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ID Date Author Typeup Category Subject
  4746   Thu May 19 00:23:44 2011 ranaUpdateCDSdiagonalization of MC input matrix

 I've moved all of my SOS peak fitting stuff into the scripts area so that Leo can make it better:


findPeaks.m gets the data and makes the fitted spectra that I put in the previous entry.

findMatrix.m is the barely started script that ought to take the TF data and output the matrix to the MEDM screen.

  4747   Thu May 19 03:13:54 2011 kiwamuUpdateElectronicsREFL11 not working

I took REFL11 out from the AS table for a health check because it wasn't working properly.

The symptoms were :

   - a big offset of ~ -3 V on the RF output. No RF signals.

   - The DC output seemed to be okay. It's been sensitive to light.

I did a quick check and confirmed that +/- 5V were correctly supplied to the op-amps.

It looks that the last stage (MAX4107) is saturated for some reasons. Need more inspections.

At the moment the REFL11 RFPD is on the bench of the Jenne laser.


  4748   Thu May 19 12:09:41 2011 josephbUpdateCDSAA filter box pulled from 1X5, optic suspensions currently off

[Steve, Joe]

Steve pulled the top AA filter box from 1X5 which handled some of the suspensions channels.  We turned off all the watchdogs before pulling it out, as well as recorded which cables were connected to which inputs.

The case  is undergoing a structural modification to have the ADC adapter card which previously was loosely connected via cables, securely attached to the case.

Steve still wants to do some cabling in the rack while the box is out, and will return it this afternoon once he has finished that.

  4749   Thu May 19 16:46:20 2011 kiwamuUpdateLSCc1lsc model : input channels rearanged

According to Suresh's LSC rack design I rearranged the input channels of the c1lsc model such that the analog signals and the ADC channels are nicely matched.

Also I updated the c1lsc model in the svn with a help from Joe. The picture below is a screen shot of the input channels in the model file after I edited it.


  4750   Thu May 19 17:53:03 2011 steveUpdateCDSAA filter box modified at 1X5


[Steve, Joe]

Steve pulled the top AA filter box from 1X5 which handled some of the suspensions channels.  We turned off all the watchdogs before pulling it out, as well as recorded which cables were connected to which inputs.

The case  is undergoing a structural modification to have the ADC adapter card which previously was loosely connected via cables, securely attached to the case.

Steve still wants to do some cabling in the rack while the box is out, and will return it this afternoon once he has finished that.

 Job is done. Sus damping are back on. Cabling-strain reliefing are  not finished yet at 1X5 and 1X4

Attachment 1: P1070727.JPG
  4751   Thu May 19 19:41:17 2011 SureshUpdateRF SystemDAQ channel Assignments for RF PDs

[Kiwamu, Suresh]

In trying to keep the wiring of the LSC rack as neat as possible, we came up with the following channel assignments of the RF PD signals. 

PDI = PD Interface, The PD Interface D-type connectors (#1 to #12) are numbered:  Top -> Bottom and Left -> Right in ascending order. 

The Analog channels on the LSC Whitening Filter boards are numbered similarly, 1 to 32 in four sets.


  4752   Fri May 20 01:02:50 2011 loose connection hunterUpdateSUSloose connection on ETMY rack

The UL signal of the shadow sensor on ETMY went to zero this evening.

This was due to a loose connection on the cross connection board on the 1Y4 rack.

In order to make them tighten, a combination of stand-offs and screws were installed on the connectors. They won't be loose any more.


  4753   Fri May 20 03:01:17 2011 kiwamuUpdateLSClocking status

(PRMI locking)

Since REFL11 has gone I tried locking the PRMI with combination of REFL55 and AS55.

Without any pain the lock of PRMI was achieved successfully. AS55 was used to sense MICH and REFL55 was used for PRC.



Additionally I was modifying several scripts which are invoked from C1IFO_CONFIGURE.adl. Some details about the scripts will be uploaded on the wiki later.

An important thing is that now we are able to use the "restore" commands for the Y arm, X arm, Michelson and PRM locking.

The scripts will automatically acquire the lock of each DOF.  The image below is just a screen shot of the medm screen where you can call the scripts.



( Still to do)

   * PRM actuator response measurement

   * PRC noise budget

   * MICH-PRC actuator decoupling

  4754   Fri May 20 03:29:04 2011 kiwamuUpdateCDSBinary IO box on 1X5 : LEDs off

[Steve / Kiwamu]

 When Steve was working on the strain reliefs on 1X5 he found that some LEDs on the back side of the binary IO boxes were off.

There are 4 binary IO boxes and their power are directly supplied from Sorensens. According to the display of the Sorensens, the power are correctly generated.

Steve and I checked a picture of the boxes taken before he started working and we found it's been like this.

It might be just a problem of the LEDs or the fuses are blown, but anyway it needs an inspection.

Here is a picture of the back side of the boxes. You can see some LEDs are on and some are off.


  4755   Fri May 20 05:41:22 2011 SureshUpdateRF SystemDemod board measurements

The POP110 board which had the large Amplitude and Phase unbalances was examined today.  It turned out that there was some stray solder which had connected the Sum port of the PSCQ-2-120 splitter to its body (ground).  After I removed that the amplitude unbalance was 0.3dB however the phase was 105deg.  The phase reduced to 90 deg only if the power on the splitter is around 19 dBm.  So removed the AT1 (10dB attenuator) and the phase unbalance dropped to 91 deg.  However this is not a sustainable solution as the ERA-5 max output is about 19.5 dBm.

As this is a side band power monitor (and not a length sensing RFPD), we can make do with a poorer phase.  I will therefore replace the AT1 and adjust the residual phase with cable delay lines.  


I measured the amplitude and phase imbalances of the demod boards which have been modified.  This is just a basic health check.  We hope to use the script that Kiwamu is developing for a more accurate test.  The script can also use these measurements as a sanity check.  POP110  requires some further attention. 



The RF distribution box outputs corresponding to the demod board (eg. AS55_LO --> AS55_demod) were used as LO sources.  The RF signal was generated with a Marconi and held a kHz away from the LO frequency.  The amplitude and phase unbalance were measured with SR785.  The RF Power meter was used to check the LO power in each case.




  4756   Fri May 20 11:37:44 2011 KojiUpdateElectronicsREFL11 fixed (REFL11 not working)

- Found the inductor which shunts the positive input of MAX4107 was not touching the ground.
This left the positive input level undetermined at DC. This was why MAX had been saturated.
The PCB has a cut, so it was surprising once the circuit worked.

- Resoldered the inductor to the ground. This made the circuit responding to the intensity-modulated beam.

- But the resonances and the notches were totally off, and the 200MHz oscillation has resurrected.

- Attached 40Ohm+22pF network between the neg-input of MAX and the gnd. This solved the oscillation.

- Made the tuning and the characterizations. The PD is on Kiwamu's desk and ready to go.

More to come later

I took REFL11 out from the AS table for a health check because it wasn't working properly.

The symptoms were :

   - a big offset of ~ -3 V on the RF output. No RF signals.

   - The DC output seemed to be okay. It's been sensitive to light.

I did a quick check and confirmed that +/- 5V were correctly supplied to the op-amps.

It looks that the last stage (MAX4107) is saturated for some reasons. Need more inspections.

At the moment the REFL11 RFPD is on the bench of the Jenne laser.


Attachment 1: REFL11_transimpedance.pdf
  4757   Sat May 21 06:19:46 2011 kiwamuUpdateLSCDRMI trial : no luck

I will try with POY55 that Koji prepared today.

  4758   Sat May 21 17:02:38 2011 KojiUpdateElectronicsAlberto's 11MHz was modified to POP55MHz

- Resonant at 55MHz. The transimpedance is 258Ohm. That is about half of REFL55 (don't know why).

- 11MHz&110MHz notch

- The 200MHz oscillation of MAX4106 was damped by the same recipe as REFL11.



Attachment 1: POP55_schematic_110520_KA.pdf
POP55_schematic_110520_KA.pdf POP55_schematic_110520_KA.pdf
Attachment 2: POP55_transimpedance.pdf
  4759   Mon May 23 00:36:51 2011 kiwamuUpdateLSCDRMI trial : sucess

Eventually the DRMI was locked.

I was struggling to find a good signal port for SRC over the weekend and finally found AS55_I worked somehow. I used :

   REFL11_I --> PRC

   AS55_Q   --> MICH

   AS55_I    --> SRC

A configuration script was prepared such that someone can try this configuration by clicking a button on the C1IFO_CONFIGURE.adl screen.

I don't think this signal extraction scheme is the best, but now we can find better signal ports by shaking each DOF and looking at each signal port.

More details will be reported in the morning.


I will try with POY55 that Koji prepared today.


  4760   Mon May 23 12:27:26 2011 kiwamuUpdateLSCDRMI trial : details

(PRMI locking with slightly misaligned SRM)

 First I tried locking PRC and MICH with a little bit misaligned SRM. This condition allowed me to search for a good signal port for SRC.

In this locking, REFL11_I was used to lock PRC and AS55_Q was used for MICH. This is the same scheme as the current PRMI locking.

Since the alignment of SRM was close to the good alignment, I expected to see fringes from SRC in some signal ports (i.e. REFL55, POY55 and so on).

Sometimes a fringe of SRC disturbed AS55_Q and broke the MICH locking, so I had to carefully misalign SRM so that the SRC fringes are small enough to maintain the lock of MICH.


(Looking for a good signal port for SRC)

 After I locked the PRMI with slightly misaligned SRM, I started looking for a good signal port for SRC.

At the beginning I tried finding a good SRC port by shaking SRM at 100 Hz and looked at the power spectra of all the available LSC signals.

I was expecting to see a 100 Hz peak in the spectra, but this technique didn't work well because SRC wasn't within the linear range and hence didn't produce linear signals.

So I didn't see any strong signals at 100 Hz and finally gave up this technique.

Then I started looking for a PDH-like signal in time series and immediately found AS55_I showed large PDH-like signals.

So I started using the AS55_I for the SRC locking and eventually succeeded.


(Two tips for the DRMI locking)

During the locking of DRMI, I found two tips that made the locking quite smooth.

 - Triggered locking

   Since every LSC signal ports showed large signals from PRC somehow, feeding back the signals made the suspensions crazy.

   So I used triggered locking for the PRC and MICH locking to avoid unwanted kicks on BS and PRM.

   If  the DC of REFL goes above a certain level, the control of  PRC starts. Also if the DC of AS goes below a certain level the control of MICH starts.

  These triggers make the lock smoother.

 - Do not use resonant gain filters

  This is really a stupid tip. When I was trying to lock MICH, the lock became quite difficult for some reasons.

  It looked there was an oscillation at 3 Hz every time the MICH control started. It turned out that a 3 Hz resonant gain filter had been making it difficult.

  All the resonant gain filters should be off when a lock acquisition is taken place.

Quote from #4759

Eventually the DRMI was locked.

More details will be reported in the morning.


  4762   Mon May 23 18:10:41 2011 kiwamuUpdateLSCf2p filters on PRM : not good

During the DRMI trial I noticed that the f2p filters on PRM is not quite effective (i.e. pushing PRM in POS direction makes misalignments).

I checked the f2p filters in an easy way. I pushed POS at 0.01 Hz with an amplitude of 1000 counts and looked at the oplev error signals with / without the f2p filters.

The picture below is a time series of the POS excitation, the oplev's PITCH and YAW error signals.

You can see there still is a big coupling from POS to YAW after the f2p filters were enabled. (Its supposed to be like this)

I will redo the f2p measurement on PRM.


  4768   Fri May 27 17:52:53 2011 steveUpdateLSCLSC rack cables strain relieved & labeled

LSC rack 1Y2 cables are strain relieved and labeled. Spare and/or obsolete cables are laid out on the top of the beam tube and on the outside of the rack.

The POY 110 MHZ demodboard has a very touchy position in the VME crate. Watch out for it! It has to be fixed.

  4769   Mon May 30 23:14:27 2011 valeraUpdateASCY arm initial alignment

I closed all 8 dither loops for the Y arm initial alignment: 2x2 centering servo (this worked before) and 2x2 input beam servo for both pitch and yaw.

So far it looks pretty good - the error points go to zero and the arm power goes up to 1.

The offloading to the alignment biases and the PZTs is not yet automated.

Today the PMC, MC, and Y arm were very cooperative and a pleasure to work with.

  4770   Tue May 31 11:26:29 2011 josephbUpdateCDSCDS Maintenance

1) Checked in the changes I had made to the c1mcp.mdl model just before leaving for Elba.

2) The c1x01 and c1scx kernel modules had stopped running due to an ADC timeout. 

According to dmesg on c1iscex, they died at 3426838 seconds after starting (which corresponds to ~39 days).  "uptime" indicates c1iscex was up for 46 days, 23 hours. So my guess is about 8 days ago (last Monday or Tuesday),  they both died when the ADCs failed to respond quick enough for an unknown reason.

I used the kill scripts (in /opt/rtcds/caltech/c1/scripts/) to kill c1spx, c1scx, and c1x01.  I then used the start scripts to start c1x01, then c1scx, and then finally c1spx.  They all came up fine.

Status screen is now all green.  I renabled damping on ETMX and it seems to be happy. A small kick of the optic shows the approriately damped response.

  4772   Tue May 31 14:29:00 2011 jzweizigUpdateCDSframes

There seems to be something strange going on with the 40m frame builder.
Specifically, there is a gap in the frames in /frames/full near the start of
each 100k second subdirectory. For example, frames for the following times are missing:


To summarize, after writing the first two frames in a data directory, the next ~10 minutes of frames are usually missing. To make matters worse (for
the nds2 frame finder, at least) the first frame after the gap (and all successive frames) start at an arbitrary time, usually not aligned to a 16-second boundary. Is there something about the change of directories that is causing the frame builder to crash? Or is the platform/cache disk too slow to complete the directory switch-over without loss of data?

  4773   Tue May 31 15:45:37 2011 JamieUpdateCDSc1iscey IOchassis powered off for some reason. repowered.

We found that both of the c1iscey models (c1x05 and c1scy) were unresponsive, and weren't coming back up even after reboot.  We then found that the c1iscey IOchassis was actually powered off.  Steve's accepts some sort of responsibility, since he was monkeying around down there for some reason.  After powerup and reboot, everything is running again.

  4775   Tue May 31 17:30:42 2011 steveUpdateSUSETMY damping restored

ETMY's watch dogs were found tripped. They were restored.

  4776   Wed Jun 1 11:31:50 2011 josephbUpdateCDSMC1 LR digital reading close to zero, readback ~0.7 volts

There appears to be a bad cable connection somewhere on the LR sensor path for the MC1 optic.

The channel C1:SUS-MC1_LRPDMon is reading back 0.664 volts, but the digital sensor channel, C1:SUS-MC1_LRSEN_INMON, is reading about -16.  This should be closer to +1000 or so.

We've temporarily turned off the LRSEN filter module output while this is being looked into.

I briefly went out and checked the cables around the whitening and AA boards for the suspension sensors, but even after wiggling and making sure everything was plugged in solidly.  There was one semi-loose connection, but it wasn't on the MC1 board, but I pushed it all the way in anyways.  The monitor point on the AA board looks correct for the LR channels, although ITMX LR struck me as being very low at about -0.05 Volts.

According to data viewer, the MC1 LR sensor channel went bad roughly two weeks ago, around 00:40 on 5/18 UTC, or 17:40 on 5/17 PDT.



It appears the AA board (or possibly the SCSI cable connected to it) is the problem in the chain.

  4777   Wed Jun 1 13:33:22 2011 koji, taraUpdateElectronicsTTFSS #7

We replaced GE81 by PZT2907A (PNP transistor) in TTFSS #7, it's working fine.

  Last time I broke Q4 transistor, which is used in the low noise power module for TTFSS, (see the schematic) and could not find another PZT2907A, so GE81 was used temporarily. Now we changed it back to PZT2907A as designed.  I tested it by checking the voltage outputs of the board. It works fine, all voltage outputs are correct. I labeled one of the slot on the blue cabinet tower and kept the rest of the transistors there.



I brought TTFSS set #7 to 40m and kept it in the electronic cabinet.

note that Q4 transistor has not been replaced back to PZT2907A yet. It's still GE82.

Q3 is now pzt3904, not PZT2222A.



  4778   Wed Jun 1 21:56:43 2011 KojiUpdateGeneralaLIGO BBPD / Green PD final result

Here is the conclusive result for the circuit configuration for aLIGO BBPD and 40m Green PD.

- Use Mini-circuits MAR-6SM for the RF preamplifier. The 50Ohm input impedance is used for the RF transimpedance.
  The maximum output is ~4dBm.

- Use Mini-circuits GALI-6 for the RF middle power amp. The gain is 12dB and the amplifier is linear up to +17dBm. i.e. This is still linear at the maximum output level of MAR-6SM.

- The total RF transimpedance is ~2k. The DC transimpedance is also 2k.

- The bandwidth is 80MHz with FFD100 and internal 25V bias. When S3399 is used, the bandwdith goes up to 180MHz
although the responsivity of FFD100 at 1064nm is better than S3399 by a factor of 1.5. At the 40m we will use S3399 for the green BB PD.

- By adding an LC network next to the PD, one of the unnecessary signal can be notched out.
As an example, 9MHz notch was placed for the FFD100 case.

- Noise level: ~10pA/rtHz as a floor noise level at around 30MHz. This corresponds to the equivalent dark current of 0.4mA.

Matt has finished the PCB layout. We will order small first batches, and stuff it for the test. Some of these will be the 40m green PD.

Attachment 1: PD_response.pdf
PD_response.pdf PD_response.pdf PD_response.pdf PD_response.pdf PD_response.pdf PD_response.pdf
Attachment 2: linearity_GALI_6.pdf
  4780   Thu Jun 2 16:23:42 2011 JamieUpdateSUSSUS control models updated to use new sus_single_control library part

A new library part was made for the single suspension controller (it was originally made from the c1scx controller), using the following procedure:

  1. Opened c1scx model (userapps/trunk/sus/c1/models/c1scx)
  2. Cut ETMX subsystem block out of SUS subsystem
  3. Pasted ETMX block into new empty library, and renamed it C1_SUS_SINGLE_CONTROL
  4. Tweaked names of inputs, and generally cleaned up internals (cosmetically)
  5. Saved library to: userapps/trunk/sus/c1/models/lib/sus_single_control.mdl

Once the new sus_single_control library part was made and the library was committed to the cds_user_apps repo, I replaced all sus controller subsystems with this new part, in:

  • c1scx
  • c1scy
  • c1sus (x5 for each vertex mass)

All models were rebuild, installed, and tested, and everything seems to be working fine.

  4781   Thu Jun 2 16:31:41 2011 JamieUpdateCDSaquired SUS channel name suffixes changed from _DAQ to _DQ

CDS changed the suffix for all aquired channel names from _DAQ to _DQ.  When we rebuilt the sus models, described in the previous log, the channel names were changed and consequently the channel files were completely rewritten.

To fix the issue, the latest archived channel file was copied back into the chans directory, and the suffixes were changed, as so:

cd /opt/rtcds/caltech/c1/chans
cp archive/C1SUS_110602_155403.ini  C1SUS.ini
sed -i 's/DAQ/DQ/g' C1SUS.ini

We then restarted the models and the framebuilder.

  4782   Thu Jun 2 23:10:10 2011 KojiUpdateElectronicsREFL11 test results (Re: REFL11 fixed)

The full characterization of REFL11 is found in the PDF.

Resonance at 11.062MHz
Q of 15.5, transimpedance 4.1kOhm
shotnoise intercept current = 0.12mA (i.e. current noise of 6pA/rtHz)

Notch at 22.181MHz
Q of 28.0, transimpedance 23 Ohm

Notch at 55.589MHz
Q of 38.3, transimpedance 56 Ohm


Attachment 1: REFL11_test.pdf
REFL11_test.pdf REFL11_test.pdf REFL11_test.pdf REFL11_test.pdf
  4783   Fri Jun 3 14:27:32 2011 KojiUpdateElectronicsPOP55 test results

The full characterization of POP55 is found in the PDF.

Resonance at 54.49MHz
Q of 2.5, transimpedance 241Ohm
shotnoise intercept current = 4.2mA (i.e. current noise of 37pA/rtHz)

Notch at 11.23MHz
Q of 2.4, transimpedance 6.2 Ohm

Notch at 110.80MHz
Q of 53.8, transimpedance 13.03 Ohm


Attachment 1: POP55_test.pdf
POP55_test.pdf POP55_test.pdf POP55_test.pdf POP55_test.pdf
  4784   Fri Jun 3 18:12:03 2011 steveUpdateComputersno PEM channels

AA filter box was removed and modified at 1Y7 today. The -5V power supply was current limited when I plugged it back in. It was removed for medical attention.

NO PEM channels available! because of this.


  4785   Sat Jun 4 15:26:04 2011 Larisa ThorneUpdateElectronicsSeismometer Box Update

 (continuation of this)


Here are the transfer function and noise plots of the seismometer box, using the op amps that are actually indicated on the original plan (THS4131, AD826). I added them to the LISO op amp library (can be found in /cvs/cds/caltech/apps/linux64/liso/filter/opamp.lib)

Next step is to compare the noise graph below to the seismic noise curve of the interferometer to verify that the seismometer box configuration won't affect the curve...

Attachment 1: SeisBoxLISO_transfer.pdf
Attachment 2: SeisBoxLISO_noise.pdf
  4786   Mon Jun 6 02:09:39 2011 ranaUpdateElectronicsPOY11 Rework Nearly Complete

I've finished tuning POY11 and it is now sitting on top of the analyzer waiting for Koji to test its noise.


  1. R2 has been switched from a 50 -> 110 Ohm R and a (29 Ohm | 47 pF) in parallel to it. This makes the gain of the MAX4107 be ~20 above 100 MHz and ~5 around 11 MHz. The high gain at high frequency makes it stable (squashes the 200 MHz oscillation) and the low gain at low frequency is to prevent saturation (the raw 11 MHz transimpedance is too high).
  2. There are two notches: 22.12 MHz and 55.3 MHz.
  3. The TEST IN input has been disabled since it wasn't useful.
  4. 107 Ohms inserted into between the U11 output and the TSENSE feedthrough. This is to prevent oscillations when driving the long Dsub cable. This needs to be done on all Gold Box RFPDs.
  5. R4 -> 50 Ohms.
  6. Had trouble tuning this to get the resonance at 11.06 MHz. This turned out to be the parallel inductance coming from L3 (previously 1.45 uH) whereas we needed a total inductance of ~1.6 uH. So I changed L3 to 33 uH to get it to be negligible compared to 1.7 uH at 11 MHz. This needs to be considered for all the 11 MHz diodes.


Attachment 1: 777.png
  4787   Mon Jun 6 16:44:34 2011 KojiUpdateElectronicsPOY11 tested

The full characterization of POY11 is found in the PDF.

Resonance at 11.03MHz
Q of 7.6, transimpedance 1.98kOhm
shotnoise intercept current = 0.17mA (i.e. current noise of 7pA/rtHz)

Notch at 21.99MHz
Q of 56.2, transimpedance 35.51 Ohm

Notch at 55.20MHz
Q of 48.5, transimpedance 37.5 Ohm


Attachment 1: POY11_test.pdf
POY11_test.pdf POY11_test.pdf POY11_test.pdf POY11_test.pdf
  4789   Mon Jun 6 17:28:31 2011 steveUpdateComputersstill, no PEM channels


AA filter box was removed and modified at 1Y7 today. The -5V power supply was current limited when I plugged it back in. It was removed for medical attention.

NO PEM channels available! because of this.


 D68L8EX-850Hz filter chips were removed and bypassed-shorted as Rana's entry on March 17, 2006 in old elog.

This unit is still has a short somewhere.

Attachment 1: P1070846.JPG
  4790   Mon Jun 6 18:29:01 2011 Jamie, JoeUpdateCDSCOMPLETE FRONT-END REBUILD (WITH PROBLEMS (fixed))

Today Joe and I undertook a FULL rebuild of all front end systems with the head of the 2.1 branch of the RCG.  Here is the full report of what we did:

  1. checked out advLigoRTS/branches/branch-2.1, r2457 into core/branches/branch-2.1
  2. linked core/release to branches/branch-2.1
  3. linked in models to core/release/src/epics/simLink using Joe's new script (userapps/release/cds/c1/scripts/link_userapps)
  4. remove unused/non-up-to-date models:
  5. c1dafi.md
  6. modified core/release/Makefile so that it can find models:
  7. --- Makefile	(revision 2451)
    +++ Makefile (working copy)
    @@ -346,7 +346,7 @@
    #MDL_MODELS = x1cdst1 x1isiham x1isiitmx x1iss x1lsc x1omc1 x1psl x1susetmx x1susetmy x1susitmx x1susitmy x1susquad1 x1susquad2 x1susquad3 x1susquad4 x1x12 x1x13 x1x14 x1x15 x1x16 x1x20 x1x21 x1x22 x1x23

    #MDL_MODELS = $(wildcard src/epics/simLink/l1*.mdl)
    -MDL_MODELS = $(shell cd src/epics/simLink; ls m1*.mdl | sed 's/.mdl//')
    +MDL_MODELS = $(shell cd src/epics/simLink; ls c1*.mdl | sed 's/.mdl//')

    World: $(MDL_MODELS)
  8. removed channel files for models that we know will be renumbered
    • For this rebuild, we are also building modified sus models, that are now using libraries, so the channel numbering is changing.
  9. make World
    • this makes all the models
  10. make installWorld
    • this installs all the models
  11. Run activateDQ.py script to activate all the relevant channels
    • this script was modified to handle the new "_DQ" channels
  12. make/install new awgtpman:
  13. cd src/gds
    cp awgtpman /opt/rtcds/caltech/c1/target/gds/bin
  14. turn off all watchdogs
  15. test restart one front end: c1iscex

    The c1iscex models (c1x01 and c1scx) did not come back up.  c1x01 was running long on every cycle, until the model crashed and brought down the computer.  After many hours, and with Alex's help, we managed to track down the issue to a patch from Rolf at r2361.  The code included in that patch should have been wrapped in an "#ifndef RFM_DIRECT_READ".  This was fixed and committed to branches/branch-2.1 at r2460 and to trunk at r2461.

  17. update to core/branches/branch-2.1 to r2460
  18. make World && make installWorld with the new fixed code
  19. restarted all computers
  20. restart frame builder
  21. burt restored to 8am this morning
  22. turned on all watchdogs

Everything is now green, and things seem to be working.  Mode cleaner is locked.  X arm locked.


  4791   Mon Jun 6 22:41:22 2011 ranaUpdateSUSSwitching problem in SUS models

Some weeks ago, Joe, Jamie, and I reworked the ETMY controls.

Today we found that the model rebuilds and BURT restores have conspired to put the SUS damping into a bad state.

1) The FM1 files in the XXSEN modules should switch the analog shadow sensor whitening. I found today that, at least on ETMY and ETMX, they do nothing. This needs to be fixed before we can use the suspensions.

2) I found all of the 3:30 and cts2um buttons OFF AGAIN. There's something certainly wrong with the way the models are being built or BURTed. All of our suspension tuning work is being lost as a consequence. We (Joe and Jamie) need to learn to use CONLOG and check that the system is not in a nonsense state after rebuilds. Just because the monitors have lights and the MEDM values are fluctuating doesn't mean that "ITS WORKING". As a rule, when someone says "it seems to work", that basically means that they have no idea if anything is working.

3) We need a way to test that the CDS system is working...

Attachment 1: a.pdf
  4793   Tue Jun 7 11:39:27 2011 JamieUpdateSUSNo binary output module in ETMY

1) The FM1 files in the XXSEN modules should switch the analog shadow sensor whitening. I found today that, at least on ETMY and ETMX, they do nothing. This needs to be fixed before we can use the suspensions.

Joe discovered today that ETMY in fact has no binary output module at all, so there is actually no digital control of the whitening filters at ETMY.

We suspect that the ETMY binary output module was maybe harvested to put in the LSC rack, but we're not sure.

We found a spare binary output adapter pcb, which I will try to assemble into a module to install in ETMY.

This does not explain what's going on with ETMX, though.  ETMX has a binary output module, that appears to be properly hooked up.  I'll try to debug what's going on there as well.

In the mean time, I've removed the ETMX binary output module to use as a reference for putting together another identical module for ETMY.

  4794   Tue Jun 7 16:11:09 2011 steveUpdateCamerasITM camera lenses changed

Computar  75-12.5 zooms were installed for closer look at the resonant spots.  Their alignment and focus needs more loving adjustment.

Atm 1, ITMX  (  it was 10-40 mm Tamron before )

Atm 2, ITMY  ( it was 12mm wide angle showing the towers  before )

Attachment 1: P1070865.JPG
Attachment 2: P1070860.JPG
  4795   Wed Jun 8 16:41:48 2011 valeraUpdateASSX and Y arm dither alignment status

 The current status of the dither alignment system:

- Both Xarm and Yarm alignment are working. The scripts are: scripts/autoDither/alignX(Y). Each script sets up the respective arm, turns on the dither lines and servos for 66 sec, offloads the control signals to TM alignment biases and PZT sliders in case of  Yarm, and to TM and BS alignment biases in case of Xarm, and finally turns off and clears the servo filters and turns off the dither lines.

- Jammie witnessed the final tests of both scripts - both X and Y arm power went up from 0.6-0.7 to close to 1 and the AS beam became symmetric. Also Jammie wanted me to leave the ETMY oplev in its current non-nominal but more stable state i.e. the oplev signals go to the ADC from the D010033 card not the D020432 one. The scripts can now run from the CONFIGURE medm screen.

- Both arms use signals derived from modulating ITM and ETM in pitch and yaw dofs and demodulating the arm power (TRX or TRY) and the cavity length signal (AS55I). The Yarm actuation has 8 dofs - pitch and yaw of the ITM, ETM, and two input beam PZTs so all the sensed dofs are controlled. The Xarm actuation has only 6 dofs - pitch and yaw of the ITM, ETM, and BS. The Xarm servo is set up to servo the beam position on the ETMX and the relative alignment of the cavity and the input beam. The ITMX spot position is unconstrained and provides the null test. The residual displacement on the ITMX is 0.2-0.3 mm in yaw and 0.9-1.0 mm in pitch. The I phases of the beam centering lockins, which are also the error points of corresponding DOF filters, are calibrated in mm by unbalancing the TM coils by known amount. The attached snap shot of the medm screen now has both X and Y arm calibrated beam spot positions and uncalibrated input beam indicators. The input beam angle and position signals can/should be calibrated by tapping the signals digitally and applying the proper matrix transformation - this will require the model change.

- Currently there is no lock loss catching in the model. We should add a trigger on arm power (or an equivalent mechanism) to turn off the inputs to prevent the spurious inputs.

Attachment 1: BeamPositionIndicators.png
  4796   Wed Jun 8 22:48:09 2011 ranaUpdateCamerasITM camera lenses changed

I focused these lenses so that we could get a clean image of the mirrors and the OSEMs.

Our goal is to have an image where the optic diameter almost fills the entire monitor. We want the focus to be adjusted for the YAG beam (which is almost the same as focusing for the OSEMs). This will NOT produce a nice image of the cage using visible light, but that is just fine.

When Justin Garofoli was here he found a nice lens combo that did the job, so if anyone can find his old email or elog, lets just go back to that.

For now, we do not need a camera/lens system to focus very tightly on the center of the optic.

  4797   Wed Jun 8 23:17:25 2011 kiwamuUpdateLSCDRMI output matrix diagonalization

Approximately two weeks ago I diagonalized the LSC output matrix for the DRMI locking.

Since actuation on the position of BS changes not only MICH but also PRC and SRC, we needed to diagonalize the output matrix.


- What I did :

 (1) The DRMI was locked. At this point PRC, MICH and SRC was controlled by PRM, BS and SRC actuators respectively.

 (2) I injected excitation signal on C1:LSC-MICH_EXC by awg. The excitation was at about 200 Hz, which is above the UGF of all the LSC loops.

    At this point the excitation only shakes the position of BS.

 (3) I looked at spectra of REFL11_I, AS55_Q, AS55_I, that were used to sense PRC, MICH and SRC respectively.

   At the beginning I was able to see the peak due to the excitation in those spectra. This means BS shakes the other DOFs (i.e. PRC and SRC) as well as MICH.

 (4) To minimize the coupling from MICH to PRC (or SRC), I tuned a number on an element of the output matrix, which transfers the signal from MICH to PRM (or SRM).

   This business was done by looking at the peak on REFL11_I (or AS55_I) and minimizing it. Since this technique was too naive the tuning was done only in second decimal place.


  4798   Thu Jun 9 10:38:30 2011 steveUpdatePSLPMC needs help

The PMC is losing power.

Attachment 1: pmcnothp.jpg
  4799   Thu Jun 9 12:21:07 2011 kiwamuUpdatePSLRe : PMC needs help

Nulling the slow actuation offset fixed the issue. Now PMC is back to normal.


The reflected beam on the CCD was quite symmetric (it looked very TEM00 mode !) for some reasons, I somehow suspected the mode matching to PMC.

One possibility I thought of was the laser temperature because it could change the laser spatial mode.

So I looked at the slow actuation offset on the FSS screen and found it was at -4.0 which sounds somewhat big.

Then I zeroed the offset by the slider and relocked PMC.

Then the spatial pattern of the reflected beam became usual (i.e. junk light looking) and the transmitted light wet up to 0.83 which is normal.

Quote from #4798

The PMC is losing power.


  4800   Thu Jun 9 16:18:03 2011 josephbUpdateCDSSecond trends only go back 12 days

While answering a quick question by Kiwamu, I noticed we only had second trends going back to 99050000 GPS time, May 27th 2011. 

Trends (I thought) were intended to be kept forever, and certainly longer than full data, which currently goes back several months.

Jamie will need to look into this.

  4802   Thu Jun 9 20:10:38 2011 kiwamuUpdateSUSETMY whitening filter : all off

I checked the state of the whitening filters for the ETMY shadow sensors.

Result : They've been OFF  (i.e. flat response).


(measurement and setup)

 I measured the transfer functions of the whitening board (D000210) by looking at the signal before and after the whitening stage.

 The whitening board handles five signals; UL, UR, LR, LL and SD, and there are five single-pin lemo outputs for each signal on the front panel.

A good thing on those lemo monitors is that their signals are monitored before the whitening stages.

Rana suggested me to use these signals for the denominator of the transfer functions and consider the sensor signals as excitation signals.

So I plugged those signals into extra ADC channels via an AA-board and measured the transfer functions.

In the measurement the coherence above 4 Hz was quite small while the suspension was freely swinging.

Therefore I had to excite the ETMY suspension by putting random noise in a frequency band from 5 Hz to 35 Hz to obtain better coherence.



 The response is flat over frequency range from ~ 0.2 Hz to ~40 Hz, see the plot below. 

According to the spectrum of each signal the measurements above 10 Hz are just disturbed by the ADC noise.

If the whitening filters are ON, a pole and zero are expected to appear at 30 Hz and 3 Hz respectively according to the schematic, but no such features.



  4803   Fri Jun 10 12:02:10 2011 ranaUpdateCDSSecond trends only go back 12 days


While answering a quick question by Kiwamu, I noticed we only had second trends going back to 99050000 GPS time, May 27th 2011. 

Trends (I thought) were intended to be kept forever, and certainly longer than full data, which currently goes back several months.

Jamie will need to look into this.

 Our concept is to keep second trends for 1-2 months and minute trends forever. The scheme that Alan had worked out many years ago had it such that we could look back to 1998 and that the minute trends would be backed up somehow.

If its not working, we need to get Alan's help to recover the previous configuration.

  4804   Fri Jun 10 12:04:57 2011 JenneUpdateRF SystemBad RF connections!!

I am in the process of calibrating AS55's shot noise, and I noticed that the AS55 PD input to the demod board was only finger-tight.  I then checked all of the other SMA connections in the set of RF PD demod boards, and found several more that were loose, including all of the REFL55 connections.  This is no good!!!! RF connections need to be tightened!  I went through and tightened all of the offending connections with my personal Snap-on SMA wrench. 

  4805   Fri Jun 10 14:50:37 2011 KojiUpdateLSCNew LSC code installed

[Koji Jamie]

The new c1lsc code has been installed. The LSC screens have also been updated (except for ASS screen).

The major changes are:

1. Naming of the RFPD channels. Now the PD signals were named like:

REFL11_I_IN1, REFL11_I_IN2, REFL11_I_OUT ....

instead of REFL11I_blah

2. NREFL11, etc has been removed. We now have the official error signals
named like


We can't use the name "REFL11_I" for the error signal as this name is
occupied by the name of the filter module.

  4806   Fri Jun 10 18:49:40 2011 kiwamuUpdateIOOIntensity Noise after the MC

Last night the relative intensity noise (RIN) of the beam after MC was measured.

It looks like the RIN is dominated by the motion of the MC mirrors, possibly the angular motions because we don't have any angular stabilization servos.

Suresh will estimate the contribution from the MC mirrors' angular motion to the RIN in order to see if this plot makes sense.



 The spectrum below 30 Hz seems to be dominated by the motion of the MC suspensions because it very resembles the spectra of those.

Above 30 Hz the spectrum becomes somehow flat, which I don't know why at the moment.

A rough estimation of the shot noise gave me a level of 10^{-9} RIN/sqrtHz, which is way below the measured spectrum.




 All of the suspended mirrors were intentionally misaligned except for the MC mirrors and PRM to avoid interference from the other optics.

In this setup it allows us to measure the intensity noise of the laser which is transmitted from MC.

The beam transmitted from MC is reflected by PRM and finally enters into the REFL11 RFPD.

The DC signal from the RFPD was acquired at C1:LSC-REFL_DC_DQ as the laser intensity.

As well as the RIN measurement I took a spectrum when the beam is blocked by a mechanical shutter on the PSL table.

This data contains the dark noise from REFL11 and circuit noise from the whitening, AA board and ADC. It is drawn in black in the plot.

The cut off at 15 Hz is possibly due to the digital unwhitening (two poles at 15 Hz and two zeros at 150 Hz) filter to correct the analog whitening filter.

  4807   Fri Jun 10 20:23:56 2011 Larisa ThorneUpdateElectronicsSeismometer Box Update/graphs

 (continuation of this)


The noise graphs relating total noise of the Seismometer circuit (GURALP stuff) to the LIGO seismic noise curve have been completed started.



I apparently harbor hate towards Matlab (you may have notice I do everything in Mathematica)....I will try to change my ways  DX

Attachment 1: SeisNoiseGraphs.jpg
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