ELOG 40m

Name server and Epics

The problems Rob was experiencing last night was due to part of the setup (or rather testing of the setup) of the new nameserver running on linux1.

The name server was setup on linux1 by doing the following:

1) Installed xorg-x11-xauth via yum which was necessary to get remote x windows to work in linux1

2) Installed xorg-x11-fonts-Type1 in order to get the gui system-config-* programs to work

3) Ran system-config-bind, which created a default set of nameserver files. I unfortunately didn't understand the gui all that well, so I manually edited and added files to these base ones. The base files were generated in /var/named/chroot/etc/ and /var/named/chroot/var/named.

4) I added martian.zone and 113.215.131.in-addr.arpa.zone, named.conf.local, and edited named.conf so it loaded named.conf.local. The martian.zone file acts a forward look up (i.e. give it a name and it returns an IP number like 131.215.113.20). The 113.215.131.in-addr.arpa.zone acts as a reverse look up (i.e. give it an IP number like 131.215.113.20 and it tells you the name). The file named.conf.local merely points to these two files.

Note: One can add or change IP lookup by simply updating these two files. The format should be obvious from the files.

5) I specifically ssh'd in as root to linux1 (using su wasn't sufficient) and then typed "service named start" (without quotes). You can also use "restart" or "stop" instead of "start". This started the name server, giving an [Ok] message.

6) I edited the /etc/resolve.conf file on linux1 so that it pointed to itself first ("nameserver 127.0.0.1" at the top of the file). I also added the line "search martian", which allows one to simply use linux1 as opposed to linux1.martian.

I also edited the /etc/resolve/conf file on linux2, and it seems to resolve names fine.

7) And here is where I broke things. As a test, I moved /etc/hosts to /etc/hosts.bak, and then tested to see if names were being resolved correctly. By using the command host, I determined they were in fact working. I also tested with ssh.

However, something basic didn't like me moving the hosts file. Apparently when a front-end machine needed to reboot, it wouldn't come back up, without any ability to SSH or telnet into them.

With Yoichi and I did quite a bit of debugging this morning and determined the nameserver itself isn't conflicting, merely the lack of the host file was the source of the problem. One theory is that services don't know to go to DNS to resolve host names. I think by modifying the /etc/nsswitch.conf file to include dns as an option for services and other programs, it might work without the host file, however, I'm going to leave that to tomorrow morning which is less likely to interfere with current operations.

As it stands, things are working with the nameserver running and the host file in place.

973

Fri Sep 19 11:21:45 2008

Nameserver and Rosalba

I tried modifying the nsswitch.conf file to include going to dns in addition to local files for everything (services, network, etc) and then moving the /etc/hosts file to /etc/hosts.bak. Unfortunately, this still didn't allow front-ends to reboot properly. So I'm not sure what is using the hosts file, but whatever it is, is apparently important. After the test I placed the hosts file back and reverted the nsswitch.conf file.

I also noticed that Rosalba was having problems connecting to the network. This apparently was because I had shut down the dhcp server on the NAT router, as had been discussed at the meeting on Wednesday.

To fix this, I modified the /etc/sysconfig/network-scripts/ifcfg-eth1 file to fix rosalba's ip as 131.215.113.24 (which doesn't seem to be in use). I also updated rosalba's /etc/resolv.conf file to point at linux1's name server, and two additional name servers as well, and added the "search martian" line. I modified the /etc/sysconfig/network-scripts/ifcfg-eth0 file so the built in network card doesn't come up automatically, since its currently not plugged into anything. Lastly, I added rosalba and its IP to linux1's name server files.

980

Mon Sep 22 21:30:06 2008

The MC refl power was going up and the FSS PC drive was so large that I had to turn up the FSS
common gain from 1.5 dB to 10.5 dB to get it to be better. Attached are the before (REF) and
after plots of frequency noise. Is the FSS gain really supposed to be 1.5 dB?? How did we gain
so many dB's of optical gain? Is there a loop measurement from after Peter's oscillator change?

Attachment 1: DAQ.png

982

Mon Sep 22 22:24:19 2008

Quote:

The MC refl power was going up and the FSS PC drive was so large that I had to turn up the FSS...

Looks like I bumped the PS for the 21.5 MHz test setup and changed the supply voltage of the amplifier
from +24 to +38 V. This made the amplifier go hot after a few hours and the output eventually dropped.

Yoichi and I walked out there now and it was too hot to touch. We turned it off and put it on a heat
sink to make it chill out and it came back after a few minutes. We have set the input to the amp to
be -7 dBm instead of -8 dBm after deciding that we should take into account the 1 dB loss in the cable
run and deliver a real +17 dBm to the mixer.

The right way is to calibrated the LO mon of the FSS.

986

Tue Sep 23 15:28:06 2008

new 21.5 MHz FSS reference installed

The new 21.5 MHz FSS reference is now installed in the rack with the 7 Sorensen PS. Both outputs give 18.7 dBm. The MC seems happy.

Bob did the +24 V and +15 V hookups for the amp and the Wenzel oscillator respectively, off of the din strips on the right of the rack.

I have attached two photographs. One shows the front of the box as mounted in the rack, and the other shows the inside of the box. From the second photo the circuit is apparent. Black wire coming in has ground, green has +15, and white has +24. After the switches, ground and +15 go to the Wenzel crystal oscillator, and ground and +24 go to the mini-circuits amp. There is 5 dB attenuation between the Wenzel 21.5 MHz output and the amp input. There is 3 dB attenuation between the amp output and the splitter.

The Wenzel crystal oscillator is their "streamline" model, and puts out 13.2 dBm. The amp is mini-circuits ZHL-2.

Attachment 1: fss_ref_001.jpg

Attachment 2: fss_ref_013.jpg

988

Wed Sep 24 19:13:06 2008

Computer Scripts / Programs

updatedb & locate: megatron & rosalba

I ran updatedb as root today on megatron and rosalba just before the meeting.
It finished at ~14:10 on both machines so that's ~20 minutes total.

The default updatedb.conf for these guys also seems to be set up right so that
it is indexing the NFS mount (/cvs/cds/) so that's good. Next, someone needs to
add the updatedb command to the daily cron for each of these guys (5 AM) and
add this to the wiki page on how we set up new computers.

I also found that the root passwd on Megatron was different from all of the other
machines, indicating that perhaps megatron was trying to free himself. I have put
down that rebellion viciously:D and he's now toeing the line.

992

Thu Sep 25 14:03:08 2008

Quote:

We (Joe) need to buy a GigE card for linux1 and to also set up conlog and conlogger to run on Nodus.

A spare Intel Pro 1000/GT desktop adapter (gigabit ethernet card) has been added to Linux1 and is now using that card to connect to the network.

This was after a slight scare when I somehow reset the bios on Linux1 during the first reboot after adding the card.
After some debugging and discussion with Yoichi, the bios was fixed and the computer works again, with its new faster network connection.

Although we both noted that Linux1 is a rather old machine, with only half a gig of Ram and reaching about 80% capacity on its 58 gigabyte hard drive (raid). Might be worth upgrading in general.

Need to figure out how to install conlog/conlogger programs next...

994

Thu Sep 25 17:14:31 2008

Attachment 1: vegemite.png

997

Fri Sep 26 14:10:21 2008

Lab laptops maintenance

The linux laptops were unable to write to the NFS mounted directories.
That was because the UID of the controls account on those compters was different from linux1 and other control room computers.
I changed the UID of the controls account on the laptops. Of course it required not only editing /etc/password but also dealing with
numerous errors caused by the sudden change of the UID. I had to chown all the files/directories in the /home/controls.
I also had to remove /tmp/gconf-controls because it was assigned the old UID.

Whenever we add a new machine, we have to make sure the controls account has the same UID/GID as other machines, that is 1001/1001.

I did some cleanups of the laptop environment.
I made dataviewer work on the laptops *locally*. We no longer have to ssh -X to other computers to run dataviewer.
The trick was to install grace using Fedora package by

sudo yum install grace

Then i modified /usr/local/stow_pkgs/dataviewer/dataviewer to change the option to dc3 from "-s fb" to "-s fb40m".

1001

Fri Sep 26 19:08:43 2008

Refcav Trans: PD + Camera + Dumps

I went out to improve the Refcav trans path.

I removed all ND filters to get rid of the fringing.

I removed the anodized Al dump that was there. Black anodized Aluminum dumps are forbidden for use as
dumps in any low phase noise setup (such as our frequency stabilization cavity). The scatter was going
directly back into the cavity and making noise. For now its undumped, but Steve will find the
reflections and dump them on unblemished razor blade dumps mounted stiffly.

I will post a photo of the new setup later - the new setup is sketched on the control room markerboard.

The transPD level is now 8 V, up from its previous 3-4 V. We will probably have to also put a lens
in front of it to get the beam size down.

1006

Mon Sep 29 13:33:39 2008

Gigabit network finished and conlog available on Nodus

The last 100 Mb unmounted hub has been removed (or at least of the ones I could find). We should be on a fully gigabit network with Cat6 cables and lots and lots of labels.

In other news, the pearl script that runs the web interface on linux1 for the conlog has been copied to /cvs/cds/caltech/apache/cgi-bin/ and is now being pointed to by the apache server on Nodus.

https://nodus.ligo.caltech.edu:30889/cgi-bin/conlog_web.pl

1015

Wed Oct 1 12:05:58 2008

Alberto

"StochMon" added to the Alarm Handler

John, Alberto,

we added the four channels of the RF Amplitude Monitor (aka StochMon) to the Alarm HAndler. First we modified the 40m.alh file just copying some lines and switching the name of the channels to the ones we wanted. Than we also added a few lines to the database file ioo.db in order to define the alrm levels. So far I used just test values for the thresholds of green, yellow and red states and need to update to some reasonable ones. To do that I need to calibrate those EPICS channels. I have the old data saved and I'm now trying to figure out how to properly change the database file.

1016

Wed Oct 1 12:09:25 2008

Alberto

"StochMon" added to the Alarm Handler

Quote:

John, Alberto,

we added the four channels of the RF Amplitude Monitor (aka StochMon) to the Alarm HAndler. So far I used just test values for the thresholds of green, yellow and red states and need to update to some reasonable ones. To do that I need to calibrate those EPICS channels. I have the old data saved and I'm now trying to figure out how to properly change the database file.

John, Yoichi, Alberto

We restarted the C1iool0 computer both directly by the main key and remotely via telnet. We had to do it a couple of times and in one occasion the computer didn't restart properly and had connection problem with the newtowrk. We had to call Alex that did just the same thing, but used the CTRL+X command to reboot. It worked and the Alarm Handler now includes the StochMon.

1018

Wed Oct 1 23:21:03 2008

Reference cavity reflection camera

I re-centered the reference cavity reflection camera, which has been mis-aligned for a while.
I also tweaked an input steering mirror to make the alignment better. This resulted in the increase of the transmission PD voltage
from 8V to 9V.

1022

Fri Oct 3 12:15:21 2008

This morning, in order to update the threshold values of the alarm handler for the StochMon, I rebooted the C1iool0 computer following the procedure in the wiki, that is telnetting on it and typing CTRL+X. Apparently everything went well in the process.

1031

Tue Oct 7 12:17:57 2008

Yoichi, Alberto

I noticed the MEDM screen time was about 7 minutes ahead of the right time. The time on MEDM is read on channel C0:TIM-PACIFIC_STRING which takes it from the C1VCU-EPICS computer. Yoichi found that that computer did not have the right time because one of the startup scripts, ntpd, which are contained in the directory /etc/init.d/ for some reason did not start. So restring it by typing ./ntpd start updated the time on that computer and fixed the problem.

1033

Wed Oct 8 12:35:56 2008

New Network diagram for the 40m

Attached is a pdf of the new network diagram for the 40m after having removed all of the old hubs.

Attachment 1: 40m_network_10-07-08.pdf

1034

Wed Oct 8 19:17:55 2008

Laser power is slowly recovering

This afternoon we (rich, steve, yoichi) shutdown the laser for the DC-DC converter installation.
(we decided not to do so. Detail will be posted soon.)
After we turned on the laser again,the laser power has been recovering but very slowly.
At the time of writing, the laser power is 2.6W (MOPA_AMPMON).
I think it is because the chiller temparature has not yet settled down (it went up to 25C and slowly coming down, now at 22C).
It will take some hours until the power fully comes back.
Right now I confirmed that at least the MC locks.

1036

Wed Oct 8 22:23:43 2008

Electronics work bench cleanup

Electronics

Yesterday, I cleaned up the electronics work bench. I figured that keeping the work bench
in order has larger effect on the work efficiency than buying expensive soldering stations.
Whoever works there should clean up the table after the work to the state shown on
the right side of the picture (at least).
If you leave the bench for a while (more than 30min) but intend to return later and
resume the work, please write your name and time on a piece of paper and put it on the bench.
Otherwise, your stuff can be taken away anytime.

Attachment 1: Cleanup.jpg

1041

Fri Oct 10 20:03:35 2008

medm, dataviewer, dtt on 64 bit linux

I compiled EPICS (base, medm and ezca) and dataviewer for 64 bit linux.
These are installed in /cvs/cds/caltech/apps/linux64/.
I also configured cshrc.40m to make it possible to run the 32bit dtt on 64bit machines.
64bit ligotools is also installed to /cvs/cds/caltech/apps/linux64/ligotools although I haven't tested it extensively.

With those essential tools available for 64bit linux, Joe and I decided to install 64bit CentOS to the new linux machine.
It is named allegra.
Now, medm, dataviewer, dtt, awg, foton and ezca commands all work on rosalba and allegra.
I put some notes on how to make things work on 64bit in the wiki.
http://lhocds.ligo-wa.caltech.edu:8000/40m/Building_LIGO_softwares_for_64_bit_linux

I compiled dtt (actually the whole GDS tree) for 64bit linux and the build process finished normally.
But somehow dtt does not work properly. It starts on my laptop but does not retrieve data. It crashes on rosalba.
So I had to retreat to 32bit.

1043

Mon Oct 13 13:51:49 2008

attempt to measure FSS ref phase

On Friday I began a measurement of the FSS reference phase. The setup involves the following:
+ turn off the 166 MHz LO (top signal generator on 1Y2 rack)
+ bring FSS LO 21.5 MHz to the 166 MHz delay line phase shifter, and back out the phase shifter with a second length of cable
+ add a length of cable to the RF 21.5 MHz in preparation for measuring FSS IN2 as a function of delay

Trouble locking the FSS, and ran out of time before the measurement could be performed.

1046

Tue Oct 14 14:19:36 2008

Today I made several measurements which should yield the optimized phase for the FSS 21.5 MHz reference. I made two sets of measurements, using the 166 MHz phase delay shifter. For each phase value I made 5 measurements of a 500 kHz injection into test2 at 1 Vpp, with the 4195 spectrum analyzer on in1 with the high impedance probe, 51 points, a 10 kHz range. It was surprisingly noisy. I will make plots using matlab to find the maximum, and hope for consistent results between the two sets of measurements. If it is too noisy or inconsistent I will repeat the measurement at ~800 kHz.

Once I find the phase which yields peak amplitude in in1, I will measure the relative phase between LO and RF going in to the FSS, measure the speed of light in RG58 cable, and construct a new cable which will implement the desired relative phase.

1048

Tue Oct 14 19:24:34 2008

FSS light power reduced

Rana, Yoichi

To change the gain distribution in the FSS, Rana reduced the VCO power for the AOM to reduce the light incident to the reference cavity.
Now the transmitted power of the RC is 2.3V compared to 6.5V before.
The FSS common gain can be increased to 5dB. I haven't changed the normal gain for this slider, so the mcup script will still set
the common gain to 1.5dB after an MC lock.
With this change, we take some gain from the optical part and give more gain in the electronics.
This might relieve the slew rate limit problem if it is happening in an early stage of the electronics.

1050

Wed Oct 15 22:07:52 2008

FSS ref phase measurements

Optimizing the FSS LO/RF phase at 500 kHz, above the servo band, proved to be noisy and those measurements were useless. Today I repeated
the measurement at 35 kHz and got good signal to noise. I've attached a plot of the 35 kHz peak in dBm as measured at IN2 by SR785, with
an injection into TEST2 at 35 kHz with 0.2 Vpp, as a function of delay in ns given by the delay phase shifter normally used by the 166 MHz.
I fit the bottom (quadratic) portion of this curve, and found an optimum delay of 25.8 ns, which can be implemented as 25.81 ns on the phase
shift box (25 + 1/2 + 1/4 + 1/16). This is an uncalibrated number and meaningless.. For all these measurements a very long SMA cable
(did not measure) was inserted on the RF output of the 21.5 MHz reference box. The actual phase difference depends on these cable lengths
which I didn't measure.

To determine the actual phase difference I compared the LO and RF input points with the 25.81 ns delay, using a scope with poor man's
averaging (33 manual triggers and recording the phase measurements). The phase difference was 8.24 degrees with an error on the mean of 3.4%,
with the LO having the longer effective cable (cable plus delay from the phase delay box). As a sanity check I set the phase delay box
to 20 ns and re-measured, and found 49.5 degrees. (1/21.5 MHz) * (49.5-8.24)/360 = 5.3 ns, which is about the difference between 20 ns
and 25.81 ns. I did the same with 0 ns dialed in, and found a difference of 21.5 ns (I expected 25.8 ns). So it is possible that the
phase delay box isn't too precise.

Finally, to determine the length of cable needed to implement 8.24 degrees of phase at 21.5 MHz with RG58 cable, I made some phase measurements
using the FSS reference box and mismatched cables. I used three cable lengths (93 cm, 140.5 cm, and 169.5 cm ) and two mismatched pairs with
dL of 29 and 76.5 cm. For each pair I took average of 20 measurements, finding 22.54 degrees mean for the dL=29 cm pair (0.78 degrees/cm, or
a speed of light of 1.0e10 cm/s, or 10.6 cm of cable length on the LO) and 43.57 degrees mean for dL=76.5 cm pair (0.57 degrees/cm, or a speed
of light of 1.4e10 cm/s, or 14.5 cm of cable length on the LO). I expected more precise agreement.

Maybe the 21.5 MHz reference box is not zero phase between the outputs. This could be easily tested. It might be interesting to repeat this
measurement with a few more dL values.

Attachment 1: phasedelay.png

1052

Thu Oct 16 09:47:49 2008

FSS ref phase measurements

Quote:

I fit the bottom (quadratic) portion of this curve, and found an optimum delay of 25.8 ns, which can be implemented as 25.81 ns on the phase shift box (25 + 1/2 + 1/4 + 1/16).

The gain of the loop is sinusoidally dependent on the phase delay. So the fit will be better with a function like this: 1/(1+G*sin(dphi + const)).

1053

Thu Oct 16 13:12:58 2008

phase between FSS reference outputs

I verified the phase between the FSS reference outputs (used for LO and RF) using matched BNC cables. I measured 0.95 degree (average of 12 scope measurements).

1054

Thu Oct 16 16:26:26 2008

FSS phase matching cable installed

RG 405 cable has a solid teflon dielectric, and a velocity factor of 0.69. To get the 8.2 degrees of additional phase on the LO output at 21.5 MHz then requires 22 cm of cable. I made a cable that ended up being 21 cm long after I'd gained some experience putting on the connector. It gives a phase difference between LO and RF of about 10 degrees. It is currently installed.

1055

Fri Oct 17 16:43:10 2008

mcup/down scripts on linux

I made some changes to /cvs/cds/caltech/medm/c1/ioo/cmd/medmMCup and medmMCdown so that those can be run from medm on linux machines.

1059

Mon Oct 20 15:02:00 2008

I moved missing files in /cvs/cds restored by Alan and Stuart to the original locations.
I confirmed autoburt runs, and dtt, which had also been having trouble running, runs ok now.

I found an interesting piece of evidence on allegra, our new 64bit linux machine.
In the Trash of controls Desktop on that machine, there is /cvs/cds/vw/ directory.
I remember that when I last time emptied the trash bin on the machine (yesterday), it took somewhat long time.
Too bad that I did not pay attention to what was actually in the Trash, but now I have a feeling that in the Trash were
missing /cvs/cds/* directories.
While emptying the Trash, I encountered several errors saying permission denied or something like that, and skipped those files.
Sometimes, when you move something from NFS mounted directories to the Trash, you get this kind of errors.
So my guess is that someone accidentally (or intentionally) moved /cvs/cds/* except for "caltech" to the Trash of allegra.
And I completely removed them carelessly.

1060

Mon Oct 20 16:18:00 2008

Quote:

In the meantime, I have re-started the nightly backup for /frames/minute-trends
but NOT YET for /cvs/cds ,
since I fear that we'll find another problem and will need to go back to the June 27 backup.
Let's wait a few days for the dust to settle,
and if everyone feels confident that /cvs/cds is ok,
I'll restart the backup of that.

How I restored the files, for the record:

Stuart mounted /archive/backup onto an accessible computer (garrak.ligo.caltech.edu ) and I logged on to controls@nodus and ran this command:

/cvs/cds/caltech/scripts/backup/rsync --rsync-path=/usr/bin/rsync --rsh=/usr/bin/ssh --compress --verbose --archive --hard-links --exclude=caltech/ ajw@garrak.ligo.caltech.edu:/backup/40m/cvs /cvs/cds/recover_20081020

I had to type in my GC password, and it ran for ~20 minutes (would have been much longer had I asked for /cvs/cds/caltech as well!).

you can view the backups by logging on to garrak.ligo.caltech.edu with your GC account:
/backup/40m/cvs/cds/
/archive/frames/trend/minute-trend/40m

1061

Mon Oct 20 20:50:09 2008

FSS board chip replacement

A quick update.

I changed two AD797s on the FSS board to AD829s to mitigate the 50MHz oscillation, which I plan to report later.
For some reason, the PA85 was broken after the replacement. So I had to replace it with a spare one too.
Right now the FSS is back and working. The oscillation is gone.
However, the maximum achievable gain is still about the same as before.

1065

Tue Oct 21 18:19:42 2008

LISO and Eagle installed

I installed LISO, a circuit simulation software, into the control room linux machines.
I also installed a PCB CAD called Eagle to serve as a graphical editor for LISO.
I put a brief explanation in the wiki.
http://lhocds.ligo-wa.caltech.edu:8000/40m/LISO

As a demonstration, I made a model of the FSS PC path and did a stability analysis of the op-amps.

The first attachment is the schematic of the model.
You can find the model in /cvs/cds/caltech/apps/linux/eagle/projects/liso-examples/FSS

The second attachment shows the stability analysis plot of the first two op-amps when AD829s are used.
The op-amp model is for the uncompensated AD829. The graph includes the bode plots of the open-loop transfer function of each op-amp.
If the phase delay is more than 360deg (in the plot it is 0 deg because the phase is wrapped within +/-180 deg) at the unity gain frequency,
the op-amp is unstable.
It is clear from the plot that this circuit is unstable. This is consistent with what I experienced when I replaced the chips to AD829 without
compensation.
Unfortunately, I don't have an op-amp model for phase compensated AD829. So I can't make a plot with compensation caps.

The third attachment is the stability analysis of the same circuit with AD797. It also shows that the circuit is unstable at 200MHz, though I
observed oscillation at 50MHz.

Finally, I did an estimate of frequency noise contribution from the noise of AD829.
First I estimated the voltage noise at the output of the board caused by the first AD829 using LISO's noise command.
Then I converted it into the input equivalent noise at the stage right after the mixer by calculating the transfer function
of the circuit using LISO.
Within the control bandwidth of the FSS, this input equivalent noise appears at the mixer output with the opposite sign.
Since we know the calibration factor from the mixer output voltage to the frequency noise, we can convert this into the frequency noise.
The final attachment is the estimated contribution of the AD829 to the frequency noise. As expected, it is negligible.

Attachment 1: FSS_PC_Path.pdf

Attachment 2: AD829Stability.png

Attachment 3: AD797Stability.png

Attachment 4: FreqNoiseByAD829.png

1078

Thu Oct 23 20:47:28 2008

FSS LO calibration for MEDM

Today I took a quick series of measurements to calibrate the FSS LO power measurement in the MEDM. This was done by using the spec.an. to measure the 21.5 MHz peak in dBm at the LO input to the FSS box on the PSL table, and recording the MEDM value, for attenuations applied at the FSS REF box output ranging from -5 dBm to -30 dBm.

I measured the loss due to the BNC cable I used, which was (19.66-19.50) dBm. I accounted for this and plotted ln(MEDM) vs. dBm on the attached plot. A linear fit of this gives the CALC field of a calc record for the IOC db:
6.29*LOGE(A)+5.36

Since no one knew how to do this nonlinear conversion in EPICS I will describe how to do it in detail tomorrow. It is simple, although it requires power cycling the scipe3 bunch (typing "reboot" or "ctl-x" at the command prompt took it down, but it did not come back). I did power cycle those computers a few times today.

Attachment 1: fss_lo_calibration.png

1081

Fri Oct 24 10:06:16 2008

MC gain and FSS gain changed

IOO

Following the measurements of MC and FSS loop gains, I modified mcup script to set the MC VCO gain to 2dB (it was -4dB before).
I also changed the normal value of the FSS common gain to 7dB. The open loop transfer functions posted in the previous two entries
were measured with those settings.

1083

Fri Oct 24 11:21:26 2008

FSS LO input calibrated in dBm

Based on the measurements described in my previous elog, I created a new calc record in the file /cvs/cds/caltech/target/c1psl/psl.db

grecord(calc, "C1:PSL-FSS_LOCALC")
{
        field(INPA,"C1:PSL-FSS_LODET")
        field(SCAN,".1 second")
        field(PREC,"4")
        field(CALC,"6.29*LOGE(A)+5.36")
}

After restarting scipe3 to load this change, I told C1PSL_FSS.adl to look at this record instead of *LODET. That MEDM screen now shows LO input calibrated in dBm.

For reference, the operators available for use in the CALC field are listed in the EPICS Record ref manual, Chapter 9. The manual can be found here:
http://www.aps.anl.gov/epics/EpicsDocumentation/AppDevManuals/RecordRef/Recordref-3.html

Yoichi said he was fixing an SVN problem, so I have not yet committed the two files I changed: /cvs/cds/caltech/target/c1psl/psl.db and /cvs/cds/caltech/medm/c1/psl/C1PSL_FSS.adl.

1088

Fri Oct 24 20:54:41 2008

I have removed linux2 and its cables from the control room and put it into 1Y3 along with op340m.

When Joe next comes in we can ask him to Cat6 it to the rest of the world, although it already
seems to me that the CDS hub/switch next Alberto's desk is too full and that we need to purchase
a 48 port device for there.

1089

Fri Oct 24 21:49:15 2008

Jenne

PEM

Short Seismometer Cable

Bad news regarding the cable that goes between the Guralp seismometer and the box that I've been working on: it's too short by about a factor of 2. Dang it. I've placed the seismometer underneath the Beam Splitter Chamber (where it needs to go), and started running the cable toward the ADC rack where box was planned to go, and as Rana guessed earlier tonight, the cable isn't nearly long enough. We have some options: the seismometer can go back into the half-height rack near the BS, SRM, PRM oplev's optical table where I think it used to be, or it can go into the rack with the Kepco high voltage power supplies and the laser's supply. The cable won't reach any farther than that.

I think that we can just add BNC extensions onto the octopus cable that Bob made for the Guralp box, so all we need to figure out after we decide on a rack is the power for the box.

1093

Mon Oct 27 11:16:23 2008

I implemented the calibration for the four channels of the StochMon in the ioo EPICS database. Now the output of those channels, as shown in the medm screen, gives the peak-to-peak amplitude in voltage of each frequency from the RFAMPD at the transmission of the MC, normalized by the DC output from the same photodiode.

Basically the calibration takes into account the following factors:
- two in series RF preamplifiers, currently laying on the PSL table near the RFAMPD, with gains of 19 dB and 17 dB, respectively
and, inside the StochMon blue box:
- a resonant band-pass filter with the following gains h_f(f) for each of the frequencies of interest: 33MHz -39.5 dB; 133MHz -40.8 dB; 166MHz -49.0 dB; 199MHz -45.0 dB
- a power detector that provides an output voltage linearly proportional to the input power in dBm, with a factor alpha of proportionality equal to an average value of -0.0271 V/dBm for all the frequencies

The calibration that relates the output voltage from the PD to the output voltage from the StochMon is then obtained as:

V_pd(f) = sqrt(2*R*P0)/h_f(f) * 10^( (Vo-q)/(20*alpha) )

where R=50ohm, P0=1mW and q=0.772 V, the latest being the offset in the calibration of the power detector (that is its output for a 0 dBm input).

1095

Mon Oct 27 14:48:27 2008

EO shutter installed to the reference cavity

I'm now preparing for cavity ring down measurements of the reference cavity.
An EOM for polarization rotation is installed between the two steering mirrors for the reference cavity.
The location is before the polarized beam splitter (used to pick-up the reflected light from the cavity) and
after the half-wave plate. So we should be able to use the PBS as a polarizer.
While setting up the high voltage pulse generator, I realized that we don't have enough cables for it.
It uses special kind of connectors (Kings 1065-N) for HV connections. We need three of those but I could find
only two. I asked Bob to order a new connector.

For the moment, the EOM is left in the beam path of the reference cavity until the connectors arrive (Wed. or Thu. this week)
and the measurements are done.
The EOM distorts the beam and degrades the mode matching to the reference cavity.
I optimized the alignment of the crystal so that the RC transmission is maximum.
Even though, the transmission of the reference cavity is down from 2.8 (without EOM) to 1.7 (with EOM).
I increased the common gain of the FSS from 7dB to 10dB to compensate for this.
The mode clearner locks with this configuration.

If the EOM is really disturbing, one can just take it out.
Since I did not touch the steering mirrors, the alignment to the reference cavity should be recovered immediately.

1098

Tue Oct 28 12:01:01 2008

Quote:

Note I still need to remove a fair bit of cabling no longer in use from the Martian network switch next to Alberto's desk. There's actually about 8-10 cables there which show no connectivity and are not being used. So there's really about 33% of the ports open in the control room hub, it just doesn't look like it.

As for linux2, I'll probably just connect it to the 1Y2 or 1Y6 Hubs when I get the chance.

1099

Wed Oct 29 12:23:04 2008

MZ alignment touched and the alarm level changed

Since the MZ reflection is alarming all the time, I tried to improve the MZ alignment by touching the folding mirror.
I locked the X-arm and monitored the transmitted light power while tweaking the mirror alignment to ensure that the output beam pointing is not changed.
I changed the alignment only a little, almost like just touching the knob.
The reflected power monitor was around 0.6 this morning and now it is about 0.525. Still large.
I changed the alarm level (HIGH) from 0.5 to 0.55.

1102

Thu Oct 30 20:39:47 2008

We attached the temperature sensor box to the MC1/MC3 chamber with a C-clamp. We connected the temp sensor to a 2nd box with a short BNC. Bob set up a power cable coming from the X-end towards the MC1/MC3 chamber(Thanks, Bob!) We soldered the end of Bob's power cable to a plug and attached it to the 2nd box (The power supply enters through the 2nd box). A ~20ft BNC cable connects the output signal of the 2nd box to the tall thing by the PSL where all the signals go labeled 1Y2. Once we had everything connected, we put in the fuses for the power supply. So, now the temperature sensor is receiving power. We checked that the power supply was working (we measured +15.08V and -14.95V, and we wanted 15V and -15V so it's OK for now). Tomorrow we will modify C1IOOF.INI file and reboot the frame builder.

About sensor-
There is an LM34 (looks like a transistor) glued w/ epoxy and thermal paste to the inside of a Pomona box ~1"x"1.5"x2". The lid to the box is covered with a 1-2mm thick piece of copper and a little thermal paste is sandwiched between the Pomona lid and the copper piece. A C-clamp attaches the copper piece to the chamber. A BNC is connected to one side of the box (the side with less copper)

About power supply box-
There is a power regulator and an op-amp inside a Pomona box ~2.5"x4"x2". The power regulator is attached to the center of lid of the pomona box with a screw and washer. There's a power plug on the front of the box
Left:+15V:red wire
Center:GND:white wire
Right:-15V:black wire
There are 2 BNC connections on the sides of the box. The left BNC connection is for the output signal and the right BNC connection is for the temperature sensor (if the power plug is coming out of the box towards you).

Sensor location-
Chamber which contains MC1/MC3. On the door facing towards the Y-end. On the bottom-left side. Behind the door. Attached with a C-clamp.

Power supply box location-
Chamber which contains MC1/MC3. On some metal leg thing near the floor facing towards the Y-end. Attached with a zip-tie

Power supply-
Coming from the X-end from a tall thing with all the fuses labeled 1X1
Fuse 160:+15V:red wire
Fuse 171:GND:white wire
Fuse 172:-15V:black wire

Signal-
Going towards the PSL to the tall thing labeled 1Y1 on the rack labeled SN208
ICS-110B
J12 (which we believe corresponds to 50-51 and channel number 13650)
Temperature sensor is connected to J12 with a ~20ft BNC attached to a BNC2LEMO connector we found lying around

1104

Sun Nov 2 20:21:58 2008

HP 5550dtn (Grazia) set up on allegra

lore

I set up printing to grazia from allegra. The CUPS interface was not as straightforward as Tobin had made it seem in the Wiki. I had to type in the IP address and port number by hand.

The steps (AFAIR):

1) Goto http://localhost:631/
2) Click on "Add Printer"
3) Choose HP JetDirect
4) Use the correct address (socket://131.215.115.220:9100)
5) Choose HP and the 5550 postscript driver as the options
6) Try to only print useful stuff and not kill too many trees.

1109

Mon Nov 3 19:18:47 2008

Phil Ehrens kindly poured our elog's content in a CD that now is here at the 40m.
I've been trying to install the 2.7.5 version of the elog on Nodus, a Sun machine, but the installing procedure is different from linux and I dont' know it. I tried to recompile the elog from the source code but the way gcc is called must be wrong because I get this error message:

nodus:elog-2.7.5>make
gcc -DHAVE_SSL -o elog src/elog.c -lsocket -lnsl -lssl
src/elog.c:45:25: openssl/ssl.h: No such file or directory
src/elog.c:329: error: parse error before "SSL"
src/elog.c: In function `ssl_connect':
src/elog.c:331: error: `SSL_METHOD' undeclared (first use in this function)
src/elog.c:331: error: (Each undeclared identifier is reported only once
src/elog.c:331: error: for each function it appears in.)
src/elog.c:331: error: `meth' undeclared (first use in this function)
src/elog.c:332: error: `SSL_CTX' undeclared (first use in this function)
src/elog.c:332: error: `ctx' undeclared (first use in this function)
src/elog.c:340: error: `ssl_con' undeclared (first use in this function)
src/elog.c:341: error: `sock' undeclared (first use in this function)
src/elog.c: In function `retrieve_elog':
src/elog.c:383: error: `SSL' undeclared (first use in this function)
src/elog.c:383: error: `ssl_con' undeclared (first use in this function)
src/elog.c: In function `submit_elog':
src/elog.c:631: error: `SSL' undeclared (first use in this function)
src/elog.c:631: error: `ssl_con' undeclared (first use in this function)
make: *** [elog] Error 1

Joe, Yoichi, anyone else knows how to do that?

1110

Mon Nov 3 21:38:32 2008

Quote:

I tried to recompile the elog from the source code but the way gcc is called must be wrong because I get this error message:

nodus:elog-2.7.5>make
gcc -DHAVE_SSL -o elog src/elog.c -lsocket -lnsl -lssl
src/elog.c:45:25: openssl/ssl.h: No such file or directory
src/elog.c:329: error: parse error before "SSL"

The location of ssl.h is a bit strange in the sunfreeware version of OpenSSL. Since elog does not use configure script, you have to
edit Makefile and add an appropriate -I option to an appropriate variable definition (probably LIBS or CFLAGS, because the elog Makefile does
not use INCLUDES).
If you don't understand what I'm saying, just wait for me.

1119

Thu Nov 6 22:07:56 2008

ELOG compile on Solaris

From the ELOG web pages:

Solaris:

Martin Huber reports that under Solaris 7 the following command line is needed to compile elog:

gcc -L/usr/lib/ -ldl -lresolv -lm -ldl -lnsl -lsocket elogd.c -o elogd

With some combinations of Solaris servers and client-side browsers there have also been problems with ELOG's keep-alive feature. In such a case you need to add the "-k" flag to the elogd command line to turn keep-alives off.

1133

Thu Nov 13 15:50:44 2008

The schematic of the 1Y7 rack that Alan pointed out (see attachment) don't represent anymore the actual rack.
First, with Yoichi we found that the GPS receiver for the 10 MHz is in a different position,
on the other side of the VME computer. It seems to output 1 kHz, which also appears in some modulated way.
This signal is then passed to a board on 1Y7 that seems make just copies of the signal. One of these goes
to an other board in 1Y6 that looks like a GPS receiver but has actually no GPs antenna input. Here it is
not connected to anything, but on its same crate is a the awg computer, so it might be providing the clock
to that by the crate.

We also checked the clock monitor output on the boards in the PSL that provides for the clock to the Penteks
and it seems that these are actually getting 4MHz.

Attachment 1: rackstuff.pdf

1146

Wed Nov 19 10:32:11 2008

Alberto

All the Marconi Set to the Rubidium Frequency Standard

Electronics

I placed the SRS Rubidium FS275 over the PSL rack, next to the frequency counter. This one and the Marconi on the PSL rack have been connected to the 10MHz output of the frequency standard. I set also the first Marconi, the one that used to drive the others, to external, direct frequency reference. Now it reads 166981718 Hz versus 166981725 Hz measured by the frequency counter: 8 Hz difference.

1147

Wed Nov 19 18:02:18 2008