there was improvement with the bandstops on relative to the bandstops off because it seemed like the bounce and roll modes were being excited intermittently.  I'll take spectra with the filters both on and off during an evening next week.

  4730   Tue May 17 11:45:20 2011 JamieConfigurationCDSpurged non-c1 site files from rtcds checkout of cds_user_apps
I purged all of the working copy checkouts of site files for all sites that are not c1 from the rtcds cds_user_apps working directory (/opt/rtcds/caltech/c1/userapps/trunk). I first checked that there were no outstanding changes, and then did the following (in bash):
cd /opt/rtcds/caltech/c1/userapps
rm -rf trunk
svn update --depth=files trunk
svn update --depth=empty trunk/{CDS,ISI,ISC,PSL,SUS}
svn update trunk/{CDS,ISI,ISC,PSL,SUS}/{c1,common}
  4732   Tue May 17 17:01:22 2011 jamieConfigurationCDSUpdate LSC channels from _DAQ to _DQ

As of RCG version 2.1, recorded channels use the suffix "_DQ", instead of "_DAQ".  I just rebuilt and installed the c1lsc model, which changed the channel names, therefore hosing the old daq channel ini file.  Here's what I did, and how I fixed it:

$ ssh c1lsc
$ cd /opt/rtcds/caltech/c1/core/trunk
$ make c1lsc
$ make install-c1lsc
$ cd /opt/rtcds/caltech/c1/scripts
$ ./startc1lsc
$ cd /opt/rtcds/caltech/c1/chans/daq
$ cat archive/C1LSC_110517_152411.ini | sed "s/_DAQ/_DQ/g" >C1LSC.ini
$ telnet fb 8087
daqd> shutdown


  4733   Tue May 17 18:09:13 2011 Jamie, KiwamuConfigurationCDSc1sus and c1auxey crashed, rebooted

c1sus and c1auxey crashed, required hard reboot

For some reason, we found that c1sus and c1auxey were completely unresponsive.  We went out and gave them a hard reset, which brought them back up with no problems.

This appears to be related to a very similar problem report by Kiwamu just a couple of days ago, where c1lsc crashed after editing the C1LSC.ini and restarting the daqd process, which is exactly what I just did (see my previous log).  What could be causing this?

  4735   Tue May 17 22:50:00 2011 JamieConfigurationLSCNew digital lockin added to LSC model/screen

I added a lockin to the LSC model, and added it's corresponding control to the LSC screen.  Here's is what I added to the LSC model:


On the left are the froms from the normalized RF PD outputs. Those go into a matrix, whose single row goes into the lockin signal input. The clock output from the lockin goes into the LSC output matrix (last row).

Here is what I added to the LSC master screen:


I also modified the lockin overview screen:


I think this new screen looks a lot cleaner.  Maybe we could start using this one as a template for lockin screens.

  4743   Wed May 18 22:11:31 2011 ranaConfigurationLSCNew digital lockin added to LSC model/screen


 This is OK....but, the input matrix should come from the same place as the regular input matrix: i.e. it should be just another row like CARM, DARM, etc. rather than have its own screen.

Also, I think a nice mod to all the matrices would be if the ORANGE triangle was only visible when there's a signal flowing through it.

  4761   Mon May 23 14:28:23 2011 kiwamuConfigurationLSCPOY55 installed

Last Saturday the POY55 RFPD (see this entry) was installed on the ITMY optical bench for the trial of the DRMI locking.

Since the amount of the light coming into the diode is tiny, the DC monitor showed ~ 3 mV even when the PRC was locked to the carrier.

In order to amplify the tiny RF signal from the photo diode a ZHL amplifier was installed next to the RFPD. The RF amp is sitting on delrin posts for insulation from the table.


  4763   Mon May 23 18:16:42 2011 KojiConfigurationLSCPOY55 installed

The DC Transimpedance of POP55 was increased from 50 Ohm to 10010 Ohm. There is the offset of 46mV. This should be cancelled in the CDS.


Last Saturday the POY55 RFPD (see this entry) was installed on the ITMY optical bench for the trial of the DRMI locking.

Since the amount of the light coming into the diode is tiny, the DC monitor showed ~ 3 mV even when the PRC was locked to the carrier.

In order to amplify the tiny RF signal from the photo diode a ZHL amplifier was installed next to the RFPD. The RF amp is sitting on delrin posts for insulation from the table.


  4764   Wed May 25 19:03:59 2011 JamieConfigurationCDSUpdate rtcds checkout of cds_user_apps with new top-level directory names.

The top-level subsystem subdirectories in the cds_user_apps source repository were renamed today to be all lower case.  This required checking out the new directory and updating all of the model links in /opt/rtcds/caltech/c1.  Here is how I updated the cds_user_apps working tree:

cd /opt/rtcds/caltech/c1/userapps
mv trunk{,.bak}
svn update --depth=files trunk
svn update --depth=empty trunk/{cds,isi,isc,psl,sus}

I then fixed the links in the /opt/rtcds/caltech/c1/core/release/src/epics/simLink directory:

for link in $(find . -maxdepth 1 -type l); do ln -sf $(readlink $link | tr [:upper:] [:lower:]) ; done

A couple of things had to be cleaned up:

  • /opt/rtcds/caltech/c1/userapps/trunk/cds/c1/models/c1uct.mdl was linked in, but that model doesn't seem to exist anymore, so I removed the link.
  • a couple of things were linked from /opt/rtcds/caltech/c1/userapps/trunk instead of /opt/rtcds/caltech/c1/userapps/release, so I fixed those links.
  • /opt/rtcds/caltech/c1/userapps/release/cds/test/models/llo/l1isctest.mdl was not checked out, so I checked it out and fixed the link (this model should really be named something different if it is of common use, or we plan on using it at the 40m).


  4765   Wed May 25 19:19:11 2011 JamieConfigurationCDS!!!CHECK IN YOUR MODELS!!!


Today I found three models that were modified, but not checked in to the SVN repository:

M       sus/c1/models/lib/sus_single.mdl
M       isc/c1/models/c1lsc.mdl
M       isc/c1/models/c1mcp.mdl

I checked in the c1lsc model, since I think it was just the change that Kiwamu made in http://nodus.ligo.caltech.edu:8080/40m/4749.  I left the others, since I have no idea what they are or who made them.

Please please please remember to commit your model changes to the SVN after you're done.  This is particularly important for important models, such as c1lsc.  If you don't check in your changes I can pretty much guarantee that at some point you will loose them.


  4766   Wed May 25 20:12:55 2011 JamieConfigurationLSCNew digital lockin added to LSC model/screen


This is OK....but, the input matrix should come from the same place as the regular input matrix: i.e. it should be just another row like CARM, DARM, etc. rather than have its own screen.

 You're absolutely right.  That was a brain-fart oversight.  I fixed the model so that the input from the lockin comes from another output row in the RFPD input matrix.  I then fixed the C1LSC medm screen accordingly:


This is obviously much simpler and more straight-forward.

A future improvement would be to modify the DCPD input matrix to be able to route those signals to the lockin as well.  This is actually currently possible since the DCPD input matrix is just a subset of the full input matrix, but it's not available via medm yet.

  4767   Thu May 26 17:10:21 2011 JamieConfigurationLSCNew digital lockin added to LSC model/screen


A future improvement would be to modify the DCPD input matrix to be able to route those signals to the lockin as well.  This is actually currently possible since the DCPD input matrix is just a subset of the full input matrix, but it's not available via medm yet.

 I went ahead and added the lockin output to the DCPD input matrix.


  4774   Tue May 31 16:07:57 2011 Larisa ThorneConfigurationElectronicsSeismometer Box Update

 (Continuation of this)


I plugged the circuit into the LISO program to generate the graphs below....the first graph is a plot of frequency (f, in Hz) versus gain (in dB), and frequency (f, Hz) versus phase (in degrees). Also included is the second graph, which is a noise plot of all circuit parts which contribute to the total noise of the circuit.


The only issue I had was that two of the op amps I'd picked (see third attachment for the original circuit diagram) for the circuit were not in LISO's op amp library. So I replaced THS4131 (from the voltage buffer part) and AD826 (from the ADC driver part) with AD797 and LT1037, respectively in order to generate the plots below....   


There are notes calling the AD797 "ultra low noise, low distortion", whose data sheet can be found here: AD797 

Notes also call LT1037 "low noise, high speed precision op amp", whose data sheet can be found here: LT1037


I've put these in temporarily only, as I don't know if they are appropriate choices for the job or even if we have them. Suggestions?

Attachment 1: SeisBoxLISOplot1.pdf
Attachment 2: SeisBoxLISOplot2.pdf
Attachment 3: STS2diagram_original.pdf
  4788   Mon Jun 6 17:22:09 2011 valeraConfigurationLSCClipping in the X arm 1064 um trans path

I changed optics in the ETMX transmon path to remove clipping (which made a false QPD signal).

During the weekend I found that there was an offset in X arm c1ass pitch servo, which derives the signal by demodulating the arm cavity power, coming from the beam clipping in the transmon path.

The clipping was on the pair of the 1" mirrors that steer the beam after the 2" lens (see attached picture). The beam is about 5-6 mm in diameter at this distance from the lens and was not well centered.

I moved the steering mirrors downstream by about 8" where the beam is about 2-3 mm (the attached picture shows the mirrors in the new location). The Y arm layout is different from X arm and I didn't find any obvious clipping in transmon path.

The max X arm buildup went up from 1.3 to 1.5. I changed the TRX gain from -0.003 to -0.002 to obtain the normalized X arm power of 1 in this state. The MC refl DC is 1.6 out of 4.9 V and the Y arm buildup is ~0.9 so the TRX(Y) gains will have to be adjusted once the MC visibility is maximized.

Attachment 1: XarmTransMon.pdf
  4792   Mon Jun 6 23:56:16 2011 rana, valeraConfigurationSUSETMX/ETMY OSEM whitening

 We measured the OSEM PD whitening transfer function of the ETMX OSEM UL whitening stage (D000210) by comparing the input signal to the whitening amplifier (single pin LEMO monitor) to the output signal - both were piped into the DAQ. The transfer function was close to constant 0 dB/180 deg independent of the whitening switch selection (FM1 filter engaged/disengaged)  up to ~20 Hz where we run out of coherence. All other ETMX and ETMY spectra at the input of the digital whitening compensation don't change when the whitening is switched on/off so by induction we conclude that all the ETMX/ETMY OSEM PD hardware whitening filters are not on.

  4812   Mon Jun 13 19:26:42 2011 Jamie, JoeConfigurationCDSSUS binary IO chassis 2 and 3 moved from 1X5 to 1X4

While preping 1X4 for installation of c1lsc, we removed some old VME crates that were no longer in use.  This freed up lots of space in 1X4.  We then moved the SUS binary IO chassis 2 and 3, which plug into the 1X4 cross-connect, from 1X5 into the newly freed space in 1X4.  This makes the cable run from these modules to the cross connect much cleaner.

  4814   Tue Jun 14 09:24:36 2011 steveConfigurationPhotosSUS binary IO chassis 2 and 3 moved from 1X5 to 1X4


While preping 1X4 for installation of c1lsc, we removed some old VME crates that were no longer in use.  This freed up lots of space in 1X4.  We then moved the SUS binary IO chassis 2 and 3, which plug into the 1X4 cross-connect, from 1X5 into the newly freed space in 1X4.  This makes the cable run from these modules to the cross connect much cleaner.

 Are we keeping these?

Attachment 1: P1070891.JPG
Attachment 2: P1070893.JPG
  4830   Fri Jun 17 00:17:26 2011 ranaConfigurationElectronics2 RFPDs sent to LLO

Koji and I found 2 RFPD boxes to send to LLO. We've put them onto Steve's desk to be overnighted to Valera.

One of them is our old 21.5 MHz gold box RFPD from the FSS (which we don't use). The other one is a 2mm gold box one which was previously tuned for 66 MHz.


They shipped out on Friday

Attachment 1: P1070895.JPG
  4881   Fri Jun 24 22:35:23 2011 ranaConfigurationCDSdataviewer broken on pianosa

When I try to get minute trend, it says "word too long".

  4926   Thu Jun 30 21:55:16 2011 ranaConfigurationDAQNDS2 conf change

As I recently had trouble getting all of the SUS SENSOR channels at once from NDS2, I asked J.Z. for help. He found that the number of buffers on mafalda was set to only allow a small amount of data to be requested at one time.

He's going to have to figure out a more permanent fix, but for now he's increased the data buffer size to allow somewhat larger chunks to be gotten. I have made a work around in matlab, which gets smaller chunks and then cats them together.

Its in SUS/peakFit/.

Attachment 1: Untitled.png
  4959   Mon Jul 11 10:10:31 2011 IshwitaConfiguration AA board

The AA board shown in attachment 1 will be used in the seismometer hardware setup. A cartoon of this setup is shown in attachment 2.

BNC connectors are required for the seismometer breakout boxes. So the four-pin LEMO connectors present in the AA board were removed and panel mount BNC connectors were soldered to it. Red and blue colored wires were used to connect the BNC connectors to the board. Red wire connects the center of the BNC connector to a point on the board and that connection leads to the third leg (+IN) of the IC U### and the blue wire connects the shield of the BNC connector to the second leg (-IN) of the IC U###.

All the connections (including BNC to the AA board and in the AA board to all the filters) were tested using a multimeter by the beeping method and it was found that channel 10 (marked as C10) had a wrong connection from the point where the red wire (+ve) was connected to the third leg (+IN) of IC U91  and channel 32 (marked as C32) had opposite connections meaning the blue wire is connected to the third leg (+IN) of IC U311 and red wire is connected to the second leg (-IN) of IC U311.

Attachment 1: P7080305.JPG
Attachment 2: seismometers.png
  4979   Sat Jul 16 18:54:05 2011 Ishwita, ManuelConfigurationElectronicsAA board

We fixed the anti-aliasing board in its aluminum black box,  the box couldn't be covered entirely because of the outgoing wires of the BNC connectors, so we drilled additional holes on the top cover to slide it backwards by 1cm and then screw it.

We had to fix the AA board box in rack 1X7, but there wasn't enough space, so we tried to move the blue chassis (ligo electro-optical fanout chassis 1X7) up with the help of a jack. We removed the blue chassis' screws but we couldn't move it up because of a piece of metal screwed above the blue chassis, then we weren't able to screw the two bottom screws again anymore because it had slided a bit down. Thus, the blue chassis (LIGO ELECTRO-OPTICAL FANOUT CHASSIS 1X7) is still not fixed properly and is sitting on the jack.

To accommodate the AA board (along with the panel-mounted BNC connectors) in rack 1X7 we removed the sliding tray (which was above the CPU) and fixed it there. Now the sliding tray is under the drill press.


Attachment 1: DSC_3236.JPG
Attachment 2: pic1.png
Attachment 3: DSC_3237.JPG
  5049   Wed Jul 27 15:49:13 2011 jamieConfigurationCDSdataviewer now working on pianosa

Not exactly sure what the problem was, but I updated to the head of the SVN and rebuilt and it seems to be working fine now.

  5210   Fri Aug 12 16:42:51 2011 YoichiConfigurationLSCLSC Feed Forward Compensator
I've been working on adding feed forward (FF) paths to our LSC code.
So far, I've made a basic feed forward functionality connected
to the feedback path of the LSC model.

As is shown in the MEDM screen, this feed forward compensator (FFC)
takes feedback signals from several DOFs (MICH, PRCL, SRCL, CARM, XARM and YARM)
and put those signals through some filters. Then the filtered signals are
summed into the feedback signals.

There are input and output matrices to select which signal goes to which signal.

Usually, we just want to feed forward MICH to DARM. We may also want to do PRCL
to DARM and SRCL to DARM if necessary.
It is more unlikely that we use CARM for FF. But I put it there just in case.
XARM and YARM will not going to be used as is. These are place holders for future
experiments, like low frequency FF from seismic channels or something like that.
Feed forward is almost always done to DARM. But just in case we want to do some
fancier FF, like FF from PRCL to MICH, the output matrix is there to chose where
the signals will go.

I haven't really tested it because we don't have the interferometer working.
But I checked the signal flow, and it seems the model is working correctly.

=== Implementation ===
FFC is running in a separate realtime code, called c1ffc.
This is to offload c1lsc from the possible intense calculations, like adaptive stuff,
performed in the FFC in the future.
The LSC signal is passed to c1ffc via shared memory. The calculated FF signals
are passed back to c1lsc via shared memory too.
Even though FFC is in a separate realtime model, it is still conceptually a part of LSC.
So, I used top_names tag to change the names of the channels to C1:LSC-FFC_* instead of

In MEDM, there is an "ENABLE" button in the FF screen. Even though it is shown in the FFC
overview screen, the button itself is in the c1lsc code, so that we can disable the FFC
even when c1ffc is dead or going crazy.

=== Background ideas ===
For those of you wondering what is this feed forward thing for, I will put a brief explanation here.
Taking MICH as an example, we get the error signal for MICH from probably REFL_55Q (or AS_55Q ?).
At low frequencies, this signal properly reflects the motion of the mirrors (mostly seismic).
However, it has much worse shot noise than DARM. At higher frequencies, like above a few tens of Hz,
the error signal is dominated by the shot noise. Feeding back this signal to, say BS, means
we are shaking the BS by the shot noise, which was otherwise quiet at high frequencies.

Now, if the BS is shaken, it has some intrinsic coupling to the DARM signal.
The mechanism is that the BS motion creates some audio frequency sidebands
and this SBs reach the AS port and beat against the local oscillator to create
fake GW signals. This is called "Loop Noise Coupling".

A well known way to mitigate this problem is feed forward.
Since we know how much we are shaking the BS (because we are doing it), and
we can measure the amount of BS to DARM coupling, we can subtract out the
loop noise by feeding forward the MICH feedback signal to the DARM actuators.
In other words, the noise SBs created at the BS is canceled on the PD by the
extra SBs created at the ETMs by the feed forward.

This is what FFC is trying to do.
Attachment 1: FFCinLSC.png
Attachment 2: FFC.png
  5211   Fri Aug 12 16:50:37 2011 YoichiConfigurationCDSFE Status screen rearranged
I rearranged the FE_STATUS.adl so that I have a space to add c1ffc in the screen.
So, please be aware that the FE monitors are no longer in their original positions
in the screen.
  5213   Fri Aug 12 17:05:22 2011 Manuel, IshwitaConfigurationPEMSTS2 Cable configuration

The WWF_M connector is the end of the STS2 seismometer orange cable and the S1 connector is the end of the gray 26-pin-cable


  5278   Mon Aug 22 20:37:43 2011 AnamariaConfigurationRF SystemPlan for install of 3f PDs

I made a quick sketch of how to include two more RF PDs on the REFL beam, given the space we have on the table. We want to install REFL33 and REFL165, 3f signals for the the two modulation frequencies we are using. The point is to make the distance from first beam splitter the same to all PDs so that we can use only one lens before this BS to make the beam the right size. Currently there are 2 PDs on the refl beam, REFL11 and REFL55, predictably. So the drawing shows 4 PDs. Drawing is to scale but is a bit coarse. Hopefully we'll take pictures once we're done.

Reference from current BS splitting beam to the existing PDs.

Attachment 1: 40m3fReflPdLayout.pdf
  5318   Mon Aug 29 16:27:34 2011 ManuelConfigurationSUSSUS Summary Screen

I edited the C1SUS_SUMMARY.adl file and set the channels in alarm mode to show the values in green, yellow and red according to the values of the thresholds (LOLO, LOW, HIGH, HIHI)

I wrote a script in python, which call the command ezcawrite and ezcaread, to change the thresholds one by one.

You can call this program with a button named "Change Thresholds one by one" in the menu come down when you click the  button.

I'm going to write another program to change the thresholds all together.

  5389   Mon Sep 12 18:45:04 2011 AnamariaConfigurationLSCAP table current layout

Before we install the REFL 3f PDs I made a drawing of the current table layout, since there has been no update lately. Once I've incorporated the two extra PDs (now seen sitting bottom left), I will update the drawing and post in the wiki as well.

Attachment 1: 40mAPtable.pdf
  5390   Mon Sep 12 23:45:14 2011 SureshConfigurationComputer Scripts / ProgramsStripTool does not scale properly on Pianosa

When I run StripTool on Pianosa, I get the following message

==== StripTool Xt Warning Handler ====
warning:         Axis: minVal is greater than or equal to maxVal


And the y-axis scale reverts to 0 -100 regardless of what ever I set in the controls panel

I ssh'ed into rosalba and ran striptool from there and did not face this problem.  So I think pianosa has a problem with Striptool.

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