The PID loop is ready to be run on the green beat note but, since the tanks are open, there is no green transmission from the end getting to the PSL table. Nevertheless, here's the screen for the PID loop. The loop script is still in my directory /cvs/cds/caltech/users/abrooks/GRNXSlowServo

The medm screen is attached. It shows the current beat note frequency in MHz ()

In c1auxey/ETMYaux.db I added a couple of channels. These are all displayed on the MEDM screen. I added them to autoBurt.req as well.

• C1:LSC-EX_GRNLSR_TEMP_NOM: the zero-volt setpoint temperature of the end laser (as set on the front panel of the Mephisto controller). This must be entered manually in EPICS as there is no way to read it remotely. [Sad Face]
• C1:LSC-EX_GRNLSR_TEMP_CALC: the sum of the zero-volt set point temperature and the offset temperature set by the input voltage from C1:LSC-EX_GREENLASER_TEMP

I rebooted c1auxey to get these to work.

Once we get the green beat back again, the PID loop should servo on the end laser temperature to drive the Beat Frequency to the Frequency Setpoint, C1:LSC-EX_GRN_PID_SETPT, which can be set by the pink slider.

RA: All MEDM screens must be in the proper MEDM directory!! Also, all perl scripts must have a .pl extension!!! Also, all scripts must be in the scripts directory even if they are in development!!! And all scripts should use 'env' rather than have absolute pathnames for the location of perl, csh, tcsh, python, etc.

 I measured the SRM OSEM (no magnets at the moment) noise out of the satellite box with a SRS785 spectrum analyzer. I inserted a break out board into the cable going from the satellite box to the whitening board. The transimpedances of the SRM OSEMs are still 29.2 kOhm. The DC voltages out of the SRM satellite box are about 1.7 V. The signal was AC coupled using SR560 with two poles at 0.03 Hz and a gain of 10.

The noise is consistent with the one measured by the ADC except for the 3 Hz peak which does not show up in the ADC spectrum from Sunday. The peak appears in several channels I looked at. The instrument noise floor was measured by terminating the SR560 with 50 Ohm.

I recommend to change all OSEM transimpedance gains from 29 to 161 kV/A. Beyond this gain one will rail the AA filter module when the magnet is fully out of the OSEM.

The OSEM noise at 1 Hz is about factor of 10 above the shot noise. The damping loops impress this noise on the optics around the pendulum resonance frequency. Also the total contribution to the MC cavity length is sqrt(12) time the single sensor as there are 12 OSEMs contributing to MC length. The ADC noise is currently close but never the less not limiting the OSEM noise below 100 Hz. It can be further reduced by getting an extra factor of 2-3 in whitening gain above ~0.3 Hz. The rms of the ADC input of the modified PRM SD (R64 = 161 kOhm) channel is 10-20 cts during the day with damping loop off and whitening on.

The transimpedance amplifier LT1125CS is also not supposed to be limiting the noise. At 1 Hz the 1/f part of the noise: In<1pA/rtHz and Vn<20nV/rtHz.

 That's not unreasonable. But if we try 

 grep "perl" /cvs/cds/rtcds/caltech/c1/scripts/*/* 

you can see that we've got a fair amount of housekeeping to attend to. We might want to think about tidying up the scripts directory as part of the cds upgrade.

import re
o = open("output.adl","w")
data = open("test.adl").read()
o.write( re.sub("C0:TIM-PACIFIC_STRING","C1:FEC-34_TIME_STRING",data)  )
o.close()

The next step is to figure out how to apply this to all the files in a directory.

[Jenne, Suresh]

The ETM assembly has moved forward a couple of steps.  We have completed the following:

1) Positioning the guide rod and wire stand-off on both the ETMs (5 and 7)

2) The magnets had to be cleaned with an acetone wash as they had touched the plastic Petri-dish (not cleaned for vacuum).

3) The magnets and the Al dumb-bells have been glued together and left to cure in the gluing fixture.

4) The guide-rod and wire stand-offs have also been glued to the optic and left to cure for 24 hrs.

JD:  As you can see in my nifty status table, we are nearing the end of the suspension story.  

We are going to try (but can't guarantee) to get ETMX to Bob for baking by Friday at lunchtime, that way we can re-suspend it on ~Monday, and place it in the chamber.  Then we could potentially begin Green arm locking next week.  Steve has (hopefully!!) ordered the spring plungers for ETMY.  The receiving and baking of the spring plungers is the only current delay that I can foresee, and that only is relevant for one of the optics. 

We (who is going to be in charge of this?) still need to move the SRM OSEMs & cables & connectors to the ITMY chamber from the BS chamber. 

(Kiwamu, Yuta)

Background:
  Yesterday, we aligned the Faraday and the beam reached SM2 at BS table.
  Today, we placed a new PRM tower to BS table.

What we did:
  1. Moved IPPO, IPPOSSM1, IPPOSSM3, IPANGSM1, IPANGSM2 out from the BS chamber.

  2. Moved SRM tower(at PRM's place) to the ITMX chamber.

  3. Placed the new PRM tower at the BS chamber.

  4. Adjusted positions of the OSEMs for PRM and BS so that the sensor output can have roughly half of their maximum.

  5. Checked damping servo for PRM and BS. They were working and helped us when adjusting OSEM positions.

  6. Placed IPPO back and using SM2, made the beam hit PR2 at ITMX table.

  7. Aligned the PRM so that the reflected beam path overlaps the incident beam.
     We checked it by looking at MMT1.
     For the alignment, we used IFO align sliders(C1:SUS-PRM_PIT_COMM, YAW_COMM).
        To use them, we rebooted c1susaux.

Result:
  1. The new PRM tower is placed.

  2. OSEM sensor outputs for PRM and BS are;

    We changed PRM aligning slider values, and they changed OSEM sensor outputs. We set the slider values to 0 when adjusting OSEM positions.

An improved python code to apply a replacement to all *.adl files in a directory would be:

import re, os
files = os.listdir("./")
  for file in files:
    if ".adl" in str(file):
      data = open(file).read()
      o = open(file,"w")
      o.write( re.sub("C0:TIM-PACIFIC_STRING","C1:FEC-34_TIME_STRING",data)  )
      o.close()

Of course, this entire python script can be replaced with a single sed command:

sed -i 's/C0:TIM-PACIFIC_STRING/C1:FEC-34_TIME_STRING/g' *

A more complicated script could be written which looks for key identifiers either in the file header or inside the file to determine which front end is appropriate, using a dictionary like:

dcuid_dict = {"BS":21,"PRM":37,"SRM":37,"ITMX":21,"ITMY":21,"MC1":36,"MC2":36,"MC3":36,"ETMX":24,"ETMY":26}

and then using for loops and if statements.

The following channels should be named as below to keep in line with their names pre-upgrade rather than use _DAQ in the name.

Problem:

Sometime in the last 3 weeks, probably when Alex brought his latest changes from Hanford to the 40m and did an SVN update, the code which generates the names of the filter .adl files links for the overall matrix view broke.

Fix:

I modified FE code gen to use $basename instead of the base name after the top name transform (this changes _ to - after the first 3 letters

@@ -3520,11 +3522,11 @@
 
                  my $tn = top_name_transform($basename);
                  my $basename1 = $usite . ":" . $tn . "_";
-                 my $filtername1 = $usite . $tn;
+                 my $filtername1 = $usite . $basename;

Still having problems:

The filter modules built with the matrix of filter modules run (offests/gains work), but will not load filter coefficients/filter names.  All the other filter modules outside the matrix seem to load fine.  At this point, doing a rebuild of any of the front end machines may cause the A2L filter banks to be unloadable.

(Joe, Suresh, Yuta)

Currently, only 2 ADC cards work on c1sus machine.
No QPD inputs(e.g. MC2 trans), and no RFM.

Summary:
  We wanted to have PEM(physical environment montor) channels, so we moved a ADC card in c1sus machine.
  It ended up with destroying one of the 3 ADCs.

What we did:
  1. Moved ADC card at PCIe expansion board slot 0 to other empty slot.
     What we call PCI slot 0 was "DO NOT USE" in LIGO-T10005230-v1, so we moved it.

  2. Connected that ADC card to PEM channel box at 1X7 via SCSI cable.

  3. ADC card order is changed, so we checked ADC number assinging and re-labeled the cable.

  4. Found RFM is not working(c1sus and c1ioo not talking) and fb is in a weird state(Status: 0x4000 in GDS screens)

  5. Swapped the cabling so that ADC card 0 will be connected to timing interface card at slot1, but didn't help.
     More than that, we suffered ADC timeout.

  6. Tried ADC card swapping, slot position changing, taking out some of the ADC cards, etc.
     We found that ADC timeout doesn't happen with 2 ADC cards.
     But if we connect one of the ADC card to the timing interface card at slot 8, c1sus ADC timeouts with 2 ADC cards, too.
     So, I think that timing interface card is bad.

  7. Stopped rebooting c1sus again and again. We decided to investigate the problem tomorrow.
     We only need ADC card 0 and 1 for MC damping.(see this wiki page)
       ADC card 0: all UL/UR/LR/LL SENs
       ADC card 1: all SD SENs     
       ADC card 2: all QPDs

Result:
  We can damp optics and lock MC.
  We can't do A2L because RFM is not working.
  We can't see MC2 trans because we currently don't have ADC card 2.

[Jenne, Suresh]

Today has been a downright miserable day in the world of suspension work. Thumbs down to that: 

Yesterday, we had glued 2 full sets of magnets to dumbbells.  Today, half of those broke.  I think I put too thin of a layer of glue on the magnets when gluing them to the dumbbells.  All magnet/dumbbell assemblies should pass the test of being picked up by the dumbbell while the magnet is stuck to the optical table or a razor blade.  6 of the 12 magnets failed this test. Suresh soaked the dumbbells that had been used in acetone, and scrubbed them, so we can reuse them when we reglue things tomorrow.  By some miracle, we have exactly one full set intact (for each set of 6, we need 4 of one direction and 2 of the other).  This was frustrating, but not yet a deal-breaker.  That part comes next....

I got ETMU05 nicely aligned in the magnet gluing fixture, and then was on my last check of whether the side magnets would be glued in the correct place when I realized that the fixture is all wrong for the ETMs.  This final check was added to the procedure after the drama with the ITMs of having the side magnets glued incorrectly as a result of the fixture being specific to the wedge angle of the optic.  Kiwamu and I had set the fixture to be just right for the ~1deg wedge corner station optics, but the ETMs have a 2.35deg wedge (according to the Coastline spec sheet, which is consistent with our measurements when placing the guiderod and standoffs).  Suresh and I need to reset the height of the optic in the fixture using more teflon sheets, but we don't have a whole lot of options ready in the cleanroom.  We're going to cut some more pieces and ask Bob to clean them tomorrow.  Since the way the fixture holds the teflon is a little hoaky, Suresh suggested just resting the optic on teflon pads, rather than screwing the teflon to the fixture, and then putting the optic on the pads.  We'll try Suresh's method tomorrow, and hopefully it will be pretty easy. 

At least the guiderods and standoffs were successfully glued to the optics....

Here's the updated Status Table.  I don't think we're going to be able to have an ETM ready for the chambers early next week, but we should still be able to have both ready for the Monday after Thanksgiving.  The spring plungers arrived today, and were given immediately to Bob and Daphen for cleaning.

(Kiwamu, Yuta)

Summary:
  Yesterday, we placed the new PRM to BS chamber and the beam reached PR2 at ITMX chamber.
  Today, we lead the PRM reflected beam back to AP table.
  Also, we aligned PRs so that the beam hits ITMX and ITMY.

What we did:
  1. Aligned PR2 at ITMX chamber and PR3 at BS chamber so that the beam hits ITMY.

  2. Aligned ITMX using IFO_ALIGN sliders so that the reflected beam overlaps at BS.

  3. Aligned BS using IFO_ALIGN sliders so that the splitted beam to ITMX overlaps the green beam from the X-end.

  4. Roughly aligned ITMY using IFO_ALIGN sliders so that the reflected green goes to far x-end.

  5. From yesterdays in-vac work, the reflected beam from PRM reached the Faraday.
     Aligned 2 steering mirrors in MC chamber so that the beam reaches AP table.

  6. Found the beam is double-spotted by a steering mirror at just after the Faraday symmetric port.
      The mirror is Y1-2037-45S. The beam is hitting it in ~10deg, so we have to replace it.

Plan:
  - replace the steering mirror right next to the Faraday symmetric port.
  - recyled Michealson

Note:
  We had to use "ITMX" channels to align ITMY. We have to fix and check X-Y confusion.
  Also, damping servo for ITMs does not seem to work. We have to check this.

I measured the optical and electrical transfer functions for REFL55 and calculated the RF transimpedance. To measure the optical transfer function, I used the light from an AM laser to simultaneously measure the transfer functions of REFL55 and a New Focus 1611 photodiode. I combined these two transfer functions to get the RF transimpedance for REFL55. I also measured the electrical transfer function by putting the RF signal from the network analyzer in the test input of the photodiode.

I put all of the plots on the wiki at http://lhocds.ligo-wa.caltech.edu:8000/40m/Electronics/REFL55.

Problem:

ADCs are timing out on c1sus when we have more than 3.

Talked with Rolf:

Alex will be back tomorrow (he took yesterday and today off), so I talked with Rolf.

He said ordering shouldn't make a difference and he's not sure why would be having a problem. However, when he loads the chassis, he tends to put all the ADCs on the same PCI bus (the back plane apparently contains multiples).  Slot 1 is its own bus, Slots 2-9 should be the same bus, and 10-17should be the same bus.

He also mentioned that when you use dmesg and see a line like "ADC TIMEOUT # ##### ######", the first number should be the ADC number, which is useful for determining which one is reporting back slow.

Plan:

Disconnect c1sus IO chassis completely, pull it out, pull out all cards, check connectors, and repopulate with Rolf's suggestions and keeping this elog in mind.

In regards to the RFM, it looks like one of the fibers had been disconnected from  the c1sus chassis RFM card (its plugged in in the middle of the chassis so its hard to see) during all the plugging in and out of the cables and cards last night.

Problem:

We broke c1sus by moving ADC cards around.

Solution:

We pulled all the cards out, examined all contacts (which looked fine), found 1 poorly connected cable internally, going between an ADC and ADC timing interface card  (that probably happened last night), and one of the two RFM fiber cables pulled out of its RFM card.

We then placed all of the cards back in with a new ordering, tightened down everything, and triple checked all connections were on and well fit.

Gotcha!

Joe forgot that slot 1 and slot 2 of the timing interface boards have their last channels reserved for duotone signals.  Thus, they shouldn't be used for any ADCs or DACs that need their last channel (such as MC3_LR sensor input).  We saw a perfect timing signal come in through the MC3_LR sensor input, which prevented damping. 

We moved the ADC timing interface card out of the 1st slot  of the timing interface board and into slot 6 of the timing interface board, which resolved the problem.

Final Configuration:

 Timing Interface Board

 PCIe Chassis

Still having Issues with:

ITM West damps.  ITM South damps, but the coil gains are opposite to the other optics in order to damp properly.

We also need to look into switching the channel names for the watchdogs on ITMX/Y in addition to the front end code changes.

Problem:

We had not switched the c1aux crates when we renamed the arms, thus the watchdogs labeled ETMX were really watching ETMY and vice-versa.

Solution:

I used telnet to connect to c1auxey, and then c1auxex.

I used the bootChange command to change the IP address of c1auxey to 192.168.113.59 (c1auxex's IP), and its startup script.  Similarly c1auxex was changed to c1auxey and then both were rebooted.

c1auxey > bootChange

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

boot device          : ei
processor number     : 0
host name            : linux1
file name            : /cvs/cds/vw/mv162-262-16M/vxWorks
inet on ethernet (e) : 192.168.113.60:ffffff00 192.168.113.59:ffffff00
inet on backplane (b):
host inet (h)        : 192.168.113.20
gateway inet (g)     :
user (u)             : controls
ftp password (pw) (blank = use rsh):
flags (f)            : 0x0
target name (tn)     : c1auxey c1auxex
startup script (s)   : /cvs/cds/caltech/target/c1auxey/startup.cmd /cvs/cds/caltech/target/c1auxex/startup.cmd
other (o)            :

value = 0 = 0x0

c1auxex > bootChange

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

boot device          : ei
processor number     : 0
host name            : linux1
file name            : /cvs/cds/vw/mv162-262-16M/vxWorks
inet on ethernet (e) : 192.168.113.59:ffffff00 192.168.113.60:ffffff00
inet on backplane (b):
host inet (h)        : 192.168.113.20
gateway inet (g)     :
user (u)             : controls
ftp password (pw) (blank = use rsh):
flags (f)            : 0x0
target name (tn)     : c1auxex c1auxey
startup script (s)   : /cvs/cds/caltech/target/c1auxex/startup.cmd /cvs/cds/caltech/target/c1auxey/startup.cmd
other (o)            :

value = 0 = 0x0

Summary:
   I set Q-values for each ringdown of PRM, BS, ITMX, ITMY, MC1, MC2, MC3 to ~5 using QAdjuster.py.
   Here are the results;


  Red ringdowns indicate the second try after gain setting.

Note:
  - ITMX and ITMY are referred according to MEDM screens in this entry.
  - ITMX(south) OSEM positions are currently so bad(LL and SD are all the way in/out).
        I have to change IFO_ALIGN slider values to check the damping servo. For SIDE, I couldn't do that. I reverted the slider change after the damping checking.
  - ITMY(west) somehow has opposite coil gain sign.
       Usually for the other optics, UL,UR,LR,LL is 1,-1,1,-1. But for ITMY to damp, they are -1,1,-1,1.
  - PRM damps, but ringdown doesn't look nice. There must be something funny going on.
  - SRM doesn't have OSEMs put in now.

The far right monitor in the control room is now displaying IMCR, PMCT, RCR, RCT.

Please note that top left quad is displying PMCT even if the screen is labeled with PMCR.

Control room monitor #13 - #16 had been out of order since the last week.

(the monitor number is shown at : http://lhocds.ligo-wa.caltech.edu:8000/40m/Electronics/VideoMUX )

I found that the connections between camera and the cable to the VIDEO MUX were missing so I connected them.

Initially, PMCT camera was sending its signal to the small monitor on the PSL table.

I splitted the signal so that one signal is going to the small monitor and another is going to the VIDEO MUX.

The "PMCR" is shown on the screen #13 in the control room but it actually showing PMCT camera's signal.

This is a temporary VIDEO configuration. It will be upgraded as well when the whole VIDEO will be upgraded.

I finished the direct measurement of cable impedances.

Moreover, I wrote the cable replacement plan.

The reason I am checking the cables is for replacing the cables with impedance of 50 or 52 ohm by those with impedance of 75 ohm.

After I figures out which cable has not proper impedance, I will make new cables and substitute them in order to match the impedance, which would lead to better VIDEO signal.

Moreover, as Koji suggested, the VIDEO system will be upgraded for better interface.

I measured the cable impedance by checking the reflection ratio at the point connected to the terminator with 50 ohm or 75 ohm.

The orange colored cables are measured to be 75ohm so we do not need to replace them.

Combining the list of cable types and the list of desired length,

I need to make total 37 cables and to remove 10 cables from the current connection.

Detailed plan is attached below.

I currently ordered additional cables and BNC plugs.

From now on, I will keep making CCD cables for VIDEO upgrade.

Then, with your helps, we will replace the CCD cables.

In my opinion, I will finish VIDEO upgrade by this year.

Valera and Haixing and I installed a PMC REFL camera today. We stole the camera control box from the MC2 trans area (because I don't know why we need a camera there).

We installed it such that it is looking at the leak through of the last turning mirror before the PMC REFL RFPD. This beam was previously going into a Thorlabs razor blade dump.

There is no steering mirror to align into this camera; we just positioned the camera such that the REFL beam fills up the monitor. WE cable tied the cable to the table and the

output of the camera control box is piped into the control room correctly as PMCR. The "IMCR" quadrant is actually the PMCT beam. JoonHo is going to fix this promptly.

Also, I noticed how beautiful  the MC2 Simulink diagram is so I post it here for your viewing pleasure. We should take this as a reference and not produce any new diagrams which are less useful or beautiful or easy to understand.

[Koji, Rana, and Kevin]

I have been trying to measure the shot noise of REFL55 by shining a light bulb on the photodiode and measuring the noise with a spectrum analyzer. The measured dark noise of REFL55 is 35 nV/rtHz. I have been able to get 4 mA of DC current on the photodiode but have not been able to see any shot noise.

I previously measured the RF transimpedance of REFL55 by simultaneously measuring the transfer functions of REFL55 and a new focus 1611 photodiode with light from an AM laser. By combining these two transfer functions I calculated that the RF transimpedance at 55 MHz is ~ 200 ohms. With this transimpedance the shot noise at 4 mA is only ~ 7 nV/rtHz and would not be detectable above the dark noise.

The value of 200 ohms for the transimpedance seems low but it agrees with Alberto's previous measurements. By modeling the photodiode circuit as an RLC circuit at resonance with the approximate values of REFL55 (a photodiode capacitance of 100 pF and resistance of 10 ohms and an inductance of 40 nH), I calculated that the transimpedance should be ~ 230 ohms at 55 MHz. Doing the same analysis for the values of REFL11 shows that the transimpedance at 11 MHz should be ~ 2100 ohms. A more careful analysis should include the notch filters but this should be approximately correct at resonance and suggests that the 200 ohm measurement is correct for the current REFL55 circuit.

To clean the glue off the magnets and dumbbells I soaked them in Acetone for about an hour and then scrubbed the ends clean with a lint free tissue soaked in Acetone. 

I then examined the ends under a microscope and found that while the flat faces were clean some of the grooves were still filled with glue.

Top	Bottom

While examining the magnets I found some small magnetic fibers stuck to the magnets.  Rana had mentioned these before as potential trouble makers which could degrade the high frequency performance of the OSEMs.

To try and get the glue out of the grooves I put the dumbells through an ultrasonic bath for ten mins.  Most of the glue has been removed from the grooves.  Pics below

I proceeded try and recover the lost time by sticking the magnets back to the dumbbells.  Increased the quantity of the glue to a slightly larger amount than usual.  It should definitely squish out a bit now.  We will know tomorrow when we open the gluing fixture.

Problem:

c1iscex did not have test points working last night.

Solution:

The diag -i command indicated that :

awg 19 0 192.168.113.80 822095891 1 192.168.113.80

awg 45 0 192.168.113.80 822095917 1 192.168.113.80

The first number after the awg should be the DCUID number.  The IP address 192.168.113.80 corresponds to c1iscex.  So we had awg and testpoints setup for DCUI 19 and 45 on c1iscex.  DCUID 19 is c1x01 (the IOP), but 45 was used for a test awhile back. 

Turns out that in the testpoint.par file located in /cvs/cds/rtcds/caltech/c1/target/gds/param, there were two entries for c1scx, one with DCUID 24 and also DCUID 45.  The model at the time was running with DCUID 24.

So I changed the model DCUID to 45, deleted the [C-node24] entry in the testpoint.par file, and restarted the machine, and also did a "telnet fb 8088" and "shutdown" to restart the frame builder.

RF Transimpedance of 200Ohm means the residual impedance at the resonance (R_res) of 40,
if you consider the amplifier gain (G_amp) of 10 and the voltage division by the 50Ohm termination,
this corresponds to the thermal noise level of Sqrt(4 kB T R_res)*G_amp/2 = 4nV/rtHz at the analyzer, while you observed 35nV/rtHz.

35nV/rtHz corresponds to 7nV/rtHz for the input noise of the preamp. That sounds too big if you consider the voltage noise of opamp MAX4107 that is 0.75nV/rtHz.

What is the measurement noise level of the RF analyzer?

[Jenne, Suresh]

Suresh and I glued the intact-from-the-first-round magnets to ETMU05.  I accidentally got too much glue on one of the dumbbells (the glue was connecting the dumbbell to the gripper - bad news if we let that dry), and while I was cleaning it, the magnet broke off.  So I used one of the ones that Suresh had re-glued last night, and he is putting that one back together after some cleaning. 

To set the fixture, Suresh had the great idea of using small pieces of foil underneath the teflon pads to set the height of the optic in the fixture.  The optic still rests on the teflon pads, but with the foil we have finer control over how the optic sits.  Neat.  Since both ETMs are the same, we shouldn't have to do any more adjustment for the other ETM.

The updated Status Table:

Background:
  c1iscex machine is currently being setup and RT model c1scx is running.
  But ETMX(south) didn't seem to be damped, so I checked it.

What I did:
  1. Checked the wiring. It seemed to be OK.
    Looked LEMO monitor output of SUS PD Whitening Board(D000210) with oscilloscope and they seemed to be getting some sensor signal except SDSEN.
      SDSEN is funny. C1:SUS-ETMX_SPDMon decreases slowly when PD input cable is disconnected, and increases slowly when connected.
      There might be some problem in the circuits.
    Looked LEMO monitor output of SOS Coil Driver Module(D010001) with oscilloscope and they seemed to be receiving correct signal from DAC.
      When ULCOIL offset is added, ch1 increased and so on.

  2. Checked the direction of SUSDOF motion when kicked with one coil.
    The result was;

    This table tells you, when ULCOIL_OFFSET increases, SUSPOS increases and so on.
    If URCOIL and LLCOIL are swapped, they look correct.
    Also, they have opposite sign to the usual optics(e.g. MCs, BS, PRM).

  3. Changed TO_COIL matrix according to the table above(see Attachment #1). Changed signs of XXCOIL_GAINs.

  4. ETMX damped!

Plan:
  - Check the wiring after SOS Coil Driver Module and circuit around SDSEN
  - Check whitening and dewhitening filters. We connected a binary output cable, but didn't checked them yet.
  - Make a script for step 2
  - Activate new DAQ channels for ETMX (what is the current new fresh up-to-date latest fb restart procedure?)

I examined the magnet-dumbbell joints under the microscope to see whether the glue that I applied yesterday was sufficient or in excess.

I think the pictures below speak for themselves !  

During the gluing process the Al dumbbell stays below and the magnet with a drop of glue on the lower face is placed on it and held in the teflon fixture.  As seen in the pics the glue seems to have run up the surface of the magnet and has not collected in the narrow part of the dumbell.  So it has climbed up along the narrow gaps between the magnet and the teflon fixture by capillary action. The glue stops where the teflon fixture ends, a little before reaching the free end of the magnet, which further indicates the capillary action.

(Suresh, Yuta)

If you come up with a good idea and want to add new things to current RT model;

 1. Go to simLink directory and open matlab;
    cd /cvs/cds/rtcds/caltech/c1/core/advLigoRTS/src/epics/simLink
    matlab

 2. In matlab command line, type;
    addpath lib

 3. Open a model you want to edit.
    open modelname

 4. Edit! CDS_PARTS has useful CDS parts.
    open CDS_PARTS
    There are some traps. For example, you cannot put cdsOsc in a subsystem

 5. Compile your new model. See my elog #3787.
 
 6. If you want to burt restore things;
    cd /cvs/cds/caltech/burt/autoburt/snapshots/YEAR/MONTH/DATE/TIME/
    burtgooey

 7. Edit MEDM screens
    cd /cvs/cds/rtcds/caltech/c1/medm
    medm

 8. Useful wiki page on making a new suspension MEDM screens;
    http://lhocds.ligo-wa.caltech.edu:8000/40m/How_to_make_new_suspension_medm_screens

(Suresh, Koji, Yuta)

Background:
  No AWG. No tdssine.
  ...... LOCKIN!

What we did:
  1. Added 2 LOCKINs for c1sus model.
   Currently, we cannot put cdsOsc in a subsystem.
   So, we put LOCKINs just for BS for a test.
   The signal going into LOCKIN can be anything. For now, we just put a matrix for selecting the signal and connected the input signals to the ground.

   See the following page for the current simlink diagram of c1sus model.
     https://nodus.ligo.caltech.edu:30889/FE/c1sus_slwebview_files/index.html

  2. Edited MEDM screens. (see Attachment #1)

Result:
  We succeeded in putting 2 LOCKINs and exciting BS.
  During the update, we might destroyed things. For example, fb status is red in GDS screens.
  We will wait for Joe to fix them.

Plan:
 - Fix cdsOsc and put LOCKINs for all the other optics
 - Come up with a good idea what to do with this LOCKIN. Remember, LOCKIN is not just a replacement for excitation points.
 - Enhance an oscillator so that we can put a random noise

(Koji, Joe, Yuta)

Motivation:
  We wanted to know more about CDS.

Setup:
  Same as in elog #3829.

What we did:
  1. Made test RT models c1tst and c1nio for c1iscex.
     c1tst has only 2 filter module(minimum limit of a model), 2 inputs, 2 outputs and it runs with IOP c1x01.
     c1nio is the same as c1tst except it runs(or, should run) without IOP.

  2. Measured the time delay of ADC through DAC using different machine, different sampling rate by measuring transfer functions.

  3. c1nio(without IOP) didn't seem to be running correctly and we couldn't measure the TF.
     "1 PPS" error appeared in GDS screen(C1:FEC-39_TIME_ERR).
     It looks like c1nio is receiving the signal as we could see in the MEDM screen, but the signal doesn't come out from the DAC.

TF we expected:
  All the filters and gains are set to 1.

  We have DA's TF when putting 64K signal out to analog world.
    D(f)=exp(-i*pi*f*Ts)*sin(pi*f*Ts)/(pi*f*Ts)  (Ts: sample time)

  We have AA filter and AI filter when downsampling and upsampling.
    A(f)=G*(1+b11/z+b12/z/z)/(1+a11/z+a12/z/z)*(1+b21/z+b22/z/z)/(1+a21/z+a22/z/z)       z=exp(i*2*pi*f*Ts)
  Coefficients can be found in /cvs/cds/rtcds/caltech/c1/core/advLigoRTS/src/fe/controller.c.

/* Coeffs for the 2x downsampling (32K system) filter */
static double feCoeff2x[9] =
        {0.053628649721183,
        -1.25687596603711,    0.57946661417301,    0.00000415782507,    1.00000000000000,
        -0.79382359542546,    0.88797791037820,    1.29081406322442,    1.00000000000000};
/* Coeffs for the 4x downsampling (16K system) filter */
static double feCoeff4x[9] =
    {0.014805052402446, 
    -1.71662585474518,    0.78495484219691,   -1.41346289716898,   0.99893884152400,
    -1.68385964238855,    0.93734519457266,    0.00000127375260,   0.99819981588176};

  For 64K system, we expect H=1.

  We also have a delay.
    S(f)=exp(-i*2*pi*f*dt)   (dt: delay time)

  So, total TF we expect is;
    H(f)=a*A(f)^2*D(f)*S(f)
  a is a constant depending on the range of ADC and DAC(I think). Currently, a=1/4.

  We may need to think about TF when upsampling.(D(f) is TF of upsampling 64K to analog)

Result:
  Example plot is attached.
  For other plots and the raw data, see /cvs/cds/caltech/users/yuta/scripts/CDSdelay2/ directory.
  As you can see, TFs are slightly different from what we expect.
  They show ripple we don't understand at near cut off frequency.

  If we ignore the ripple, here is the result of delay time at each condition;

data file    host    FE    IOP        rate    sample time    delay        delay/Ts
c1rms16K.dat    c1sus      c1rms    adcSlave    16K    61.0usec    110.4usec    1.8
c1scx16K.dat    c1iscex    c1scx    adcSlave    16K    61.0usec     85.5usec    1.4
c1tst16K.dat    c1iscex    c1tst    adcSlave    16K    61.0usec     84.3usec    1.4
c1tst32K.dat    c1iscex    c1tst    adcSlave    32K    30.5usec     53.7usec    1.8
c1tst64K.dat    c1iscex    c1tst    adcSlave    64K    15.3usec     38.4usec    2.5

  The delay time shown above does not include the delay of DA. To include, add 7.6usec(Ts/2).

  - delay time is different for different machine
  - number of filters (c1scx has full of filters for ETMX suspension, c1tst has only 2) doen't seem to effect much to delay time
  - higher the sampling rate, larger the (delay time)/(sample time) ratio

Plan:
 - figure out how to run a model without IOP
 - where do the ripples come from?
 - why we didn't see significant ripple at previous measurement on c1sus?

I've updated the  Computer Restart Procedures  page in the wiki with the latest fb restart procedure.

To just restart just the daqd (frame builder) process, do:

1) telnet fb 8088

2) shutdown

The init process will take care of the rest and restart daqd automatically.

CDS Objectives for the Week:

Monday/Tuesday:

1) Investigate ETMX SD sensor problems

2) Fully check out the ETMX suspension and get that to a "green" state.

3) Look into cleaning up target directories (merge old target directory into the current target directory) and update all the slow machines for the new code location.

4) Clean up GDS apps directory (create link to opt/apps on all front end machines).

5) Get Rana his SENSOR, PERROR, etc channels.

Tuesday/Wednesday:

3) Install LSC IO chassis and necessary cabling/fibers.

4) Get LSC computer talking to its remote IO chassis

Wednesday:

5) If time, connect and start debugging Dolphin connection between LSC and SUS machines

Problem:

The CDS oscillator part doesn't work inside subsystems.

Solution:

Rolf checked in an older version of the CDS oscillator which includes an input (which you just connect to a ground).  This makes the parser work properly so you can build with the oscillator in a subsystem.

So I did an SVN checkout and confirmed that the custom changes we have here were not overwritten.

Edit:

Turns out the latest svn version requires new locations for certain codes, such as EPICS installs.  I reverted back to version 2160, which is just before the new EPICs and other rtapps directory locations, but late enough to pick up the temporary fix to the CDS oscillator part.

Problem:

c1iscex does not even see its 32 channel Binary output card.  This means we have no control over the state of the analog whitening and dewhitening filters.  The ADC, DAC, and the 1616 Binary Input/Output cards are recognized and working.

Things tried:

Tried recreating the IOP code from the known working c1x02 (from the c1sus front end), but that didn't help.

Checked seating of the card, but it seems correctly socketed and tightened down nicely with a screw.

Tomorrow will try moving cards around and see if there's an issue with the first slot, which the Binary Output card is in.

Current Status:

The ETMX is currently damping, including POS, PIT, YAW and SIDE degrees of freedom.  However, the gds screen is showing a 0x2bad status for the c1scx front end (the IOP seems fine with a 0x0 status).  So for the moment, I can't seem to bring up c1scx testpoints.  I was able to do so earlier when I was testing the status of the binary outputs, so during one of the rebuilds, something broke. I may have to undo the SVN update and/or a change made by Alex today to allow for longer filter bank names beyond 19 characters.

[Suresh, Jenne]

A story about minor disasters, and crises averted:

Once upon a time, in a cleanroom not so far away..... there lived an optic.  To preserve anonymity, we shall call him "ETMU05".  This optic had a rough day.  When removing the grippers from the magnet-to-optic fixture, 4 out of 6 magnets broke off the dumbbells (the dumbbells were still securely glued to the optic...these had come out of the same batch that had problems last week, same problem).  The remaining 2, LL and LR, were sadly of the same polarity.  This is bad, because it means that the "humans" taking care of "ETMU05" didn't check the polarity of the face magnets properly, and ensure that they were laid out in an every-other pattern (LL and UR having the same polarity, and LR and UL having the opposite).  So, the humans removed all magnets and dumbbells from ETMU05.  All remaining glue was carefully scrubbed off the surfaces of ETMU05 using lens paper and acetone, and the magnets and dumbbells were sonicated in acetone, scrubbed with a lint-free wipe, sonicated again, and then scrubbed again to remove the glue.  ETMU05 had a nice cleansing, and was drag wiped on both the AR and HR surfaces with acetone and iso.  ETMU05 is now on vacation in a nice little foil hut.

His friend, (let's call him ETMU07) had a set of magnets (with polarities carefully confirmed) glued to him.  The cleaned magnets and dumbbells removed from ETMU05 were reglued to their dumbbells, and should be dry by tomorrow. 

.....And then they lived happily ever after.  The End.

The revised schedule / status table:

 I disconnected the yellow GPIB box from the backside of HP3563A (classic analyzer),

and connected it to AG4395A (network analyzer), which is the official place for it.

 As I said in the past entry (see this entry), there was unknown loss of about 20dB in the beat detection path.

So I started fully characterizing the beat detection path. 

Today I measured the frequency response of the wideband RFPD using the Jenne Laser.

Since all the data were taken by using a 1064nm laser, the absolute magnitudes [V/W] for 532nm are not calibrated yet.  

I will calibrate the absolute values with a green laser which has a known power.

The data were taken by changing the bias voltage from -150V to 0V.

The shape of the transfer function looks quite similar to that Hartmut measured before (see the entry).

It has 100MHz bandwidth when the bias voltage is -150V, which is our normal operation point.

Theoretically the transfer function must keep flat at lower frequency down to DC.

Therefore for the calibration of this data, we can use the DC signal when a green beam with a known power is illuminating the PD.

I measured the RF transimpedance of the POX photodiode by measuring the optical transfer function with the AM laser and by measuring the shot noise with a light bulb. The plots of these measurements are at http://lhocds.ligo-wa.caltech.edu:8000/40m/Electronics/POX.

I measured the noise of the photodiode at 11 MHz for different light intensities using an Agilent 4395a. The noise of a 50 ohm resistor as measured by this spectrum analyzer is 10.6 nV/rtHz. I fit this noise data to the shot noise formula to find the RF transimpedance at 11 MHz to be (2.42 ± 0.08) kΩ. The RF transimpedance at 11 MHz as measured by the transfer function is 6.4 kΩ.

As a part of the characterization works, I measured the spectra of the RFPD noise as well. 

The noise is totally dominated by that of the RFPD (i.e. not by an RF amplifier).

I am going to check the noise curve by comparing with a LISO model (or a simple analytical model) in order to make sure the noise is reasonable.

 (results) 

The red curve represents the dark noise of the RFPD, which is amplified by a low noise amp, ZFL-1000LN.

The blue curve is a noise of only ZFL-1000LN with a 50 Ohm terminator at its input.

The last curve is noise of the network analyzer AG4395A itself.

It is clear that the noise is dominated by that of RFPD. It has a broad hill around 100MHz and a spike at 16MHz.

(notes)

Gain of ZFL-1000LN   = 25.5 dB (measured)

Applied voltage to ZFL-1000LN = +15.0 V

Bias voltage on PD = -150 V

[Kiwamu/Koji]

- The tanks are open

Plan

[done] - Remove the PZT cable currently underlying between BS and ITMY chambers
[done] - Put this PZT cable between BS and IMC chambers. Connect it on the PZT on the IMC table (SM1)
[done]- Put the two OSEM cables between BS and ITMY chambers. Connect this cable to SRM.
  The connector for this cable at the BS side is coming from Bob's place on Wednesday. We left it disconnected for now.

- Energize all of four PZTs and check the functionality.

Problem:

Front ends seem to be experiencing a timing issue.  I can visibly see a difference in the GPS time ticks between models running on c1ioo and c1sus. 

In addition, the fb is reporting a 0x2bad to all front ends.  The 0x2000 means a mismatch in config files, but the 0xbad indicates an out of sync problem between the front ends and the frame builder.

Plan:

As there are plans to work on the optic tables today and suspension damping is needed, we are holding off on working on the problem until this afternoon/evening, since suspensions are still damping.  It does mean the RFM connections are not available.

At that point I'd like to do a reboot of the front ends and framebuilder and see if they come back up in sync or not.

Winter Cleaning:

I cleaned up the /cvs/cds/caltech/target/ directory of all the random models we had built over the last year, in preparation for the move of the old /cvs/cds/caltech/target slow control machine code into the new /opt/rtcds/caltech/c1/target directories.

I basically deleted all the directories generated by the RCG code that were put there, including things like c1tst, c1tstepics, c1x00, c1x00epics, and so forth.  Pre-RCG era code was left untouched.

The last time(Friday) I made an arrangement for RF distribution unit.

I am making RF distribution unit for RF upgrade which is designed by Alberto.

To reduce a noise from loose connection,

I tried to make the number of hard connect as much as possible while reducing the number of connection via wire.

This is why I put splitters right next to the front pannel so that the connection between pannel plugs and splitters could be made of hard joints.

I attached the arrangement that I made on the last Friday.

Next time, I will drill the teflon(the supporting plate) for assembly.

Any suggestion would be really appreciated.

Joe showed me what was what with adding DAQ channels, and I have begun building a simulink model to acquire the PEM channels. 

My models is in: /cvs/cds/rtcds/caltech/c1/core/advLigoRTS/src/epics/simLink/c1pem.mdl

Next on the to do list in this category: test which input connector goes with which channel (hopefully it's linear, exactly as one would think), and give the channels appropriate names. 

Updated Apps:

I created a new setup script for the newest build of the gds tools (DTT, foton, etc), located in /opt/apps (which is a soft link from /cvs/cds/apps) called gds-env.csh.

This script is now sourced by cshrc.40m for linux 64 bit machines.  In addition, the control room machines have a soft link in the /opt directory to the /cvs/cds/apps directory.

So now when you type dtt or foton, it will bring up the Centos compiled code Alex copied over from Hanford last month.

[Koji, Jenne]

ETMU07 had its wire winched to the correct height, was balanced, standoff glued.  Can be ready for going into the oven tomorrow, if an oven is available.  (One of Bob's ovens has a leak, so he's down an oven, which puts everything behind schedule.  We may not be able to get anything into the oven until Monday).

ETMU05 had magnets glued to the optic.  Hopefully tomorrow we will winch the wire and balance the optic, and glue the standoff, and be ready to go into the oven on Monday.

The spring plungers were sonicated, but have not yet been baked.  I told Daphen that we'd like the optics baked first, so that we can get ETMX in the chamber ASAP, and then the spring plungers as soon as possible so that we can install ETMY and put the OSEMs in.

The updated status table:

 [Suresh, Kiwamu]

We found that two of three PZT mirrors are at wrong place in the chambers.

Therefore we have to move these PZT mirrors together with their connections.

Here is a diagram for the current situation and the plan.

  Basically mirror (A) must be associated to the output beam coming out from the SRM, but it was incorrectly put as a part of the input optics.

Similar to that, mirror (C) must belong to the input optics, but it is incorrectly being used as a part of OMC stuff.

Therefore we have to swap the positions of mirror (A) and mirror (C) as shown in the diagram above.

In addition to the mirror immigration, we also have to move their cables as well in order to keep the right functions.

 We took a look at the length of the cables outside of the chambers in order to check if they are long enough or not.

And we found that the cables from c1asc (green line in the diagram) is not long enough, so we will put an extension D-sub cable.

I installed and activated Altium, a PCB design software, on the Windows machine M2.

With Altium I am going to design the triple resonant circuit for the broadband EOM.

 [Joe, Suresh, Kiwamu]

 We will fully install and run the new C1LSC front end machine tomorrow.

And finally it is going to take care of the IOO PZT mirrors as well as LSC codes. 

 (background stroy)

 During the in-vac work today, we tried to energize and adjust the PZT mirrors to their midpoints.

However it turned out that C1ASC, which controls the voltage applying on the PZT mirrors, were not running.

We tried rebooting C1ASC by keying the crate but it didn't come back.

 The error message we got in telnet  was :

   memory init failure !!

 We discussed how to control the PZT mirrors from point of view of both short term and long term operation.

We decided to quit using C1ASC and use new C1LSC instead.

A good thing of this action is that, this work will bring the CDS closer to the final configuration. 

(things to do)

 - move C1LSC to the proper rack (1X4).

 - pull out the stuff associated with C1ASC from the 1Y3 rack.

 - install an IO chasis to the 1Y3 rack.

- string a fiber from C1LSC to the IO chasis.

- timing cable (?)

- configure C1LSC for Gentoo

- run a simple model to check the health

- build a model for controlling the PZT mirrors

Wow. I typed DTT on rossa and it actually worked! No complaints about testpoints, etc. I was also able to use its new 'NDS2' function to get data off of the CIT cluster (L1:DARM_ERR from February). You have to use the kinit/kdestroy stuff to use NDS2 as usual (look up NDS2 in DASWG if you don't know what I mean).