40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 141 of 344  Not logged in ELOG logo
ID Date Author Type Category Subjectup
  13014   Thu May 25 18:37:11 2017 jigyasaUpdateComputer Scripts / ProgramsMaking pylon installation on shared directory

Gautam helped me execute the commands mentioned above and Pylon has now been installed on the shared directory. We extracted the pylon installation from Johannes's directory to the shared drive and executing the command tar –C /opt/rtcds/caltech/c1/scripts/GigE –xzf pylon SDK*.tar.gz created an unzipped pylon5 folder in /scripts. The ./setup-usb.sh set up the udev rules for the GigE.

The installation took place without any errors.

The Pylon viewer app can now be accessed at /opt/rtcds/caltech/c1/scripts/GigE/pylon5/bin followed by ./PylonViewerApp 


Should I go ahead with the installation in the shared directory?


  976   Mon Sep 22 15:02:45 2008 ranaFrogsTreasureMantis found outside the 40m door at night
  5034   Mon Jul 25 23:43:20 2011 ManuelHowToElectronicsManual for 1201 Low Noise Preamplifier

I found the manual for the Low Noise Preamplifier Model 1201 at this link and I attached it.

The one we have in the lab (S/N 48332) miss the battery packs and miss also the remote programming options input/output. Its inside battery compartment is empty and I found 2 unscrewed screws with washers and nuts inside the preamplifier box. The battery cable are disconnected and they have 2 green tape labels (-) and 2 red tape label (+).



  14395   Thu Jan 10 11:32:40 2019 ChubUpdateVACManual valve interfaced with CDS

Connected the manual gate valve status indicator to the Acromag box this morning.  Labeled the temporary cable (a 50' 9p DSUB, will order a proper sized cable shortly) and the panel RV2.  

  5050   Wed Jul 27 15:49:56 2011 steveUpdateSAFETYManuel receives safety training

Our surf student Manuel Marchiò received 40m specific safety training today.

  15743   Mon Dec 21 18:18:03 2020 gautamUpdateCDSMany model changes

The CDS model change required to get the AS WFS signals into the RTCDS system are rather invasive.

  • We use VCS for these models. Linus Torvald may question my taste but I also made local backups of the models, just in case...
  • Particularly, the ADC1 card on c1ioo is completely reconfigured.
  • I also think it's more natural to do all the ASC computations on this machine rather than the c1lsc machine (it is currently done in the c1ass model). So there are many IPC changes as well.
  • I have documented everything carefully, and the compile/install went smoothly.
  • Taking down all the FE servers at 1830 local time
    1. To propagagte the model changes
    2. To make a hardware change in the c1rfm card in the c1ioo machine to configure it as "ROGUE MASTER 0"
    3. To clear the RFM errors we are currently suffering from will require a model reboot anyways.
  • Recovery was completed by 1930 - the RFM errors are also cleared, and now we have a "ROGUE MASTER 👾" on the network. Pretty smooth, no major issues with the CDS part of the procedure to report.
  • The main issue is that in the AA chassis I built, Ch14 (with the first channel as Ch1) has the output saturated to 28V (differential). I'm not sure what kind of overvoltage protection the ADC has - we frequently have the inputs exceed the spec'd +/-20 V (e.g. when the whitening filters are engaged and the cavity is fringing), but pending further investigation, I am removing the SCSI connection from the rear of the AA chassis.

In terms of computational load, the c1ioo model seems to be able to handle the extra load no issues - ~35us/60us per cycle. The RFM model shows no extra computational time

After this work, the IMC locking and POX/POY locking, and dither alignment servos are working okay. So I have some confidence that my invasive work hasn't completely destroyed everything. There is some hardware around the rear of 1X2 that I will clear tomorrow.

  11479   Wed Aug 5 10:56:07 2015 ericqUpdateCDSMany models crashed

Last night around 1AM, many of the the frontend models crashed due to an ADC timeout. (But none of the IOPs, and all the c1lsc models were fine.)

First, on c1sus (Wed Aug  5 00:56:46 PDT 2015)
[1502036.695639] c1rfm: ADC TIMEOUT 0 46281 9 46153
[1502036.945259] c1pem: ADC TIMEOUT 0 56631 55 56695
[1502036.965969] c1mcs: ADC TIMEOUT 1 56706 2 56770
[1502036.965971] c1sus: ADC TIMEOUT 1 56706 2 56770

Then, simultaneously on c1ioo, c1iscex, and c1iscey. (Wed Aug  5 01:10:53 PDT 2015)

[1509007.391124] c1ioo: ADC TIMEOUT 0 46329 57 46201
[1509007.702792] c1als: ADC TIMEOUT 1 63128 24 63192

[2448096.252002] c1scx: ADC TIMEOUT 0 46293 21 46165
[2448096.258001] c1asx: ADC TIMEOUT 0 46669 13 46541

[1674945.583003] c1scy: ADC TIMEOUT 0 46297 25 46169
[1674945.685002] c1tst: ADC TIMEOUT 0 52993 1 52865

I'm still working on getting things back up and running. Just restarting models wasn't working, so I'm trying some soft reboots...

UPDATE: A soft reboot of all frontends seems to have worked,

  6904   Mon Jul 2 18:28:09 2012 JenneUpdatePhotosMany photos taken

Many photos were taken by many different people....most of the fuzzy ones are by yours truely (doing a reach-around to get to hard-to-reach places), so sorry about that.

I put all the photos from yesterday and today into 6 new albums on Picasa:  https://picasaweb.google.com/foteee

The album titles are generally descriptive, and I threw in a few comments where it seemed prudent.

Big note:  The tip tilt on the ITMX table does, in fact, have the arrow pointing in the correct direction.  Photo is in the TT album from today.

  15011   Mon Nov 4 19:02:25 2019 YehonathanUpdatePSLMapping the PSL electronics

I created a spreadsheet (Attached) by taking Koji's c1psl sheet from slow_channel_list and filtering out the channels that do not need an Acromag. I added in the QPD channels that are relevant to the PSL from the c1iool0 sheet.

I began mapping the PSL related Eurocrates connectors to their respective VME channels starting with the PMC electronics.

I am confused about the TTFSS interface (D040423): While it is a Eurocrate card, in the schematics it seems to have 50 pin connectors.

I found old wiring schematics that might help with identifying the channels once the connector issue is clarified.



  15099   Tue Dec 17 00:23:28 2019 YehonathanUpdatePSLMapping the PSL electronics

I added to the PSL wiring list the ioo channels and the laser shutter (See attached pdf for an updated list).

The total channel numbers for now:

ai 57
ao 13
bi 1
bo 36

I counted each mbbo as 1 bo but I am not sure that's correct.

Still need to allocate Acromags.

  15100   Tue Dec 17 18:05:06 2019 YehonathanUpdatePSLMapping the PSL electronics

Updated the channel list (Attached):

1. Removed the MC steering mirror PZT channels

2. Added Sourcing/Sinking column

3. Recounted the mbbos correctly

4. Allocated Acromags:

Model Purpose No. Spare channels
XT1221 ai 7 11
XT1541 ao + src bo 2 9 ao
XT1121 src bo 2 4
XT1121 sink bo 1 4

I think we can start wiring.

  15103   Fri Dec 20 18:33:21 2019 YehonathanUpdatePSLMapping the PSL electronics

Final (hopefully) PSL channel list is attached with allocated Acromag channels. Wiring spreadsheet coming soon.

Current Acromag count:

AI 8
AO 2
Number of channels 8*8+2*8+4*16=144
Number of wires 144*2=288


  15104   Mon Dec 23 19:30:20 2019 YehonathanUpdatePSLMapping the PSL electronics

PSL wiring spreadsheet is ready. (But the link was stripped. Koji)

Link to a wiki page  with the link to the wiring spreadsheet (Yehonathan)

  15108   Wed Jan 1 04:53:11 2020 gautamUpdatePSLMapping the PSL electronics

For the IMC servo board, it'd be easiest to copy the wiring scheme for the BIO bits as is configured for the CM board (i.e. copy the grouping of the BIO bits on the individual Acromag units). This will enable us to use the latch code with minimal modifications (it was a pain to debug this the first time around). I don't see any major constraint in the wiring assignment that'd make this difficult.


PSL wiring spreadsheet is ready. (But the link was stripped. Koji)

Link to a wiki page  with the link to the wiring spreadsheet (Yehonathan)

  15110   Wed Jan 1 16:04:37 2020 YehonathanUpdatePSLMapping the PSL electronics



For the IMC servo board, it'd be easiest to copy the wiring scheme for the BIO bits as is configured for the CM board (i.e. copy the grouping of the BIO bits on the individual Acromag units). This will enable us to use the latch code with minimal modifications (it was a pain to debug this the first time around). I don't see any major constraint in the wiring assignment that'd make this difficult.


PSL wiring spreadsheet is ready. (But the link was stripped. Koji)

Link to a wiki page  with the link to the wiring spreadsheet (Yehonathan)


  3126   Mon Jun 28 11:27:08 2010 MeganUpdateElectronicsMarconi Phase Noise

Using the three Marconis in 40m at 11.1 MHz, the Three Cornered Hat technique was used to find the individual noise of each Marconi with different offset ranges and the direct/indirect frequency source of the rubidium clock.

Rana explained the TCH technique earlier - by measuring the phase noise of each pair of Marconis, the individual phase noise can be calculated by:

S1 = sqrt( (S12^2 + S13^2 - S23^2) / 2)

S2 = sqrt( (S12^2 + S23^2 - S13^2) / 2)

S3 = sqrt( (S13^2 + S23^2 - S12^2) / 2)

I measured the phase noise for offset ranges of 1Hz, 10Hz, 1kHz, and 100kHz (the maximum allowed for a frequency of 11.1Mhz) and calculated the individual phase noise for each source (using 7 averages, which gives all the spikes in the individual noise curves). The noise from each source is very similar, although not quite identical, while the noise is greater at higher frequencies for higher offset ranges, so the lowest possible offset range should be used. It appears the noise below a range of 10Hz is fairly constant, with a smoother curve at 10Hz.

The phase noise for direct vs indirect frequency source was measured with an offset range of 10Hz. While very similar at high and low frequencies for all 3 Marconis, the indirect source was consistently noisier in the middle frequencies, indicating that any Marconis connected to the rubidium clock should use the rubidium clock as a direct frequency reference.

Since I can't adjust settings of the Marconis at the moment, I have yet to finish measurements of the phase noise at 160 MHz and 80 MHz (those used in the PSL lab), but using the data I have for only the first 2 Marconis (so I can't finish the TCH technique), the phase noise appears to be lowest using the 100kHz offset except at the higher frequencies. The 160 MHz signal so far is noisier than the 11.1 MHz signal with offset ranges of 1 kHz and 10 Hz, but less noisy with a 100 kHz offset.

I still haven't measured anything at 80 MHz and have to finish taking more data to be able to use the TCH technique at 160 MHz, then the individual phase noise data will be used to measure the noise of the function generators used in the PSL lab.

  2869   Mon May 3 01:16:50 2010 ranaHowToElectronicsMarconi phase noise measurement setup

 To try the 3-corner hat method on the Marconis, I started to set up the measurement into the DAQ system.

I have set the bottom 2 in the PSL rack to 11.1 MHz. I use a ZP-3MH level 13 mixer as the phase detector. The top one is the LO, it has an output of +13 dBm.

The bottom one is the test unit, it has an output of +6 dBm (should be close to the right level - the IP3 point is +9 dBm). The top one has external DC FM modulation enabled with a FM dev range of 10 Hz.

Mixer output goes through a 50 Ohm in-line termination and then a BLP-5 low pass filter (Steve, please order ~7 of the BLP-1.5 or BLP-1.9 low pass filter from Mini-Circuits) and then into

the DC coupled of a SR560. After some gain and filtering that feedback goes back to the FM input of the top-Marconi to close the PLL. I adjusted the gain to be as small as possible and still stay locked and not

saturate the ADC.

The input to the SR560 is Tee'd into another SR560 with AC coupled input, G = 1000, low-noise. Its output is going directly to the ADC channel - C1:IOO-MC_DRUM1.

I calibrated the channel by opening the loop and setting the AC coupled gain to 1. This lets the Marconis beat at several Hz. The peak-peak signal is equivalent to pi radians.


As usual, I was befuddled by the FM input. For some reason I always forget that since its a straight FM input, we don't need any filtering to get a plain 1/f loop. The attached plot shows how we get bad gain peaking if you forget this and use a 0.03 Hz pole in the SR560.

The grey trace is the ADC signal with everything hooked up, but the RF input set to zero (via setting Carrier = OFF in the bottom Marconi). It is the measurement noise.

The BLUE trace is very close to the true phase noise beat of the two Marconis with a calibration error of ~5%. I have not corrected for the loop gain: its right now around a 1 Hz UGF and 1/f. Next, I will measure the loop and compensate for it in the DTT calibration.

Then I'll measure the relative phase noise of 3 of the signal generators to get the individual noises.

Bottom line is that the sensitivity of this approach is good and we should do this rather that use spectrum analyzers since its easy to get very long averages and high res spectra. To get 5x better sensitivity, we can just use the Rai-FET box instead of a SR560 for the readout, but just have to contend with its batteries. Also should try using BALUNs on the RF and LO signals to get rid of the ground loops.

  2879   Tue May 4 18:40:27 2010 ranaHowToElectronicsMarconi phase noise measurement setup

To check the UGF, I increased the gain of the PLL by 10 and looked at how much the error point got suppressed. The green trace apparently has a UGF of ~50 Hz and so the BLUE nominal one has ~5 Hz.

The second attachment shows the noise now corrected for the loop gain. IF the two signal generators are equally noisy, then you can divide the purple spectrum by sqrt(2) to get the noise of a single source.

The .xml file is saved as /users/rana/dtt/MarconiPhaseNoise_100504.xml

  2913   Tue May 11 18:58:49 2010 ranaHowToElectronicsMarconi phase noise measurement setup

Just a little while ago, at 2330 UTC on 5/11, I swapped the phase noise setup to use another Marconi - this time its the 3rd one from the top beating with the 4th one from the top (2nd from the bottom).

After a little while, I swapped over to beat the 33 w/ the 199. I now have all the measurements. For the measurement of the last pair, I inserted BALUN 1:1 transformers on the outputs of both signal generators'.

This last pair appears to be the quietest of the 3 and also has less lines. The lines are mainly at high frequency and are harmonics of 120 Hz. Probably from the Sorensen switching supplies in the adjacent rack.

I double checked that the 10 MHz sync cable was NOT plugged in to any of these during this and that the front panel menu was set to use the internal frequency standard. In the closed loop case, the beat frequency between the 33/199 pair changes by less than ~0.01 Hz over minutes (as measured by calibrating the control signal).


  2914   Wed May 12 02:21:56 2010 ranaHowToElectronicsMarconi phase noise measurement setup

Finally got the 3-cornered-hat measurement of the IFRs done. The result is attached.

s12, s23, & s31, are the beat signals between the 3 signal generators.

s1, s2, & s3 are the phase noise of the individual generators made by the following matlab calculation:

%% Do the hat
s1 = sqrt((s12.^2  + s31.^2 - s23.^2) / 2);
s2 = sqrt((s12.^2  + s23.^2 - s31.^2) / 2);
s3 = sqrt((s31.^2  + s23.^2 - s12.^2) / 2);

As you can see, there is now an estimate of the individual noises. We can do better by doing some fitting of the residuals.

The real test will be to replace the noise one here with the good Wenzel oscillator and see how well we can estimate its noise. If the 11 MHz crystals don't show up, I can just try this with the 21.5 MHz one for the PSL.

  2570   Thu Feb 4 12:29:04 2010 josephbUpdateComputersMartian IP switch over notes

What is the change:

We will be moving the 131.215.113.XXX ip addresses of the martian network over to a 192.168.XXX.YYY scheme.

What will users notice:

Computer names (i.e. linux1, scipe25/c1dcuepics) will not change.  The domain name martian, will not change (i.e. linux1.martian.).  What will change is the underlying IP address associated with the host names.  Linux1 will no longer be but something like  If everything is done properly, that should be it.  There should be no impact or need to change anything in EPICS for example.  However, if there are custom scripts with hard coded IP addresses rather than hostnames, those would need to be updated, if they exist.

What needs to be done:

Each computer and router will need to either be accessed remotely, or directly, and the configuration files controlling the IP address (and/or dns lookup locations) be modified.  Then it needs to be rebooted so the configuration changes take effect. I'll be making an updated list of computers this week (tracked down via their physical ethernet cables), and next week, probably on Thursday, and then we simply go down the list one by one.


For a linux machine, this means checking the /etc/hosts file and making sure it doesn't have old information.  It should look like:               localhost.localdomain localhost
::1             localhost6.localdomain6 localhost6

Then change the /etc/sysconfig/network-scripts/ifcfg-eth0 file (or ethX file depending on the ethernet card in question).  The IPADDR, NETWORK, and GATEWAY lines will need to be changed.  You can change the hostname (although I don't plan on it) by modifying the /etc/sysconfig/network file.

The /etc/resolv.conf file will need to be updated with the new DNS server location (i.e. to for example).


Simlarly to linux, the /etc/hosts file will need to be updated and/or simplified.  The /etc/defaultrouter file will need to be updated to the new router ip.  /etc/defaultdomain will need to be updated.  The /etc/resolv.conf will need to be updated with the new dns server.


Looking at the vxWorks machines, the command bootChange can be used to view or edit the IP configuration.

The following is an example from c1iscey.

-> bootChange

'.' = clear field;  '-' = go to previous field;  ^D = quit

boot device          : eeE0
processor number     : 0
host name            : linux1
file name            : /cvs/cds/vw/pIII_7751/vxWorks
inet on ethernet (e) :
inet on backplane (b):
host inet (h)        :
gateway inet (g)     :
user (u)             : controls
ftp password (pw) (blank = use rsh):
flags (f)            : 0x0
target name (tn)     : c1iscey
startup script (s)   :
other (o)            :

value = 0 = 0x0

By updating the the host (name of machine where its mounting /cvs/cds from - i.e. linux1), inet on ethernet (the IP of c1iscey) and host inet (linux1's ip address), we should be able to change all the vxWorks machines.


The DNS server running on linux1 will need to be updated with the new IPs and domain information.  The host file on linux1 will also need to be updated for all the new IP addresses as well.

This will need to be handled carefully as the last time I tried getting away without the host file on linux1, it broke NFS mounting from other machines.  However, as long as the host on linux1 is kept in sync with the dns server files everything should work.

  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.

  4135   Tue Jan 11 14:05:11 2011 josephbUpdateComputersMartian host table updated daily

I created two simple cron jobs, one running on linux1 and one running on nodus, to produce an updated copy of the martian host table linkable from the wiki every day.

The scripts live in /opt/rtcds/caltech/c1/scripts/AutoUpdate/.  One is called  updateHostTable.cron and run on linux1 everyday at 4 am, and the other is called moveHostTable.cron which is run on nodus everyday at 5am.

The new link has been added to the Martian Host table wiki page  here.


  14465   Tue Feb 19 19:03:18 2019 ranaUpdateComputersMartian router -> WPA2

I have swapped our martian router's WiFi security over to WPA2 (AES) from the previous, less-secure, system. Creds are in the secrets-40-red.

  10196   Mon Jul 14 16:51:07 2014 NichinUpdateElectronicsMartian table updated, Named server restarted

 [Nichin, Jenne]

The martian lookup tables are located at /etc/bind/zones/martian.db  and etc/bind/zones/rev.113.168.192.in-addr.arpa

Jenne updated these to include santuzza.martian



The method to restart named server given at  https://wiki-40m.ligo.caltech.edu/Martian_Host_Table  also does not work.

I restarted it using  >sudo /etc/init.d/bind9 restart

The named server is now updated and works fine. :)  I will update the 40m wiki now.

  1339   Thu Feb 26 01:24:44 2009 YoichiUpdateComputersMartian wireless is back
Today, a new wireless router arrived.
I configured and installed it. Now the martian wireless network is back.
I updated the wiki page about the wireless network.
  1325   Thu Feb 19 16:29:43 2009 YoichiUpdateComputersMartian wireless router bad
The Martian wireless router is dead.
I rebooted it several times, but it hangs up in a minute.
I will ask steve to buy a new one.
  9026   Mon Aug 19 09:54:13 2013 SteveUpdatesafetyMasayuki receives safety training

Masayuki Nakano, a student of Seiji's from ICRR / U Tokyo, is visiting us here at the 40m lab for the next couple months.

He received 40m specific basic safety training this morning.

  16135   Wed May 12 14:23:20 2021 JordanUpdateSUSMass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units
  16136   Wed May 12 16:53:59 2021 KojiUpdateSUSMass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units

No, this is the property of the suspension assembly. The mass says 10kg

Could you do the same for the testmass assembly (only the suspended part)? The units are good, but I expect that the values will be small. I want to keep at least three significant digits.

  16137   Wed May 12 17:06:52 2021 JordanUpdateSUSMass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units

Here are the mass properties for the only the test mass assembly (optic, 3" ring, and wire block). (Updated with g*mm^2)


No, this is the property of the suspension assembly. The mass says 10kg

Could you do the same for the testmass assembly (only the suspended part)? The units are good, but I expect that the values will be small. I want to keep at least three significant digits.


  16146   Wed May 19 18:29:41 2021 KojiUpdateSUSMass Properties of SOS Assembly with 3"->2" Optic sleeve, in SI units

Calculation for the SOS POS/PIT/YAW resonant frequencies

- Nominal height gap between the CoM and the wire clamping point is 0.9mm (cf T970135)

- To have the similar res freq for the optic with the 3" metal sleeve is 1.0~1.1mm.
As the previous elog does not specify this number for the current configuration, we need to asses this value and the make the adjustment of the CoM height.

  3740   Tue Oct 19 00:24:07 2010 DmassOmnistructureElectronicsMassive restocking of the 40m

I had a number of delinquent items on the sign out list from the 40m. I returned about half, and ordered replacements for most of the other half.

I put the photodiodes on the SP table, and the 560 on the electronics  bench.

  120   Tue Nov 20 18:35:20 2007 JohnHowToComputersMatLab in Emacs
If you can't get MatLab to run in emacs try adding the following to the .emacs file

(setq matlab-shell-command-switches '("-nojvm"))

This stops the gui opening.

To start MatLab type M-x matlab-shell.
To enter MatLab mode M-x matlab-mode.

I've done this on LINUX3.

To run MatLab in emacs under windows one can use MatLabShell http://www.cs.umb.edu/~ram/matlabShell/index.html
  251   Mon Jan 21 23:30:03 2008 AndreyUpdateComputer Scripts / ProgramsMatlab Program for Q-factor measurements (XARM -> ITMX and ETMX)

Finally I overcame difficulties with adapting Sonia's Matlab programs for XARM (Sonia's program was for MC),

and now there exists a Matlab program that makes a fit of a ringdown curve and calculates Q-factor for a mirror ITMX.

Specifically, this program allows to measure ringdown, fit it and calculate Q-factor for the ITMX-mirror for a specific value of

Attached is a plot of a ringdown curve and its fit for the value 4.0 in channel "C1:SUS-ITMX_SUSPOS_GAIN".

Calculations yield the result Q=3.7+-0.2 for the value 4.0 in channel "C1:SUS-ITMX_SUSPOS_GAIN".

As Robert started 10 minutes ago the long procedure of the whole interferometer locking,
I cannot disturb the interferometer now, so I will measure Q-factors for various combinations of suspension damping gain on Tuesday.

I will also easily modify the program for measuring Q-factors of ETMX-mirror and make measurements with ETMX on Tuesday.

The Matlab scripts are in directory /cvs/cds/caltech/users/rodionov/Q-Factors/
  12859   Wed Mar 1 16:00:41 2017 gautamUpdateComputer Scripts / ProgramsMatlab R2016b installed

Since it would be nice to have the latest version of Matlab, with all its swanky new features (?), available on the control room computers and Optimus, I downloaded Matlab R2016b and activated it with the Caltech Campus license. I installed it into /cvs/cds/caltech/apps/linux64/matlab16b. Specifically, I would like to run the coating optimization code on Optimus, where I can try giving it more stringent convergence criterion to see if it converges to a better spot.

I trust that this way, we don't interfere with any of the rtcds stuff.

If I've done something illegal license-wise or if this is likely to cause havoc, please point me to what is the correct way to do this.

GV 18 Mar 2017: Though I installed this using the campus network license key, this seems to only work on Rossa. If I run it on the other control room machines/Optimus, it throws up a licensing error. I will check with Larry W. as to how to resolve this...


  6083   Wed Dec 7 20:55:44 2011 Vladimir, DenUpdatedigital noiseMatlab error


It would be useful to see some plots so we could figure out exactly what magnitude and phase error correspond to "gross" and "miserable".

To show why Matlab is bad in filtering at small cut-off frequencies we did the same thing in Matab, Octave and R: we've taken the low-pass chebyshev filter of the type 1, order 6, ripple 1 dB, the sampling frequency was 16384 Hz and cut-off frequency varied from 1 to 1000 Hz. Here is the plot for the gain of the zpk model versus to cut-off frequency.


We can see that Matlab's gain shows surprising gains for low cut-off frequencies through for > 100 Hz it is fine. In the next table we compare gain from Foton, Matlab, R and Octave for the same filter. So Foton is also good

freq R_gain matlab_gain octave_gain Foton_gain
1 3.05186270655452e-24 4.8824152e-22 3.05186271e-24 3.05186e-24
10 3.04698335947093e-18 1.8268825e-16 3.04698336e-18 3.04698e-18
100 2.99910841393644e-12 2.9991084e-12 2.99910841e-12 2.99911e-12
1000 2.60247212721439e-06 2.6024721e-06 2.60247213e-06 2.60247e-06
  281   Mon Jan 28 17:16:54 2008 AndreyConfigurationComputersMatlab libraries DO NOT WORK properly sometimes

Working in Matlab, I encountered at two different times today the license distribution problem:

??? License checkout failed.
License Manager Error -4
Maximum number of users for Curve_Fitting_Toolbox reached.
Try again later.
To see a list of current users use the lmstat utility or contact your License Administrator.

Troubleshoot this issue by visiting:
  10751   Wed Dec 3 21:41:12 2014 JenneUpdateComputer Scripts / ProgramsMatlab license updated

It seems that the old Matlab servers went down a week or so early, so I have updated the Matlab license information in 


per the instructions on https://www.imss.caltech.edu/content/updating-matlab-license-file

EDIT: Q did this also for the control room iMac

  777   Thu Jul 31 16:11:22 2008 josephbConfigurationComputersMatlab on Megatron
Matlab now works on megatron.

I did a few things:

1) Added to the PATH environment variable. Did this in .bash_profile in the /home/controls directory by adding the line

export PATH

This probably should be somewhere else up further up the line, but I was too lazy to figure it out.

2)Fixed a gateway mistake I had added earlier so the megatron could use the NAT router and see the outside world so yum worked.

3) Removed the i386 based libXp and openmotif packages.

4) Installed the x86_64 based libXp and openmotif packages.

Edit: Forgot that I also added the following line to the /etc/fstab file in order to mount the shared code. This was stolen directly from Rosalba's /etc/fstab file. This was so that it could see the matlab code.
linux1:/home/cds/ /cvs/cds nfs rw,bg,soft 0 0
  8774   Thu Jun 27 21:59:42 2013 ranaUpdateComputer Scripts / ProgramsMatlab upgraded

I moved the old matlab directory from /cvs/cds/caltech/apps/linux64/matlab_o to /cvs/cds/caltech/apps/linux64/matlab_oo

and moved the previously current matlab dir from /cvs/cds/caltech/apps/linux64/matlab to /cvs/cds/caltech/apps/linux64/matlab_o.

And have installed the new Matlab 2013a into /cvs/cds/caltech/apps/linux64/matlab.

Since I'm not sure how well the new Matlab/Simulink plays with the CDS RCG, I've left the old one and we can easily revert by renaming directories.

  15988   Thu Apr 1 21:13:54 2021 AnchalUpdateSUSMatrix results, new measurement set to trigger
New Input matrix used for MC2 (C1:SUS-MC2_INMATRIX_ii_jj
POS 0.2464 0.2591 0.2676 0.2548 -0.1312
PIT 1.7342 0.7594 -2.494 -1.5192 -0.0905
YAW 1.2672 -2.0309 -0.9625 2.3356 -0.2926
SIDE 0.1243 -0.1512 -0.1691 0.1064 0.9962

New output matrix for MC2 (C1:SUS-MC2_TO_COIL_ii_jj_GAIN)
UL 1 1.022 0.6554
UR 1 0.9776 -1.2532
LL 1 -0.9775 1.2532
LR 1 -1.0219 -0.6554

Measured Sensing Matrix (Cross Coupling) (Sensed DOF x Excited DOF)
  Excited POS Excited PIT Excited YAW
Sensed POS 1 1.9750e-5 -3.5615e-6
Sensed PIT 0 1 -6.93550e-2
Sensed YAW 0 -2.4429e-4 1

A longer measurement is set to trigger at 5:00 tomorrow on April 2nd, 2021. This measurement will run for 35 iterations with an excitation duration of 120s and bandwidth for CSD measurement set to 0.1 Hz. The script is set to trigger in a tmux session named 'cB' on pianosa.

  15993   Fri Apr 2 15:22:54 2021 gautamUpdateSUSMatrix results, new measurement set to trigger

How should I try to understand why PIT and YAW are so different? 

New output matrix for MC2 (C1:SUS-MC2_TO_COIL_ii_jj_GAIN)
UL 1 1.022 0.6554
UR 1 0.9776 -1.2532
LL 1 -0.9775 1.2532
LR 1 -1.0219 -0.6554
  439   Tue Apr 22 22:51:30 2008 ranaConfigurationIOOMcWFS Status
I've been working a little on the MC WFS in the last few days. I have made many
changes to the sensing matrix script and also to the MCWFSanalyze.m script.

The output matrix, as it was, was not bad at low frequencies but was making noise in
the ~1 Hz band. Turning the gain way down made it do good things at DC and not make
things work higher.

The output matrix generating script now works after Rob fixed the XYCOM issue. Not sure
what was up there. As Caryn mentioned the SUS2.ini channels were all zero after Andrey's
PEM power cycle a few days ago. Rob booted c1susvme to get the SUS1 channels back and
today we did c1susvme2 to get the IOO-MC_L et. al. back.

Even after doing the matrix inversion there is some bad stuff in the output matrix. I
checked that the sensing matrix measurement has good coherence and I measured and set the
MC WFS RF phases (they were off by ~20-30 deg.). Still no luck.

My best guess now is that the RG filters I've used for POS damping and the movement of the
beam on the MC mirror faces has made a POS<->YAW instability at low frequencies. My next
move is to revert to velocity damping and see if things get better. Should also try redoing
the A2L on the MC1-3.
  1503   Mon Apr 20 20:00:44 2009 ranaConfigurationIOOMcWFS gains re-allocated
Since it looks like the night time people have been running with a WFS gain of 0.05 and I like the slider
to be at 1.0, I lowered all of the WFS1/2_P/Y gains by 10 and increased the overall slider from 0.05 to 1.0.
So the loop gains are now 2x higher; with it like this I guess the UGFs are in the ~0.2-0.5 Hz range.
  545   Thu Jun 19 15:52:06 2008 AlbertoConfigurationComputersMeasure of the current absorbed by the new Megatron Computer
Together with Rich Abbot, sam Abbot and I measured the current absorbed by the new Megatron computer that we installed yesterday in the 1Y3 rack. The computer alone absorbs 8.1A at the startup and then goes down to 5.9A at regime. The rest of the rack took 5.2A without the computer so the all rack needs 13.3 at the startup and the 11.1A.

We also measured the current for the 1Y6 rack where an other similar Sun machine has been installed as temporary frame builder and we get 6.5A.

Alberto, Rich and Sam Abbot
  13080   Mon Jun 26 09:39:15 2017 NaomiSummaryGeneralMeasure transfer functions of Mini-Circuits filters

I have spent my first few days as a SURF getting experience working with the Network/Spectrum Analyzer (AG 4395A). After an introduction to the 40m by Koji, I was tasked with using the AG4395A to measure the transfer function of several filters (for example, Mini-Circuits Low Pass Filter SLP-30). I am now familiar with configuring the AG 4395A, taking a single set of data using a command from one of the control computers, and plotting the dataset as a Bode plot (separate plots for magnitude and phase) using Python.

To Do:

  • Use AGmeasure to take multiple datasets with a single command.
  • Plot multiple datasets for each filter on a single Bode plot and perform some statistical analysis. 

To experiment with plotting multiple datasets on a single Bode plot, I used a single dataset from the Network Analyzer using the SLP-30 filter and added random noise to create ten datasets to plot. I am attaching the resulting Bode plot, which has the ten generated sets of data plotted along with their average.

We discussed with Rana and Koji how to interpret this type of dataset from the Network Analyzer. Instead of considering the magnitude and phase as separate quantities, we should consider them together as a single complex number in the form H(f) = M exp(iπP/180), where M is the magnitude and P is the phase in degrees. We can then find the average value of the measured quantity in its complex number form (x + iy), as opposed to just taking the average of the magnitude and phase separately.  

  1662   Tue Jun 9 11:29:07 2009 JenneUpdateoplevsMeasured ETMY oplev beam size...put everything back

I measured the ETMY oplev beam size at a couple different distances away from the HeNe by taking out the steering mirror and letting the light propagate a ways.  I put the steering mirror back, aligned the oplev, and was able to relock the Yarm, so I think it's all back as it has been the last couple of weeks.


Now I need t o do some geometry and ray-tracing matrices to decide what focal length lens to buy, then we'll have  a shiny new ETMY oplev. 

  2317   Mon Nov 23 21:30:29 2009 JenneUpdateLSCMeasured MC length

With Koji's help, I measured the length of the Mode Cleaner.

The new modulation frequencies (as quoted on the Marconi front panels) are: 

165.980580 MHz

 33.196116 MHz

132.784464 MHz

199.176696 MHz

The Frequency Counter readback is 165980584.101 Hz (a 4Hz difference).  All of the Marconi's front-panel frequencies read ###.##### MHz Ext, and the Frequency standard has it's "locked" light illuminated, and the 1pps input light blinking, so I think everything is still nicely locked to the frequency standard, and the frequency standard is locked to the GPS.

While changing the marconi's, I accidentally touched the MC's 29.5 MHz marconi.  It is set back to the nominal value (according to Kiwamu's rack photos) of 29.485MHz.  But the phase might be sketchy, although hopefully this doesn't matter since we don't do a double demodulation with it.

I also ran the scripts in the wiki page: How To/Diagonalize DRMI Length Control to set the DD Phases.



  2319   Tue Nov 24 08:00:16 2009 ranaUpdateLSCMeasured MC length

I propose that from now on, we indicate in the elog what frequencies we're referring to. In this case, I guess its the front panel readback and not the frequency counter -- what is the frequency counter readback? And is everything still locked to the 10 MHz from the GPS locked Rubidium clock?

Plus, what FSS Box? The TTFSS servo box? Or the VCO driver? As far as I know, the RC trans PD doesn't go through the FSS boxes, and so its a real change. I guess that a bad contact in the FSS could have made a huge locking offset.


ELOG V3.1.3-