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ID Date Author Type Category Subject
  4585   Fri Apr 29 03:39:49 2011 KojiSummaryLSCCavity lengths

I tried the idea that the PRC can resonate f1 and f2 at the same time if the arm gives the reflection phase to f1 and f2 with the ratio of 1 vs 5.

The details are described on wiki. The point is this removes all of the PRC/SRC/asymmetry mumbo jumbo.

The calculated cavity lengths for f_mod of 11.065399MHz are:

  • Arm Length: 37.7974 [m]

  • PRC Length: 6.7538 [m]

  • SRC Length: 5.39915 [m]

  • Asymmetry (lx-ly): 0.0342 [m]


Here is the actual values derived from the photos.

  • Arm Length: 37.54 [m] (0.26m too short)

  • PRC Length: 6.760 [m] (6mm too long)

  • SRC Length: 5.415 [m] (16mm too long)

  • Asymmetry (lx-ly): 0.0266 [m] (8mm too long)

  4584   Thu Apr 28 22:38:38 2011 AidanUpdateGreen LockingElectronics schematic for vertex beatbox

 With some assistance from Kiwamu and Koji, I've drawn up the electronics design for the Beat Box for the vertex green locking. The Omingraffle schematic is posted on the Green Locking Wiki page. It's also attached below. Some final touches are necessary before we can Altium this up.

 Attachment 1: Schematic of beatbox

Attachment 2: Front and back panel designs.

Attachment 1: Canvas_1.png
Canvas_1.png
Attachment 2: Canvas_2.png
Canvas_2.png
  4583   Thu Apr 28 16:12:19 2011 josephb, jamieUpdateCDSNew CDS model SVN

New SVN

We are now using the LIGO CDS SVN for storing our control models.

The SVN is at:

https://redoubt.ligo-wa.caltech.edu/websvn/

The models are under cds_user_apps, then trunk, then approriate subsystem (ISC for c1lsc for example), c1 (for caltech 40m), then models.

We have checked out /cds_user_apps to /opt/rtcds/.

So to find the c1lsc.mdl model, you would go to /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1lsc.mdl

This SVN is shared by many people LIGO, so please follow good SVN practice.  Remember to update models ("svn update") before doing commits.  Also, after making changes please do an update to the SVN so we have a record of the changes.

New Practices

We are creating soft links in the /opt/rtcds/caltech/c1/core/advLigoRTS/src/epics/simLink/ to the models that you need to build.  So if you want to add a new model, please add it to the cds_users_apps SVN in the correct place and create a soft link to the simLink directory.

lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1sus.mdl -> /opt/rtcds/cds_user_apps/trunk/SUS/c1/models/c1sus.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1sup.mdl -> /opt/rtcds/cds_user_apps/trunk/SUS/c1/models/c1sup.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1spy.mdl -> /opt/rtcds/cds_user_apps/trunk/SUS/c1/models/c1spy.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1spx.mdl -> /opt/rtcds/cds_user_apps/trunk/SUS/c1/models/c1spx.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1scy.mdl -> /opt/rtcds/cds_user_apps/trunk/SUS/c1/models/c1scy.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1scx.mdl -> /opt/rtcds/cds_user_apps/trunk/SUS/c1/models/c1scx.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1mcs.mdl -> /opt/rtcds/cds_user_apps/trunk/SUS/c1/models/c1mcs.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1x05.mdl -> /opt/rtcds/cds_user_apps/trunk/CDS/c1/models/c1x05.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1x04.mdl -> /opt/rtcds/cds_user_apps/trunk/CDS/c1/models/c1x04.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1x03.mdl -> /opt/rtcds/cds_user_apps/trunk/CDS/c1/models/c1x03.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1x02.mdl -> /opt/rtcds/cds_user_apps/trunk/CDS/c1/models/c1x02.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1x01.mdl -> /opt/rtcds/cds_user_apps/trunk/CDS/c1/models/c1x01.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1rfm.mdl -> /opt/rtcds/cds_user_apps/trunk/CDS/c1/models/c1rfm.mdl
lrwxrwxrwx 1 controls controls      55 Apr 28 14:41 c1dafi.mdl -> /opt/rtcds/cds_user_apps/trunk/CDS/c1/models/c1dafi.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1pem.mdl -> /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1pem.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1mcp.mdl -> /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1mcp.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1lsp.mdl -> /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1lsp.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1lsc.mdl -> /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1lsc.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1ioo.mdl -> /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1ioo.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1gpv.mdl -> /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1gpv.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1gfd.mdl -> /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1gfd.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1gcv.mdl -> /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1gcv.mdl
lrwxrwxrwx 1 controls controls      54 Apr 28 14:41 c1ass.mdl -> /opt/rtcds/cds_user_apps/trunk/ISC/c1/models/c1ass.mdl

  4582   Thu Apr 28 15:31:36 2011 kiwamuUpdateIOOMC PDH lock : readjustment of demodulation phase

Since Suresh has installed the RF source box and changed the cable configuration somewhat,

the demodulation phase for the MC locking became off by about 10 degree.

I changed the length of some cables and obtained a good demodulation phase by the same technique as Suresh and Koji did before (see here for detail).

I maximized the Q signal. The lock of the MC looks healthy.

DSC_2975_ss.jpg

Quote from #4578

RF Source box has been mounted in the 1X2 rack. 

  4581   Thu Apr 28 12:25:11 2011 josephbUpdateCDSFurther adventures in Hyper-threading

First, I disabled front end starts on boot up, and brought c1sus up.  I rebuilt the models for the c1sus computer so they had a new specific_cpu numbers, making the assumption that 0-1 were one real core, 2-3 were another, etc.

Then I ran the startc1SYS scripts one by one to bring up the models.  Upon just loading the c1x02 on "core 2" (the IOP), I saw it fluctuate from about 5 to 12.  After bringing up c1sus on "core 3", I saw the IOP settle down to about 7 consistently.  Prior to hyper-threading it was generally 5. 

Unfortunately, the c1sus model was between 60 and 70 microseconds, and was producing error messages a few times a second

[ 1052.876368] c1sus: cycle 14432 time 65; adcWait 0; write1 0; write2 0; longest write2 0
[ 1052.936698] c1sus: cycle 15421 time 74; adcWait 0; write1 0; write2 0; longest write2 0

Bringing up the rest of the models (c1mcs on 4, c1rfm on 5, and c1pem on 6), saw c1mcs occasionally jumping above the 60 microsecond line, perhaps once a minute.   It was generally hovering around 45 microseconds.  Prior to hyper-threading it was around 25-28 microseconds.

c1rfm was rock solid at 38, which it was prior to hyper-threading.  This is most likely due to the fact it has almost no calculation and only RFM reads slowing it down.

c1pem continued to use negligible time, 3 microseconds out of its 480.

I tried moving c1sus to core 8 from core 3, which seemed to bring it to the 58 to 65 microsecond range, with long cycles every few seconds.

 

I built 5 dummy models (dua on 7, dub on 9, duc on 10, dud on 11, due on 1) to ensure that each virtual core had a model on it, to see if it helped with stabilizing things.  The models were basically copies of the c1pem model.

Interestingly, c1mcs seemed to get somewhat better and only taking to 30-32 microseconds, although still not as good as its pre-hyper-threading 25-28.  Over the course of several minutes it was no longer having a long cycle.

c1sus got worse again, and was running long cycles 4-5 times a second.

 

At this point, without surgery on which models are controlling which optics (i.e. splitting the c1sus model up) I am not able to have hyper-threading on and have things working.  I am proceeding to revert the control models and c1sus computer to the hyper-threading state.

 

 

  4580   Thu Apr 28 10:53:50 2011 josephbUpdateCDSAdventures in Hyper-threading

What was done:

1) Turn off MC1, MC2, MC3, BS, ITMX, ITMY, PRM, SRM watchdogs.

2) Turn c1sus computer off (sudo shutdown now)

3) Go connect monitor and keyboard to c1sus.  Turn c1sus on.

4) Hit "del" key at the right time to go to setup (BIOS).

5) Go to BIOS advanced tab, CPU options, enable Multi-threading.

6) Hit F10 to save and let the computer continue booting.

What went wrong:

Once c1sus was up, I noticed several red lights and dead keep alives for the c1sus models.

Typing dmesg on c1sus revealed many messages like:

[  107.583420] c1x02: cycle 33737 time 20; adcWait 10; write1 0; write2 0; longest write2 0
[  107.583771] c1x02: cycle 33760 time 19; adcWait 11; write1 0; write2 0; longest write2 0

This indicates the Input/Output Processor (IOP) is not completing its duties within the 15 microseconds (1/64 kHz) that it has.  These lines indicate its take 20 or 19 microseconds.  (I saw messages ranging from 16 to 22 microseconds).

So this seems to agree with Rolf's observations that hyperthreading can cause a 5-10 microsecond increase in computation time.

So the next thing to do is modify which core the codes are running on, and try to get them paired up on the same physical core.

  4579   Thu Apr 28 07:14:34 2011 SureshUpdateRF SystemRF Distribution box installed

RF Distribution box has been mounted in the 1Y2 rack and is ready for use.

 

P4280066.JPG

The box receives 11 and 55 MHz Demod Signals from the RF source located in the 1X2 rack.

  4578   Thu Apr 28 06:46:30 2011 SureshUpdateRF SystemRF Source installed

RF Source box has been mounted in the 1X2 rack. 

P4280064.JPG

 

Heliax cables have been directly attached to the box and anchored on the side of the 1X2 rack.  Here is a list of Helix cables which have been connected so far.

 

Cables old name New name From -> To
1 133 MHz 11 Mhz Demod 1X2 to 1Y2 rack
2 199 MHz 55 MHz Demod 1X2 to 1Y2 rack
3 166 EOM 11 MHz EOM 1X2 to PSL table
4 33 EOM 55 MHz EOM 1X2 to PSL table
5 REFL 33 AS11 AS table to 1Y2

 

  4577   Wed Apr 27 21:19:25 2011 kiwamuUpdateLSCLSC whitening for PD1-4

On the back side of 1Y2 rack I found a cable, CAB-1X2-LSC_7, which is supposed to be connected to the whitening filter was disconnected.

I plugged it back and confirmed that the whitening filter is under control of EPICS.

Now all the gain sliders seem to be working because I can change the amplitude of signals with the sliders.

 

(method)

  To check if the gain sliders are working or not, I intentionally disconnected all the inputs to the whitening filter.

Then I brought a gain slider of interest to the maximum. Due to the big gain I was easily able to see noise lying above ADC noise.

Also if the gain slider is 0 dB, which is the minimum value, the spectrum becomes just ADC noise.

In this way I checked all the gain sliders from PD1 to PD4. The picture below is just an example screenshot when I was doing this test.

Note that each filer is designed to have two poles at 150 Hz and two zeros at 15 Hz.

Screenshot-1.png

Quote from #4570

While checking whitening filters on the LSC rack, I found some epics controls for the whitening looked not working.

So I powered two crates off : the top one and the bottom one on 1Y3 rack.

These crates contain c1iscaux and c1iscaux2. Then powered them on. But it didn't solve the issue.

  4576   Wed Apr 27 21:08:08 2011 ranaUpdateLSCAS11

I worked on AS_11 today. Its ready for its noise / optical gain calibrations. I have left it on Suresh's desk.

AS11.png

This was one of the 24.5 MHz Black Box (Ben Abbott) style RFPDs rescued from LLO. The tunable inductor that was installed was too small to get the frequency down to 11 MHz and so I swapped in one of the shielded, ferrite core ones from our '7mm' CoilCraft kit. It had a range of 1.2 - 1.8 uH according to the datasheet.

I wasn't able to simulataneously get the peak at 11.06 MHz and the notch at 59.3 MHz and so I took Koji's advice and tuned the peak best. The plot above shows how the notch is slightly off. I think its not a problem; to get it better we would have to change out the inductor for the "2-omega" notch, but I was too lazy. The thinking is that its more important to have the gain be symmetric around the signal readout frequency so as to not imbalance the audio sidebands.

Since this one is going to be AS_11, we think that the 22 MHz signal will be tiny: the transmission of the 11 MHz sidebands to the dark port is small. If we later want to put in a 22 MHz notch anyway, there is space to do this via the 'active notch' pads around the MAX4107.

For the above plot, I used the Jenne laser. The DC output of the PD was ~30 mV (~0.6 mA). The RF drive to the laser was -10 dBm: no saturations. I have calibrated out the cable responses, but not using the 1811 setup, so the absolute calibration has yet to be done.

Also, it needs some new stickers. It would be handy if someone can figure out how to get some sheets of stickers that we can put into the printer. Then we can laser printer all of the data onto the stickers and stick them to the RFPD box.

  4575   Wed Apr 27 20:14:16 2011 AidanSummaryelogRestarted with script ...
  4574   Wed Apr 27 18:14:48 2011 kiwamuUpdateLSCpreparation for DRMI locking : RF status

RF_Work_Status.png

POX11 (see this entry) is now listed as REFL11 (on the very top row).

We will rename POY11 to POP11 for DRMI locking.

The files are on https://nodus.ligo.caltech.edu:30889/svn/trunk/suresh/40m_RF_upgrade/.

  4573   Wed Apr 27 17:38:01 2011 kiwamuUpdateElectronicsRe : AS55 demod board with new 90 deg splitter : healthy

relativephase.png

Figure.1  I-Q relative phase measurement as a function of LO power.

 Blue curve : relative phase of AS55 that I have modified today (#4572).

 Red curve : relative phase of AS11 that I had modified a week ago (#4554). Just for comparison.

 The relative phase of AS55 agrees approximately what we expected according to the datasheet of PSCQ-2-51W. We expected 85 degree.

 

IQamplitude.png

Figure.1  I-Q amplitude imbalance as a function of LO power.

From - 5 dBm to 5 dBm in LO power the imbalance is within 3 %.

But the precision of the measurement is also about 2 % (because I used an oscilloscope). Even so the imbalance is still good.

Quote from #4572

Some plots will be posted later.

 

  4572   Wed Apr 27 15:34:38 2011 kiwamuUpdateElectronicsAS55 demod board with new 90 deg splitter : healthy

A new 90 deg splitter, PSCQ-2-51W, has been installed on another demod board called AS55.

It shows a reasonably close 90 degree separation between the I and Q signals at 55 MHz with various LO and RF power.

So far we have ordered only three PSCQ-2-51Ws for test. Now we will order some more for the other demodulators.

 Some plots will be posted later.

  4571   Tue Apr 26 22:56:35 2011 ZachUpdateelogrestarted

 with script

  4570   Tue Apr 26 22:56:01 2011 kiwamuUpdateLSCc1iscaux2 and c1iscaux restrated

While checking whitening filters on the LSC rack, I found some epics controls for the whitening looked not working.

So I powered two crates off : the top one and the bottom one on 1Y3 rack.

These crates contain c1iscaux and c1iscaux2. Then powered them on. But it didn't solve the issue.

  4569   Tue Apr 26 22:03:49 2011 ranaUpdateElectronicsPOX_11 debugging

I used the Jenne AM laser to tune up the PD (used to be POX_11 but now is called REFL_11). In addition to the notch at 22 MHz, I have also put in a LC notch at 5*f = 55.3 MHz. The transfer function below shows the RF OUT of the PD v. the drive to the laser. I didn't divide out by the 1811 because its not on the EE bench.

MM7.png

 

  4568   Tue Apr 26 01:20:02 2011 ranaUpdateElectronicsPOX_11 debugging

The performance plots for POX_11 in the wiki are horrendous and the schematic is missing.

I opened up the box and found all kinds of horrors. There were multiple tunable parts and a flurry of excess nonsense.

The top 2 worst offenders:

1) The main tunable inductor was busted. I removed it and found that the coil was open. Too much indelicate soldering in its vicinity had melted the wire. Someone had put extra inductors and capacitors around it to make it seem as if the PD was working fine, but the noise performance was off by a factor of ~100.

2) The MAX4107 had a 1.4k series resistor. This make the output go through a 1450/50 voltage division which is not nice for the SNR. I removed it.

I then struggled for awhile to get a sensible response. It turned out that the TEST IN input was not giving me a sensible TF. Jenne and I fired the Jenne laser at it and found that the 11 MHz main resonance is there. In the morning I'll finish this off and post more results. I think its going to end up being fine.

We are going to have to take a careful look at all the RFPDs if this one is any indication...

  4567   Mon Apr 25 22:38:49 2011 kiwamuUpdateLSCprepration for DRMI : Y arm flashing
This week is going to be a recycled Michelson week.
As a preparation I did several things today :
 1. Alignment of the Y arm
 2. Alignment of PRM
 3. Checking of all the pick-off ports

 


 
(Y arm alignment)
 The idea to have the Y arm aligned is that : once we lock the Y arm we will be able to align the input PZTs using the Y arm as a reference.
 I tried aligning the Y arm and successfully made the Y arm flashing with IR. I can see it flashing on ITMY camera but no flashing on ETMY camera.
 
(PRM alignment)
PRM has been intentionally misaligned for the single arm green locking test.
I just confirmed that we can bring PRM back to a good alignment. Now we can see the central part is flashing too.
 
(picked-off beams)
I went checking through all the picked off beams to see if they are available or not.
POX : lost
POY : fine
POP : very clipped
POSRM : fine
  4566   Mon Apr 25 12:55:35 2011 AlastairBureaucracyComputerswiki?

Quote:

Quote:

40m wiki seems to have been down for quite a while now but I can't see any info in the elog about it.  Is there some ongoing problem?

 There was an email from Dave Barker about this.  They had to reorganize the DNS at LHO.  The URL that should be used is: http://blue.ligo-wa.caltech.edu:8000/40m

 Thanks Jamie, I've updated the links from the ATF wiki to reflect this.

  4565   Mon Apr 25 12:55:19 2011 JenneBureaucracyComputerswiki?

Quote:

Quote:

40m wiki seems to have been down for quite a while now but I can't see any info in the elog about it.  Is there some ongoing problem?

 There was an email from Dave Barker about this.  They had to reorganize the DNS at LHO.  The URL that should be used is: http://blue.ligo-wa.caltech.edu:8000/40m

 Nope.  I know I had the right address, and it was down for me too all weekend.  It's better now though.  blue.ligo-wa.caltech.edu was up though.

  4564   Mon Apr 25 11:58:37 2011 JamieBureaucracyComputerswiki?

Quote:

40m wiki seems to have been down for quite a while now but I can't see any info in the elog about it.  Is there some ongoing problem?

 There was an email from Dave Barker about this.  They had to reorganize the DNS at LHO.  The URL that should be used is: http://blue.ligo-wa.caltech.edu:8000/40m

  4563   Mon Apr 25 11:23:41 2011 AlastairBureaucracyComputerswiki?

40m wiki seems to have been down for quite a while now but I can't see any info in the elog about it.  Is there some ongoing problem?

119427.strip.gif

  4562   Sun Apr 24 21:37:40 2011 kiwamuUpdateIOOreview of triple resonant EOM : model looks fine

To design a new resonant EOM box I started reviewing the prototype that I've built.

As a part of reviewing I checked an important thing that I haven't carefully done so far :

I compared the measured input impedance with that of predicted from a circuit model. I found that they show a good agreement.

So I am now confident that we can predict / design a new circuit performance.


* * * (input impedance) * * *

 Performance of a resonant circuit is close related to its input impedance and hence, in other words, determined by the input impedance.

Therefore an investigation of input impedance is a way to check the performance of a circuit. That's why I always use impedance for checking the circuit.

The plot below is a comparison of input impedance for the measured one and one predicted from a model. They show a good agreement.

(Note that the input impedance is supposed to have 50 Ohm peaks at 11, 29.5 and 55 MHz.)
Input_impedance.png

 
* * * (circuit model) * * *

To make the things simpler I assume the following three conditions in my model:

 1. inductor's loss is dominated by its DC resistance (DCR)

 2. capacitor's loss is characterized only by Q-value

 3. Transformer's loss is dominated by DCR and its leakage inductance

All the parameters are quoted from either datasheet or my measurement. The model I am using is depicted in the schematic below.

Basically the Q-vaules for the capacitors that I used are quite low. I think higher Q capacitors will improve the performance and bring them to more 50 Ohm.

EOMcircuitmodel.png
 

  4561   Fri Apr 22 12:07:38 2011 josephb, steveUpdateCDSRemoved hanging D-sub to SCSI in 1X2

Problem:

Way back, Jay had D-sub to SCSI adapters made to adapt our existing Sander box AA filters to the new SCSI based IO chassis.  However, these did not fit inside the box.

At the time, we simply left the cards outside hanging, which was a hack and needed to be replaced.

Solution:

Steve modified a black AA filter box so that it could fit the D-sub to SCSI adapter board on it, plus strain relief the SCSI cable, rather than let it hang.  The back of the box was cut, and an extending piece of metal attached to the bottom of the box.  The adapter board was screwed into the box, the SCSI plugged in, then the SCSI cable is clamped to the extending metal as well.

This modification will be propagated to the 3 remaining AA filter boards using the D-sub to SCSI adapter.

  4560   Fri Apr 22 11:08:50 2011 kiwamuUpdateLSCdemod board AS11 : amplitude imbalance

Amplitude imbalance between I and Q in a demod board, AS11, with the new 90 deg splitter was measured.

It shows roughly 10% amplitude imbalance when the LO power is in a range from 0 to 5 dBm. Not so bad.

 

  With the handmade coil there used to be a huge imbalance (either I or Q goes to zero volt while the other keeps about 1 V rms) as the LO power decreases.

But with the new 90 deg splitter now there are no more such a huge imbalance.

The remaining 10 % imbalance possibly comes from the fact that we are using ERA-5 in each I and Q path. They may have such gain imbalance of 10%.

We should check the ERA-5 gains so that we can confidently say ERA-5 causes the amplitude imbalance.

Then our plan replacing the ERA-5s (see here) will sound more reasonable.

IQamplitude.png

 

Quote from #4555

The new 90 deg splitter works better.

 I will also measure amplitude unbalances between I and Q.

 

  4559   Fri Apr 22 10:28:22 2011 ranaUpdateRF SystemRF Source Harmonics
You should be able to resolve the other harmonics by decreasing the IF BW or RBW on the analyzer. Even though
they're OK, its useful to have the final measurement of all of them in some kinds of physical units (like dBm, but
not dBm/Hz or dB or dBcubits).
  4558   Fri Apr 22 09:25:43 2011 SureshUpdateRF SystemRF Source: Temperature sensor relocated

RF Amp operating temperature

Earlier measurement reported by Alberto in LIGO-T10004-61-v1 based on the LM34 temperature sensor were lower than that shown by placing a calibrated thermocouple sensor directly on the heat sink by about 5deg C. The difference probably arose because the LM34 was located on a separate free-hanging copper sheet attached to the RF Amp by a single screw, resulting in a gradient across the copper strip.   I tried to move the LM34 which was glued down, but broke the leads in the process.  I then replaced it with another one mounted much closer to the heat sink and held it down with a copper-strip clamp.  There is no glue involved and there is heatsink compound between the flat surface of the LM34 and the heatsink.  Picture attached. 

  The picture also shows the new filters which have been put in place to reduce the harmonics.  Note that the SBP-10.7 which was to go on the 11 MHz Demod output is located much farther upsteam due to space constraints.

P4220056.JPG

  4557   Fri Apr 22 09:05:53 2011 SureshUpdateRF SystemRF Source Harmonics
As seen in the previous measurement the first harmonic of both the 11 MHz and 55 MHz outputs are about 30dB
higher than desired.  In an attempt to attenuate these and higher harmonics I introduced SBP-10.7 filters into
the 11MHz outputs and SLP-50 filters into the 55 MHz outputs.
Then I measured the height of the harmonics again and found that they were suppressed as expected.  Now harmonic
at 22 MHz is 58dB lower than the 11 MHz fundamental.  And the 110 MHz is lower by 55 dB compared to the 55 MHz
fundamental.  None of the higher harmonics are seen => they are below 70dB

SLP-50 has an insertion loss(IL) of 4.65 dB and Return Loss(RL) of 3dB.  It would be better to use SBP-60
(IL=1.4 dB and RL=23dB)

The filter on the 11 MHz lines is okay. The SBP-10.7 has IL=0.6 dB and RL=23 dB.
  4556   Fri Apr 22 02:10:53 2011 ZachUpdateelogrestarted

Restarted the elog with the script.

  4555   Thu Apr 21 21:46:22 2011 kiwamuUpdateLSCdemod board : new 90 deg splitter

A less LO power dependence on the relative phase was found. The new 90 deg splitter works better.

From -3 dBm to 10 dBm in LO power, the relative phase is within 90 +/- 5 deg.

As a comparison I plot the phase that I measured when the handmade coil had been there (green curve in the plot).

relativephase.png

 

 I will also measure amplitude unbalances between I and Q.

Quote from #4554

A 90 degree splitter, PSCQ-2-51W, has arrived today and I installed it on a demod board called AS11.

Results of the I-Q phase measurement with the new splitter will be reported soon.

 

 

  4554   Thu Apr 21 21:24:41 2011 kiwamuUpdateLSCdemod board : new 90 deg splitter

A new 90 degree splitter, PSCQ-2-51W, has arrived today and I installed it on a demod board called AS11.

Results of the I-Q phase measurement with the new splitter will be reported soon.

 

 * Picture 1 = before removal of the handmade coil

 * Picture 2 = after removal of the coil and the associated capacitors

 * Picture 3 = after soldering PSCQ-2-51-W

DSC_2949_ss.jpg

DSC_2951.JPG

DSC_2952_ss.jpg

Quote from #4358

 First of all we will replace the home-made 90 degree splitter (see this entry) by a commercial splitter, PSCQ-2-51-W+ from Mini circuit. This is the step 1 basically.

  4553   Thu Apr 21 15:20:46 2011 steveUpdatePEMPSL enclosure work today

Quote:

The east side window guides  will be replaced by one long U-channel. There will be drilling into 2x2 steel frame. It should be done by 2pm today

This should remove the jerking motion of windows hitting the individual guides.

 The installation went smoothly. There will be no more banging the doors into  guides on the east side.

Atm2 showing the west side as is today

Attachment 1: P1070558.JPG
P1070558.JPG
Attachment 2: P1070560.JPG
P1070560.JPG
  4552   Thu Apr 21 15:03:29 2011 steveUpdateComputersjuction board finds home

The anti aliasing box was opened up at the back to accommodate the junction board and the SCSI cable towards the ADC. Aluminum plate was attached to the bottom to hold the strain relief clamp.

Three more hanging junction cards will be replaced in this manner.

Attachment 1: P1070570.JPG
P1070570.JPG
Attachment 2: P1070568.JPG
P1070568.JPG
  4551   Thu Apr 21 14:39:43 2011 steveUpdateRF Systemnew strain relieved N connectors at AP

New right angle PVC, 2 x 2 x  1/4" installed at the AP table to strain relief the 1/4" spiral corrugated RF coaxes.

Attachment 1: P1070562.JPG
P1070562.JPG
Attachment 2: P1070564.JPG
P1070564.JPG
  4550   Thu Apr 21 08:26:42 2011 steveUpdatePEMPSL enclosure work today

The east side window guides  will be replaced by one long U-channel. There will be drilling into 2x2 steel frame. It should be done by 2pm today

This should remove the jerking motion of windows hitting the individual guides.

  4549   Wed Apr 20 23:20:49 2011 jamieSummaryComputersinstallation of CDS tools on pianosa

This is an overview of how I got (almost) all the CDS tools running on pianosa, the new Ubuntu 10.04 control room work station.

This is machine is experiment in minimizing the amount of custom configuration and source code compiling. I am attempting to install as many tools as possible from existing packages in

available packages

I was able to install a number of packages directly from the ubuntu archives, including fftw, grace, and ROOT:

apt-get install \
libfftw3-dev \
grace \
root-system

LSCSOFT

I installed all needed LSCSOFT packages (framecpp, libframe, metaio) from the well-maintained UWM LSCSOFT repository.

$ cat /etc/apt/sources.list.d/lscsoft.list
deb http://www.lsc-group.phys.uwm.edu/daswg/download/software/debian/ squeeze
deb-src http://www.lsc-group.phys.uwm.edu/daswg/download/software/debian/ squeeze contrib
sudo apt-get install lscsoft-archive-keyring
sudo apt-get update
sudo apt-get install ldas-tools-framecpp-dev libframe-dev libmetaio-dev lscsoft-user-en

You then need to source /opt/lscsoft/lscsoft-user-env.sh to use these packages.

EPICS

There actually appear to be a couple of projects that are trying to provide debs of EPICS. I was able to actually get epics working from one of them, but it didn't include some of the other needed packages (such as MEDM and BURT) so I fell back to using Keith's pre-build binary tarball.

Prereqs:

apt-get install \
libmotif-dev \
libxt-dev \
libxmu-dev \
libxprintutil-dev \
libxpm-dev \
libz-dev \
libxaw7-dev \
libpng-dev \
libgd2-xpm-dev \
libbz2-dev \
libssl-dev \
liblapack-dev \
gfortran

Pulled Keith's prebuild binary:

cd /ligo/apps
wget https://llocds.ligo-la.caltech.edu/daq/software/binary/apps/ubuntu/epics-3.14.10-ubuntu.tar.gz
tar zxf epics-3.14.10-ubuntu.tar.gz

GDS

I built GDS from svn, after I fixed some broken stuff [0]:

cd ~controls/src/gds
svn co https://redoubt.ligo-wa.caltech.edu/svn/gds/trunk
cd trunk
#fixed broken stuff [0]
source /opt/lscsoft/lscsoft-user-env.sh
./bootstrap
export GDSBUILD=online
export ROOTSYS=/usr
./configure --prefix=/ligo/apps/gds --enable-only-dtt --with-epics=/ligo/apps/epics-3.14.10
make
make install

dataviewer

I installed dataviewer from source:

cd ~controls/src/advLigoRTS
svn co https://redoubt.ligo-wa.caltech.edu/svn/advLigoRTS/trunk
cd trunk/src/dv
#fix stupid makefile /opt/rtapps --> /ligo/apps
make
make install

I found that the actual dataviewer wrapper script was also broken, so I made a new one:

$ cat /ligo/apps/dv/dataviewer
#!/bin/bash
export DVPATH=/ligo/apps/dv
ID=$$
DCDIR=/tmp/${ID}DC
mkdir $DCDIR
trap "rm -rf $DCDIR" EXIT
$DVPATH/dc3 -s ${NDSSERVER} -a $ID -b $DVPATH "$@"

environment

Finally, I made a environment definer file:

$ cat /ligo/apps/cds-user-env.sh
# source the lscsoft environment
. /opt/lscsoft/lscsoft-user-env.sh

# source the gds environment
. /ligo/apps/gds/etc/gds-user-env.sh

# special local epics setup
EPICS=/ligo/apps/epics
export LD_LIBRARY_PATH=${EPICS}/base/lib/linux-x86_64:$LD_LIBRARY_PATH
export LD_LIBRARY_PATH=${EPICS}/extensions/lib/linux-x86_64:$LD_LIBRARY_PATH
export LD_LIBRARY_PATH=${EPICS}/modules/seq/lib/linux-x86_64:$LD_LIBRARY_PATH
export PATH=${EPICS}/base/bin/linux-x86_64:$PATH
export PATH=${EPICS}/extensions/bin/linux-x86_64:$PATH
export PATH=${EPICS}/modules/seq/bin/linux-x86_64:$PATH

# dataviewer path
export PATH=/ligo/apps/dv:${PATH}

# specify the NDS server
export NDSSERVER=fb

[0] GDS was not compiling, because of what looked like bugs. I'm not sure why I'm the first person to catch these things. Stricter compiler?

To fix the following compile error:

TLGExport.cc:1337: error: ‘atoi’ was not declared in this scope

I made the following patch:

Index: /home/controls/src/gds/trunk/GUI/dttview/TLGExport.cc
===================================================================
--- /home/controls/src/gds/trunk/GUI/dttview/TLGExport.cc (revision 6423)
+++ /home/controls/src/gds/trunk/GUI/dttview/TLGExport.cc (working copy)
@@ -31,6 +31,7 @@
#include <iomanip>

#include <string.h>

#include <strings.h>

+#include <stdlib.h>


namespace ligogui {
using namespace std;

To fix the following compile error:

TLGPrint.cc:264: error: call of overloaded ‘abs(Int_t&)’ is ambiguous

I made the following patch:

Index: /home/controls/src/gds/trunk/GUI/dttview/TLGPrint.cc
===================================================================
--- /home/controls/src/gds/trunk/GUI/dttview/TLGPrint.cc (revision 6423)
+++ /home/controls/src/gds/trunk/GUI/dttview/TLGPrint.cc (working copy)
@@ -22,6 +22,7 @@
#include <fstream>

#include <map>
#include <cmath>

+#include <cstdlib>


namespace ligogui {
using namespace std;

  4548   Wed Apr 20 22:29:07 2011 sureshUpdateRF SystemPlan for LSC rack

The suggested layout of the 1Y2 Rack is shown below.

To simplify the wiring, I have largely kept demod boards with the same same LO frequency close to each other. 

The Heliax cables land on the top and bottom of the of subracks.  These are currently flexible plastic sheets.  Steve has agreed to replace them with something more rigid.  It would be good to have eight N-type connectors on the top and eight  at the bottom.  As  demod boards occur in sets of eight per subrack.  So it would be convenient if the 11 and 55 Mhz Heliax cables land on the top and the rest at the bottom.  In the layout I have shown the current situation. 

The LO signals to the boards come from the RF Distribution box and this is kept in the middle so that cables to both the subracks can be kept short.

The outputs of the AA filter boards from both subracks  have to be connected to the SCSI Interface board with a twisted pair ribbon cable. 

1Y2_Rack_Layout.png

  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

rogue_cable_1.png

Attachment 1: rogue_cable_1.png
rogue_cable_1.png
  4546   Wed Apr 20 20:42:55 2011 kiwamuUpdateVIDEOtoday's video session

[Steve / Suresh / Kiwamu]

90 % of unused video cables have been removed.

Still a couple of video cables are floating around the video MUX. They will be removed in the next week's session.

DSC_2931_ss.jpg

DSC_2938_ss.jpg

 

  4545   Wed Apr 20 11:02:18 2011 josephbUpdateCDSMEDM screens and Front Ends updated to new Matrices
We simply didn't any matrices larger than 16x16. If we had, than that matrix would not have worked properly since the beginning.

Quote:

Just a curiosity:

I just wonder how you have distingushed the difference between _111 and _111.

They are equivalent alone themselves. Have you looked at the contexts of the lines?
Or you just did not have the larger matrix than 16x16, did you?

 

  4544   Tue Apr 19 17:34:02 2011 KojiUpdateCDSMEDM screens and Front Ends updated to new Matrices

Just a curiosity:

I just wonder how you have distingushed the difference between _111 and _111.

They are equivalent alone themselves. Have you looked at the contexts of the lines?
Or you just did not have the larger matrix than 16x16, did you?

  4543   Tue Apr 19 15:48:43 2011 josephbUpdateCDSMEDM screens and Front Ends updated to new Matrices

Problem:

The original matrix naming conventions for the front ends was broken.  It used _11, _12,...,_1e, _1f, _110, _111 and so forth.  The code was changes to use _1_1, _1_2,...,_1_16,_1_17, and so on.

In addition the matrix of filter banks was modified to use the same naming convetion (instead of starting at zero, it now start with one).

Work Done:

I rebuilt all the models, and restarted them all.

I wrote a simple script to modify the burt restore files to have the correct names for all the stored matrix values.

I also modified all the suspension screens, by modifying the default screens in /opt/rtcds/caltech/c1/medm/master/

The C1SUS, C1SCX, C1SPX, C1SCY, C1SPY, and C1MCS models had their foton filter files modified to put filters into the newly changed named filters

  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.
  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].

Hardware:

  • 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

  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).

LSCrack.png

 

(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

  4539   Mon Apr 18 14:11:44 2011 kiwamuUpdateLSCRF status

 We will make them all green !!

 RF_Work_Status.png

Again, all the files are available in the svn.

https://nodus.ligo.caltech.edu:30889/svn/trunk/suresh/40m_RF_upgrade/

  4538   Mon Apr 18 13:05:57 2011 kiwamuSummaryLSCdemod board modification

Here is the idea how we upgrade the demodulation boards.

Basically we go ahead with two steps as depicted in the cartoon diagram below.

Once we finish the first step of upgrade, the board will be ready to install although the circuit won't be awesome in terms of noise performance.

 

demod_board.png

 

* * * (details) * * *

 First of all we will replace the home-made 90 degree splitter (see this entry) by a commercial splitter, PSCQ-2-51-W+ from Mini circuit. This is the step 1 basically.

At this point the boards will be ready to use in principle. I asked Steve to get three 90 degree splitters so that we can have at least three demodulators for the dual-recycled Michelson locking.

If they work very fine we will buy some more 90 degree splitters for full locking.

While we try to lock the dual-recycled Michelson once we will get a Cougar amplifier, remove all ERA-5s and install it such that we don't have to gain up and down in the circuit. This is the last step.

  4537   Sat Apr 16 02:00:14 2011 ranaUpdateLSC11MHz demod board : 90 degree splitter

One way to avoid some of the bad stuff in there is to take the 1 dBm input and amplify it to ~21 dBm before splitting and sending in to the Level 17 mixers.

One way to do this is by using the A3CP6025 from Teledyne-Cougar. Its an SMA connectorized amp which can put out 25 dBm and has a gain of 24 dB. We can just glue it onto the demod boards. Then we can remove the ERA-5 amplifiers and just use the broadband splitter as Kiwamu mentioned.

  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

Quote:

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

 

 

 

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