PSL preparation work report

Aug 6th 10am-5pm: (Steve, Jenne, Alberto, Kiwamu, Koji)

- We labeled the cables to be disconnected

• These will be disconnected in order to isolate the PSL table and the frame (housing) from the other part of the lab.
• Upon the labeling we made the list and the map of the cables to be removed.
• On Monday we disconnect those cables one by one accoding to the list.

- The following stuffs have been removed from the PSL table

• The big nuts at the side of the PSL table
• The cable ties on the PSL frame
• Innolight 2W
• The green pickoff optics at the edge
• The optics on the shelf
• The oscilloscopes on the shelf

- The OMC power supply cable was visited.

• The connections to the power supply were removed. There are two HV outputs.

- We put thick and long optical poles

• They are placed at the edge of the table so that we can put the plastic sheets on the table without touching the optics.

Plan on Monday

Aug 9th  9am-5pm: (Steve, Jenne, Alberto, Koji)

• Disconnecting the cables ==> All
• Shutting down the PSL ==> Steve/Koji
  • Draining the cooling water  ==> Steve
• Removals
  • The accelerometers ==> Jenne
  • The reference cavity chamber ==> Steve
  • The small periscope ==> Alberto
• Sealing of the table with the plastic sheets

• The chiller is planned to go to MIT 

Nancy notified me that the elog crashed. It was fixed.

I restarted elog, but it kept crashing. Some of the entries on Aug 6th caused the trouble.

I tried to refresh the pictures in entries 3376, 3377, 3378. Still it kept crashing.
I started to dig into the elog file itself. (/cvs/cds/caltech/elog/elog-2.7.5/logbooks/40m/100806a.log)

FInally I found that there was some invalid reply links in the entry 3379.

Date: Fri, 06 Aug 2010 19:29:59 -0700
Reply to: 3379
In reply to: 3379

The entry is refering this entry itself. That is weird. So I deleted the reply-to and in-reply-to lines.
Then elogd got happy.

In fact, 3379 was a dupulication of 3380, so I deleted this entry.

Jenne asked us to keep th MC locked and let the seismometers happy through this weekend.
Note that the work at the control room and the desks are no problem as far as you are quiet.

Nancy told Jenne and me that she finished the work and reverted the WFS to the old state at 4:30AM.
She could not make the elog as it has been crashed.

MC and old MC WFS looks working as usual.

From 6:40AM to 9:40AM the oscillation of the PMC looks present.

At 10:30AM I reduced the gain of the PMC from +15dB to +13dB.

I made some changes to the elog on nodus:

• Made a backup of /cvs/cds/caltech/elog/elog-2.7.5/elogd.cfg called elogd.cfg.bk.20100407 in the same directory
• Added a folder: /cvs/cds/caltech/elog/elog-2.7.5/logbooks/EAGER_Lab
• Restarted the elog daemon via the start-elog-nodus script in the elog-2.7.5 directory

I saw that the current version of the elog seems to be in the svn, so tried to svn the changes from nodus via ssh, but got this message:

"svn: This client is too old to work with working copy '/cvs/cds/caltech/elog/elog-2.7.5'; please get a newer Subversion client."

I feel I should svn this but don't want to *&#@ the svn/elog up.

For now I will leave it alone and ask a question: Is the folder /cvs/cds/caltech/elog/elog-2.7.5/ under SVN control? Is it also under CVS control?

TL;DR:  New tab added to elog.

The green xterm on op540m which is running the seisBLRMS DMF got stuck somehow ~3 days ago and lost its NDS connection. I closed the matlab session and restarted it. Seismic trends are now back online.

From how much to how much have you chnged the gain?

I changed the gains from all 4 0.01 to o.27, 0.23, 0.32 and 0.11 and the main alignment gain to be 0.8

I like to put the credit to Aidan for teaching Nancy how to use FOTON.

 Yes, I am sorry for not mentioning this.

Thanks Aidan

 E-log entry for Friday - will attach more plots to this entry on wednesday after i am back   to the 40.

Status	MC_Trans	MC_REF
New Control ON
New Control OFF
Old Control ON

The WFS and QPD servos were working. That was great.
Everything was fine except for the time series plots.

I could not get what story you are telling with the time series.
(e.g. your's are good or bad or anything)

 Well, the data is kind of not enough to be analysed in time domain,

But by far from what I analyse, I think that the new control is not worse than the old one.

I donot also find any better results, except for this one being theoritically stronger.

 Elog was down. Restarted with the script.

Work on Aug 9th

Steve, Jenne, Koji, Alberto, Aidan, Jan, Sharmila, Katherine

From 9am to 6pm

• Shutting down the PSL after the 90885 hours of service
• Removals
  • The accelerometers
    
  • The reference cavity chamber
    
  • The periscopes were left so far
• The cables between the PSL table and the outside have been disconnected
  • Listed items on Friday
  • Some unlisted items recorded and disconnected
  • Drained the cooling water from the chiller lines
  • Pulled out the chiller connections at the control room as well as the chiller control cables (temp sens & RS232C)
• Sealed the PSL table with plastic sheets
  • Put antistatic films to the table (they are supported by the long optical poles)
  • Used capton tapes to fix the films on to the table
  • Put the white huge plastic sheet to cover the table at once
  • Some spaces at the edge of the tables are left flat such that the C-clamps can be attached
• Sealed the AP and the ITMY tables by capton tapes

Some photos are attached in this entry. All of the photos found in the picasa album (click the slideshow)

[Jenna & Alastair]

We changed the locking time constant on one of the Rubidium clocks using the RbMon software that came with it. We had to use the ancient Dell laptop latitudeD810 because it has a serial port built in, and we couldn't get the usb->serial adapter to work right with the clock. We tried the usb connector on more than one computer, and we had installed the right adapter and the computer seemed to recognize it fine, it just wouldn't communicate with the clock. We even tried it with the Dell latitute laptop and it still failed to work, so the only way seems to be to use the serial port directly.

The clock has a default time constant of 18.2 hours because it's designed to be locked to a GPS clock which is less stable than the Rb clock itself, so we changed it to a time constant of .57 hours. We also changed the length of the BNC cables to get the DC offset to 10mV, but then as I was typing this, we opened up data viewer to look at the real time data and saw the output suddenly leap up, and found that the offset is now -5mV mysteriously, so we went to investigate and found that the gain of the SR560 was still set to 1 from a calibration. We beat one of the clocks with a marconi for a few minutes with the gain still at this level to do another calibration, and then hooked the clocks back up together and upped the gain to 100. The DC offset is currently about 2.5mV. We're going to leave them alone for a few hours, and then check to see what the signal looks like over that period.

 Alastair and I restarted the c1iovme around the time of my last elog entry (~3:20).

Mike Gerfen, Koji and Steve,

Our old ( 6 x 10 x 1 ) ft Newport optical table will have the same height as the neighboring AP table when this job is finished.

Today's work was to elevate the optical table ~ 2400 lbs to 30" clearance to create a workable space below.

Atm1,  enclosure frame was raised by 6"

Atm2,  2 pellet jacks and 4x4 technology in the work.

Atm3,  ready for drill and tap with jig plate in place, note 4 Al legs 8" OD. 1/4" wall safely supporting the load

Atm4,  showing clamps that holding 1/2" plywood with jigs

Atm5, We removed the 4 old legs: 6" OD steel, 1/4" wall and 10" high after they were unloaded.

Result of the accelerometer measurement

Introduction

We wanted to characterize the PSL table before the work before its lifting up.
We put a set of three-axis Wilcoxon accelerometers on the ground and another set on the PSL table through the weekend.

Result

- The data at 9th Aug 00:00(UTC) is used. This was Sunday 5PM in the local time.
- The freq resolution was 0.01Hz. The # of avg was 50.

- The accelerometer signals were calibrated by the value 1.2e-7 V/(m/s^2). We use this absolute value of the spectrum for the comparison purpose.

- The accelerometers were aligned to North(X), East(Y), and Up(Z). There was the coherence observed from 2~20Hz.
  The transfer functions are valid only this frequency region although we still can set the lower bound of them.

- The transfer functions in the horizontal directions show huge peaks at around 20Hz. The Q of the peaks are ~30 to ~100.
  The vertical transfer function shows somewhat lower peak at around 50Hz with Q of ~10.

Some thoughts

- The low resonant freq and the high Q of the horizontal mode comes from the heaviness of the table.

- We are going to raise the table. This will usually mean that we get the lower resonant freq. This is not nice.

- So, the decision to use 6 tripods rather than 4 was right.
- The steel tripods are expected to give both more rigidity and more damping than the chep-looking hollow Newport legs.
- Concrete grouting of the tripods will also lower the effective height and will benefit for us.

You'll never guess what happened: the elog crashed!

I restarted it with the script. Yay.

Summary of this Week's Activities:

Thursday, August 5:

X-Displacement Transfer Function Measurement

JPL Tour

Friday, August 6:

Y-Displacement Transfer Function Measurement

Z-Displacement Transfer Function Measurement

Monday, August 9:

Worked on COMSOL/MatLab Interface --> problems may be due to older version

Discussed with Koji options for calling our COMSOL sales representative

Jan and I decided that there is in fact something wrong with the installations on both my Mac and Kallo

Reinstalled on both machines, but the problem was not solved

Jan said we'd go see Larry tomorrow

Tuesday, August 10:

Attempted to figure out Time-Dependent Modal Analysis --> don't think it's what we need

Began reading the LiveLink for MatLab documentation --> even the directions in this produced issues

Discovered "Prescribed acceleration" option for gravity:

A test with it on the simplest stack eliminated the unwanted oscillation, which I guess is a partial success...

Trying the same thing with Koji on a simple pendulum, however, didn't produce the expected increase in resonant frequency

(Jan was unable to see Larry today, but we're meeting on Wednesday instead).

Wednesday, August 11 (morning):

Some background research on multiple-layer stack theory

Began working on presentations

I took some measurements of the clock this morning, first without the box, then with the box, then without the box again. All the noise levels look pretty much the same. When I first put the box on, it was only propped up on one side, so I think the clocks got a bit overheated and the data looks ridiculous, which is the first plot. I took it off and let them cool down a bit, and then put the box on, this time with a generous 3 inch gap at the bottom all the way around, and it seemed to be fine after that.

The calibration for the data is pi (rad) /6415 (counts) /100.

Aidan: I edited this post to change the plots from Postscripts to PDFs.

While working on a test stand at LLO, I've discovered that there's a new update to the Real Time Code Generator that breaks virtually all of our current models.

Previously, we've been using the cdsIPCx part as a flexible link between models, and could be set to RFM (reflected memory), SHMEM (shared memory on the local computer), or PCIE (pci express or dolphin I think) depending on what was written in the IPC file (found in /cvs/cds/caltech/chans/ipc/C1.ipc).

Recently, three new parts were added called cdsIPCx_SHMEM, cdsIPCx_RFM, cdsIPCx_PCIE, and the previous cdsIPCx broken.  The cdsIPCx_***** has to match the type written in the IPC file or else it errors out with a rather unhelpful error message which doesn't tell you which part/line is in conflict...

i.e.

***ERROR: IPCx type mis-match: I vs. ISHM
make: *** [g1lsc] Error 255

In anycase, when using a current checkout (updated or checked out after ~July 30th), all cdsIPCx blocks in the simulink models needs to be changed to the approriate type.  I'm trying to get a new CDS_PARTS.mdl file I updated into the svn, but for now you can just open up the model file directly in the /advLigoRTS/src/epics/simLink/lib directory and copy it in from there (i.e. cdsIPCx_SHMEM.mdl) to your model file.  I'm also trying to get the feCodeGen.pl file changed so the error message actually tells you what channel/part is mismatching so you don't have to guess.

An easy way to modify a file for all shared memory connections without doing a ton of cutting, pasting and renaming is:

sed -i 's/"cdsIPCx"/"cdsIPCx_SHMEM"/g' file_name_here.mdl

We unsynched the clocks by unhooking the 1pps locking. I've added it to the plot of the other measurements here, and we've divided by a factor of sqrt(2) in the calibration to get the phase noise from just one clock, so the calibration is now

pi (rad) /6415 (counts) /100/sqrt(2).

I've also added the noise of the clock according to SRS to the plot.

The units of this plot are rad/rt(Hz). I've no idea why it just says magnitude.

The elog crashed, so we restarted it again.

 This is a known thing (at least to me and Rana), so it's not just you.  When you put in some points like your PD Spec, the units disappear, and I've never figured out how to get them back while keeping the points.  Thanks for putting the units in your entry though.  If anyone else does know how to get the units to 'stick' where they're supposed to be, that would be helpful. 

Katharine, Sharmila, Gopal, Kiwamu, Jenne, Aidan, Steve, and Koji

A guy from the carpenter shop has done the drilling work in the morning.

In the afternoon we wrapped the central part of the interferometer with plastic sheets in order to avoid the dusts from the tile ripping that will happen tomorrow.

I powered down 1Y1 and 1Y2 instrument racks of MC and RF-systems this morning.

Both racks, SP table, clean tools-parts boxes and MC2 area are also covered with plastics.

Bertin Bros. Construction, Inc is working on the floor preparation. Their head man is Robby Bertin, cell 626. 831.2264

Today's job:

remove tiles, clean off tile glue, drill for ribbed  steel bars, rough clean- surface for good bounding. paint floor with bounding agent

Current status of the new CDS test (summaries can be found on the wiki)

- Cables 

  All the necessary cables are in our hands, such as SCSIs, 37 pin D-sub and 3 pin power cables.

  With a big help from Jenne and Koji, we made 37 pin F/M cables and 3 pin power cables on the last Tuesday.

  Now all the cables are connected to the machines except for the 3 pin power cables.

  To install the power cables I will switch off Sorensens at new 1X5  for a minute.

- Suspension model file 

  The model file named C1SUS was made and I succeeded in compiling and building it. So it is ready for the test.

  But some medm screens look like not correctly complied.

  For example the channel names which are listed on C1SUS_MONITOR_ADC0.adl aren't correctly assigned.

- ADCs 

 All the ADC channels are working. Also the channel assignments are correct.

 I checked all the ADC channels if it was working while I ran the front end realtime code C1SUS.

 By injecting a signal from a function generator directly to the SCSIs, I could clearly see the numbers hopping on medm screens.

- DACs 

  None of them are working although the computer can recognize that all three DAC cards are mounted.

  I think something in the IOP file and the model file may be wrong because this symptom looks similar to that of C1ISCEX we tested two weeks before ( see this entry ) 

  I have to fix it anyhow because the DACs are very necessary part for this damping test.

- Binary Outputs

  They didn't work at all. Even the computer didn't recognize the binary output cards.

  I think I should put some magical components on the model files.

- Conversion of the filter coefficients 

  The conversion of the filter coefficients has been doen yesterday.

  It looks running well because I can load and unload these filters on medm screens.

  I manually copied the filter coefficients from the current suspension filter file to that of new filter file.

 The current file can be found under /cvs/cds/caltech/chans/,  and the new one is under /cvs/cds/rtcds/caltech/c1/chans

Suspended works

   - Binary Outputs

   - simlink realtime model with the new CDS PARTS ( see the notice from Joe )

 

To be done

   - let DACs work

   - damping tests

with script

(sad story)

When I was working on a new front end machine c1sus, I found that make command didn't run and gave the following message.

      "make:warning:clock skew detected.Your build may be incomplete"

This was caused by a clock difference between the nfs (nodus) and the terminal machine (c1sus).

I had to set up ntp daemon to synchronize them. Here is a procedure to set up it

(how to)

- log in to a front end machine

              ssh c1sus

- enable the ntp daemon

              sudo ntsysv

- configure the ntpd

              vi (emacs)  /etc/ntp.conf

- below is the contents I wrote on ntp.conf

             server 192.168.113.200  minpoll 4 maxpoll 4 iburst

      driftfile /var/lib/ntp/drift

First, awesome progress.

Second, the Binary Output parts do in fact need to be added to the c1sus model.  They don't need to appear in the IOP though.  (They are somehow automatically taken care of by the IOP code). 

It looks like in the 2004 revision in SVN, the cdsCDO32 part (located in the CDS_PARTS.mdl/IO_PARTS) was broken.  I fixed it and updated the svn with it, so a svn update should pull the corrected version.

I'm not sure whats wrong with the DAQs.  I'll try to take a closer look at the model file tonight and see if I can make suggestions.  When you write outputs on DAC_0 or DAC_1 is the C1SUS GDS TP screen showing anything?

I took a look at the data from the middle of the night to see if it was significantly quieter than the data from the day, but it doesn't seem to be. The plot shows data from yesterday around 12:30pm and from this morning around 2am. It's a bit quieter at low frequencies, but not by much.

Tiles and adhesive removed. There were no dust storms created. Solvent paint- removal made the hole IFO -lab smell like the paint shop.

The south door is open with a fan blowing air inside. The north-west door is open through control room to outside to let air rinse the drying

paint-removal. Koji is  taking lunch break while test riding our new PSL table legs.

I made some measurement of the SCR (signal to contrast ratio) from the signal from the EOM and the AOM.

The recipe for that was:

1. Trigger the camera at 20 Hz (from function generator).

2. Take a series of 20 images.

3. Do FFT to take out the DC component.

4. Extract the beat signal out of the FFT'd data.

5. Block the EOM.

6. Take another set of images of the AOM beam.

7. Take more(!) images, but this time of the background (blocking both EOM and AOM).

So the SCR is calculated by the ratio of the FFT'd DC and the 5 Hz signal. Using the CCD, I obtained the SCR to be 0.075 ± 0.01. Previously, we expected our SCR to be 0.09 as in the previous e-log entry.

The plot for that is:

 After measuring the SCR, I also measured the amplitude of the sideband and made an amplitude profile of the 40 MHz sideband.

The amplitude measurement is done as follows:

We know that the our 5 Hz signal consists of,

Sig = A_r * A_sb    where A_r = amplitude of the reference beam, A_sb= amplitude of the sideband

So, A_sb = Sig / A_r .

But,  A_r = sqrt ( P_AOM - Background),

Thus  A_sb = Sig / sqrt( P_AOM - Background) .

So the amplitude profile is done by taking the 5 Hz beat signal and dividing by the square root of the AOM beam minus the background light.

The plots looks like this:

The solo sideband profile looks like this:

Next we plan to trigger the camera with a 1 KHz signal and take snaps at n* T/4 (where n=0,1,2,3) of the period of the beat signal. So the plan is to trigger the camera at the point where the red dots appear in following cartoon.

Some more details of this setup will be posted later.

This sounds very relieving although this could be a lower bound of the number.
Why didn't you use the output on the PD which just give us the direct observation of your so-called SCR.

Ed: I meant time series of the PD output

 The SCR was at first measured using the output of the PD. That was exactly from where we got our 0.09 (previous elog entry). The second measurement was from the CCD.

Yes.  

The medm screen C1SUS_GDS_TP.adl showed some numbers which correspond to that I wrote  on the outputs.

But I still could not get any physical voltage coming from the DACs.

 script

 More of the same. 

Who is putting weird figures into the elog?!?!  I haven't checked lately, but this is what usually crashes the elog.  It's been happening a lot lately, and it might be the .pdf's. 

Let's play a new game.  We'll call this game "Everyone only use .png files for the next week" Ready? GO!

Since the laser is off, Jenne and I rasied the chiller-chiller (small AC in the Control Room) set point temperature to 73 degree F (from 68F) to save people from shivering.

Time Domain Analysis on a Driven, Damped Simple Pendulum has produced a method for implementing gravity.

COMSOL made this simple task a cryptic one: the following methods had previously failed:

• Previous Frequency Domain testing lead to unwanted oscillations of all loads.
• Prescribed accelerations at first seemed to create a constant gravity, but instead incorrectly constrained net acceleration to the inputted amount

Methodology:

1) An (approximately) impulse displacement was applied in the horizontal direction. The pendulum bob's displacement was observed for varying pendulum lengths.

2) The drive and response displacements vs. time were FFT'd to produce transfer functions.

3) The fundamental frequencies were inverted, squared, and plotted against frequency.

4) Since the graph is linear with an R^2 of over 0.99, it is reasonable to assume that gravity is properly acting as a restoration force.

 I have taken the charger for the dark gray dell laptop from its station, and have labelled the information there too.

Will keep it back tonight.

Do we know what causes the crashes for definite? Let's give the whole knowledge gathering a shot. Surfs welcome to post. Please follow the format and keep it brief. P.S. if the elog stops responding or hangs while you're trying to edit a post or write a post, you may have crashed it.

Person

• Crashes

Dmass

• I have crashed the elog with downsized jpegs (~300-900kB).
• I see jpegs on the front page of the 40m (which seem to have not crashed it?)
• I have posted pdf's with and without png thumbnails (associated automatically via the Mac program preview) without problem.

Edit this post to add your own experience using the above format

Koji, Rana and Steve

The floor preparation continued today. The really messy part of drilling and jack-hammering the concrete were done in controlled manner.

Particle counts peaked at 106K of 0.3 micron and 13 K of 1.0 micron particles/ cfmin at the top of SP table.

Legs were installed with the help of Koji and strongman Rana. Professor Rana was very useful lifting the 85 lbs legs. 

Atm1, Drilling holes for ribbed bar reinforcement of concrete

Atm2, Koji and Rana are playing hide and seek while installing legs

Atm3-4, 6 Rigid tripod legs attached by 6x3 of 1/4-20x 7/8 screws. The top plates of the legs were torqued to 108 ft/lbs by Rana

 Here's an overview of the rubidium measurement:

 We have two SRS FS275 Rubidium clocks which are locked together using the built-in PLL through the 1pps input/output. The default time constant for this locking is 18.2 hours because it's designed to be locked to a GPS. We changed this time constant to .57 hours (as decribed in this elog entry) to get the clocks to more reliably lock to each other. We then mix the 10MHz outputs together using a 7dbm mixer (see elog here and picture below)

The signal then goes through an AC-coupled SR560 with a gain of 100 and LPF at 10kHz, and is then fed into the DAQ. In the first picture below you can make out what all the lights are labeled, and in the second you can see what lights are on. I couldn't get a picture that did both in one, sadly.

 One day I'll get to be part of the krew

[Jenne, Yoichi]

We characterized Tip Tilts numbers 2 & 3 today.  Recall #4 is the one which Koji and I measured some time ago, and #s 1 & 5 have yet to be suspended (that's on the to-do list for tomorrow).

When we began looking at #3 (the one which had been in the BS chamber for a few days, but was removed for characterization) we found that the pitch pointing was way off.  The beam was way too low after reflection.  So we adjusted that (and got it right on the first try....a miracle!).  This does however make me pretty concerned about our in-chamber pointing.  Are we destroying our pointing during travel between the cleanroom and the chambers?  Is there anything we can do about it? Pointing doesn't seem to be lost when we move them around on the tables in the cleanroom, ie we can pick up a TT, move it, leave it for a while, move it back to the oplev, and the pointing still seems okay.  But the TT which was sent to the chambers came back with bad pointing. I'm sure this is related to the hysteresis we see in the pointing if we poke the top of the mirror holder versus the bottom when exciting pitch motion.

For both #2 and #3, we measured the frequency and Q of Pitch, Yaw, Pos, Side, Vert motion.  For the Vert motion, we measured both without and with EQ stops as dampers.  For the other modes, all were measured with the ECD backplane in place.  Pitch and Yaw were measured with reflection off of the mirror surface onto the PD, while Pos, Side and Vert were measured using the wire clamp on the mirror holder to obscure the beam as a shadow sensor.

TT #2

Pitch: Overdamped, no freq measured, Q < 1/2

Yaw: freq ~1.8Hz, Q between 2-7

Pos: freq ~1.75Hz, Q too low to measure, but above critically damped

Side: freq ~ 1.8Hz, Q~5

Vert no dampers: freq ~20Hz, Q~36

Vert with dampers on outer screws: freq~24Hz, Q~8,

TT #3

Pitch: no freq measured.  Q~1/2?  Upon being excited in Pitch, the beam started down way below the photodiode, came up a little past its DC place, and went back down a tiny bit.  So not quite overdamped.

Yaw: freq ~1.96Hz, Q very low

Pos: freq ~1.72Hz, Q~3

Side: freq ~1.85Hz, Q~6

Vert no dampers: freq ~20Hz, Q~75

Vert with dampers on outer screws: freq ~20Hz, Q~34  (Frequency stayed constant....we did several measurements both with and without the dampers...but the half life time changed significantly)

Things we noticed:  Koji and I had been concerned the last time we were looking at TT#2 because the frequency got lower and the Q seemed to get higher when we added the damping to the vertical blades.  Yoichi and I did not find that to be true today.  We did notice, however, that the EQ stop screws with the viton had been placed in the holes closer to the clamping point, whereas with TT #4 the screws had been placed in the holes farther from the clamping point.  We moved the screws on TT #2 to the outer holes, and noticed that the frequency increased slightly, and the Q significantly decreased.  We then followed this outer-hole philosophy when installing screws in TT #3.

To Do List: We need to suspend the ECDs and the Optics for the remaining two Tip Tilts, and to characterize them.  We also (probably farther-future) need to take transfer functions using a shaker / shake table with our spare Tip Tilt.  After all the TTs are suspended and have their modes measured, we will be ready for installation into the chamber during the next vent.

 Zach

• I get so many freebies it's ridiculous

The inner and outer screw holes of the EQ stop Jenne is talking about are shown in the photo below.

 Since we had a similar trouble with the DAC at CLIO, I checked if this problem comes from the same origin.

The origin of the problem we had was that although the board was sold as 16 channel DAC, the firmware was set to use only 8ch.

To see if this problem exist in the DAC boards of c1sus, I added the following code to the /cvs/cds/caltech/cds/advLigoRTS/src/fe/map.c

printk("DAC ASSC = 0x%x\n",dacPtr[devNum]->ASSC);

in the definition of mapDac() function.

This code prints the information of the ASSC (Assembly Configuration) register of the PMC66-16AO16 board as a kernel message at the start up time of the realtime code. You can check the message with dmesg command.

After the modification, I recompiled the c1sus and installed it.

make c1sus; make install-c1sus

After starting c1sus, I checked the dmesg. Then found that the ASSC register was set to 0x130006. To decipher this magic number, you have to consult with the manual of the DAC, which is available online.

http://www.generalstandards.com/view-products.php?product=pmc66-16ao16

The manual says the 17th and 18th bits of this number set the number of channels. Those bits are 11 for 0x130006. According to the manual, 11 means 16 channels are present. So it seems that the ASSC register is correctly set. In the case of CLIO, the ASSC register was 0x110003, meaning only 8 channels are present.

Unfortunately, the ASSC register was not the cause of the problem, but at least this possibility was checked.

I just restarted the elog after I found it down a few minutes ago.

Tuesday, 17 August : fill tunnel, set table height, level table and balance load

Wednesday : grout tripod legs and leave it alone

Thursday : built  guide-form for concrete

Friday :  pour concrete

Monday, 23 August : remove guide forms and clean up