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ID Date Author Type Category Subject
  618   Tue Jul 1 21:45:48 2008 JohnUpdatePSLMach Zehnder script and screen
I've edited C1: PSL_MACH_ZEHNDER.adl and /cvs/cds/caltech/scripts/PSL/MZ/lockMZ
to reflect the changes described in entry #616.
  617   Tue Jul 1 21:27:27 2008 robHowToComputer Scripts / Programsslider twiddling after reboot

Sometimes after we reboot the front-end machines, some of the hardware gets stuck in an unknown state. We generally fix this by twiddling EPICS settings, which refresh the hardware somehow and put it into a known state. I've started a script (slider_twiddle) which we can just run after reboots to do this for us. Right now it just has the QPD whitening gain settings. As we find more stuff, we can add to it. It's in $SCRIPTS/Admin/.
  616   Tue Jul 1 16:48:42 2008 rob, johnConfigurationPSLMZ servo switch problem resolved forever

Quote:
C1:PSL-MZ_BLANK switch (to turn on/off the servo) is not working again. The switch is always off regardless of the epics state.
I pushed the cables into the xycom card, but it did not fix the problem.


We have fixed this problem forever, by totally disabling this switch. Looking at the schematic for the MZ servo and the datasheet of the AD602, we found that a HI TTL on pin 4 disables the output of the AD602. Since the MZ servo was stuck in the off position, this seemed to indicate that it may be the XYCOM220 itself which is broken, constantly putting out a +5V signal regardless of the EPICS controls. We thought we might be able to get around this by disconnecting this signal at the cross-connect, but ultimately we couldn't find it because there is no wiring diagram for the Mach-Zehnder (!). So, we pulled the board and wired pin 9A of P1 to ground, permanently NORMALizing the MZ_BLANK switch. John has marked up the schematic, and someone should modify the MEDM screen and check the new screen into svn.

We can still the turn the MZ servo on and off by using the test input 1 switch.

Someone also will need to modify the MZ autolocker to use the test input 1 (MZ_SW1) instead of the old MZ_BLANK.
  615   Tue Jul 1 14:24:58 2008 robHowToComputer Scripts / Programsconlog time machine

I've written a perl script (now in the $SCRIPTS/general directory) which implements a "conlog restore" command, restoring channels matching a regexp to a given time using the conlog records and the EpicsTools.pm perl module. The script is called time_machine_conlog:


Quote:


op440m:~>time_machine_conlog

time_machine_conlog restores EPICS control settings using a conlog time
usage: time_machine_conlog [<--dryrun>] <date=yyyy/mm/dd,hh:mm:ss> <timezone> <regexp>

Can also accept a gps time, in which case timezone=gps.
Use the option <--dryrun> to see conlog output without restoring any settings.

EXAMPLE: time_machine_conlog 2008/05/30,12:00:00 PDT "C1:SUS-MC.*_(PIT|YAW)_COMM"



It sometimes returns an error message even when the command is successful--this is because conlog stores EPICS settings to an absurd level of precision, but ezcawrite will not write EPICS values to this level (or at least won't indicate if it did). I consider this a bug in ezcawrite so I'm not touching it.

The script is untested with regards to switch settings (such as ENABLE/DISABLE). It's mainly intended for numerical values.
  614   Tue Jul 1 13:34:29 2008 robUpdateComputersRFM network back

Quote:

For some reason, the computers requiring startup.cmd (like c1lsc) halt after running this command. Actually the computer is running ok, but the command freezes. Basically, what it does is simply to load a kernel module. I don't know what is wrong.
Anyway, I just closed the terminal after running startup.cmd and it seems fine for now.


This is normal. On the linux RTFEs (Real-Time Front Ends), the real-time code totally hijacks the kernel, disallowing any interrupts. The system thus becomes totally unresponsive while the code is running, and communicates only through the RFM and the VME backplane.
  613   Tue Jul 1 12:51:34 2008 JohnSummaryGeneralIFO alignment
Rana, Rob, Yoichi, John

The recent computer problems and MZ work had disturbed the alignment of the interferometer.

We adjusted the MC alignment back to nominal positions using old OSEM values. We then walked
the input beam to match the MC. Coupling into the interferometer has increased noticeably.
The rest of the IFO was then aligned to the new input beam.

Proceeding to full IFO locking we were able to engage the AO path and hand off CARM to SPOBDC.
Arm powers got up to 4.

If the new alignment proves successful we will centre all QPDs etc so we can easily return to
this state.
Attachment 1: align080701.png
align080701.png
  612   Tue Jul 1 12:08:38 2008 John, JoeConfigurationPSLPMC input PD
Joe and I switched cables so that the PMCR screen actually shows reflection not transmission.

The trans camera had a BNC connected to "video out" labelled PMC input PD. The video signal
going to the monitors does not come from "video out", it comes out the "DC in/sync" cable.
As far as we can see this diode doesn't exist. Where should the PMC input PD BNC cable be
connected?
  611   Tue Jul 1 11:57:24 2008 YoichiConfigurationPSLMZ servo switch problem again
C1:PSL-MZ_BLANK switch (to turn on/off the servo) is not working again. The switch is always off regardless of the epics state.
I pushed the cables into the xycom card, but it did not fix the problem.
  610   Tue Jul 1 11:53:38 2008 YoichiUpdateComputersRFM network back
I took a tour of the FE machines and power cycled all of them.
After executing the software restart procedures of those computers, the RFM network got back to the normal state.
For some reason, the computers requiring startup.cmd (like c1lsc) halt after running this command. Actually the computer is running ok, but the command freezes. Basically, what it does is simply to load a kernel module. I don't know what is wrong.
Anyway, I just closed the terminal after running startup.cmd and it seems fine for now.
  609   Tue Jul 1 10:15:22 2008 steveUpdatePSLeventfull two days
The laser recovered from a short temp rise. The MZ was aligned and realigned. The suspentions were kicked up accidentally.
Now the computers are down.
Attachment 1: 2d.jpg
2d.jpg
  608   Tue Jul 1 09:26:33 2008 steveUpdateComputersRFM network is down
  607   Mon Jun 30 18:36:01 2008 YoichiUpdatePSLMZ alignment again
John, Yoichi

We re-adjusted the MZ alignment. The reason behind this is to make sure that the MZ dark port is not falling at a strange fringe, where it is only dark at the dark port PD. It can happen when the two beams poorly overlap.
We tried both the minimization of the MZ dark PD and the maximization of the MZ transmission at the same time.
We also placed another PD in the MZ dark port at a different distance from the original dark PD and tried to minimize this too.
If the MZ dark port is at a strange fringe, one of the dark PD can be dark where the other one is still bright.
If both of the dark PD get dark, the overlap between the beams should be ok.
We tweaked only the two mirrors of the MZ after the EOMs (mainly the one with a PZT).

Right now, the MZ dark power is 0.432.
BTW, we should change the name of the MZ dark port on the medm screen (it is now MZ reflection, where it is not a reflection).
I will try to change it later.

We wanted to put the beam position on the IOO-QPD_POS_* back to the original (before John tweaked the MZ alignment earlier).
However, the trends of IOO-QPD_POS_* show a lot of fluctuation and jumps, of which we don't know the cause. So we could not find reasonable original values.
We suspect a circuit problem in IOO-QPD_POS, especially because the jumps are very strange.
We will do this investigation later too.
  606   Mon Jun 30 16:00:02 2008 josephb, samConfigurationComputers 
Sam and I setup Cat6 cable from Megatron to the 1Y6 Switch (131.215.113.252) and also connected the 1Y6 Hub to the control room switch.

While I was at it, I checked the configurations of the two switchs now connected (one in 1X4 and one in 1Y6) to the martian network. For some reason, the 1X4 had switched to DHCP enabled and was using 131.215.113.105 as an IP address. I had thought I had setup it correctly initially, so am not sure what caused the change.

The easiest way I know of to check the setup is use smartwizard discovery program from the Netgear install CD (in the equipment manual file cabinet of the control room) on a windows machine. The passwords have been set to the controls password.

Megatron should now see and be accessible through the martian network.
  605   Mon Jun 30 15:56:22 2008 JenneUpdateElectronicsFixing the LO demod signal
To make the alarm handler happy, at Rana and John's suggestion I replaced R14 of the MC's Demod board, changing it from 4.99 Ohms to 4.99 kOhms. This increased the gain of the LO portion of the demod board by a factor of 10. Sharon and I have remeasured the table of LO input to the demod board, and the output on the C1:IOO-MC_DEMOD_LO channel:

Input Amplitude to LO input on demod board [dBm]: | Value of channel C1:IOO-MC_DEMOD_LO
------------------------------------------------- | -----------------------------------
-10 | -0.00449867
-8 | 0.000384331
-6 | 0.0101503
-4 | 0.0296823
-2 | 0.0882783
0 | 0.2543
2 | 0.542397
4 | 0.962335
6 | 1.65572
8 | 2.34911
10 | 2.96925
  604   Mon Jun 30 15:08:52 2008 JohnSummaryPSLMZ alignment
I adjusted the alignmnet of the Mach-Zehnder's two North mirrors (downstream of the EOMs).

MZ REFL is reduced from 0.54 to 0.43. The largest improvement was due to pitch on the PZT mirror.
Attachment 1: mzalign.png
mzalign.png
  603   Mon Jun 30 14:07:26 2008 RobConfigurationPSLDon't put the bin in front of the air conditioning unit

Quote:
We spotted that the laser power was dropping.


the offending configuration:
Attachment 1: DSC_0140.png
DSC_0140.png
  602   Mon Jun 30 13:48:47 2008 John, RobConfigurationPSLDon't put the bin in front of the air conditioning unit
We spotted that the laser power was dropping.

The air conditioning unit was blocked by the blue bin/trash can/cestino causing the laser head temp to increase by 2 degrees.

Let's be careful about this in the future.
Attachment 1: binremoval.png
binremoval.png
  601   Mon Jun 30 09:46:15 2008 JohnUpdateIOOMC WFS
MC WFS are on. They seem to do some good during the day.
  600   Mon Jun 30 08:59:23 2008 steveUpdateIOOIOO-MC_DEMOD_LO is low
The alarm handler is beeping relentlessly: asking for help in high partical count and low demod signal
Attachment 1: demlo.jpg_____
demlo.jpg_____
  599   Mon Jun 30 05:33:38 2008 KojiUpdateGeneralAbs. Len. Meas. ~ Optical setup (II)
o The position of the iris was adjusted so as not to disturub the beam for OMCR CCD.

o The RF spectrum analyzer was returned to the place of the network analyzer.


Quote:

In the process of making this report, I noticed that one of the iris apertures is about disturbing the beam for OMCR CCD. I will check this before I go to Hanford. Also an RF spectrum analyzer is at the AP table. I try to return this near the PSL on Monday morning.
  598   Mon Jun 30 01:49:06 2008 JohnUpdateIOOMC work
I'm in the process of aligning the mode cleaner/ input beam.

I turned off the WFS and cleared their histories, adjusted the input periscope and re-aligned the mode-cleaner accordingly.
I then unlocked the cavity and centred the beams on the WFS.

MC transmission is ~3.3 and the REFL beam looks a little better.

However, turning the WFS on now lowers the transmission. More thought tomorrow.

I'm leaving the MC locked with WFS off.
  597   Sun Jun 29 20:29:48 2008 ranaUpdatePSLCorrelation of PSL SLOW control v. Room temperature
Attachment 1: slowtemp.png
slowtemp.png
  596   Sun Jun 29 20:09:40 2008 JohnSummaryIOOmcup and mcdown indicators
I edited the mcup and mcdown scripts so that C1IFO_STATE shows when these scripts are running.

I also added indicators to the LockMC screen.
Attachment 1: mcscreen.png
mcscreen.png
Attachment 2: ifostate.png
ifostate.png
  595   Sun Jun 29 19:53:26 2008 JohnSummaryPSLISS

Quote:
I reduced the gain of the ISS (C1: PSL-ISS_VGAGAIN) from 5dB to 2dB. Any higher and it constantly saturates.


Seemed to go back to normal after the frame builder came back.
  594   Sun Jun 29 19:19:47 2008 ranaSummaryIOOTrends of the PSL/IOO Quads over 1000 days
Only IOO POS has been working for the past 2 years. I guess we should recommission the IOO ANG and REFL QPDs
Attachment 1: a.png
a.png
  593   Sun Jun 29 18:58:43 2008 ranaSummaryComputers1e20 is too big for AWG and/or IOVME
While testing out my matlab/awgstream based McWFS diagnostic script I accidentally put a
huge excitation into
C1:IOO-WFS1_PIT_EXC
. This went to 1e20 and then caused
some SUS to trip and c1susvme2 to go red. I tried booting it via the normal procedures
but it wouldn't come back, even after 2 crate power cycles. I also tried booting AWG
via the vmeBusReset, but that didn't do it. Then I booted c1iovme from the telnet prompt
and then I could restart c1susvme2 successfully.

The reason the excitation was so large is that the following filter command is unstable:
[b,a] = butter(4,[0.02 30]/1024);

The low pass part is OK, but it looks like making such a low frequency digital filter
is not. Que lastima. On the bright side, the code now has some excitation amplitude
checking.
  592   Sun Jun 29 14:53:02 2008 robUpdateComputersRebooting

Quote:
All of the computers are now showing green lights.

Remaining problems:

Alignment scripts are failing with "ERROR: LDS - NDS server error #13"
I think this is a server transmission error.

Dataviwer shows all channels as zero.


Fixed. Just started the testpoint manager on fb40m.


su
/usr/controls/tpman &
  591   Sun Jun 29 11:31:52 2008 JohnSummaryPSLISS
I reduced the gain of the ISS (C1: PSL-ISS_VGAGAIN) from 5dB to 2dB. Any higher and it constantly saturates.
  590   Sun Jun 29 02:33:28 2008 KojiUpdateGeneralAbs. Len. Meas. ~ Optical setup (I)
I have constructed the beam injection optics for the abs length measurement.

The injection beam was coarsely aligned to the interferometer. The reflected beam from SRM was already seen at AS CCD.
I have attached the optical configration for this measurement and the optics layout at the AP table.

I am going to go to LHO for three weeks. During the absence Alberto tunes the mode matching and the alignment of the interferometer.

In the process of making this report, I noticed that one of the iris apertures is about disturbing the beam for OMCR CCD. I will check this before I go to Hanford. Also an RF spectrum analyzer is at the AP table. I try to return this near the PSL on Monday morning.

Attachment 1: Optical configuration for the abs length measurement.
1) One of the arms is locked to the PSL beam by the main control system (red).
2) A laser beam is injected from the AS port (blue). This laser essentially has different frequency from that of PSL.
3) The injected beam and the outgoing PSL beam appear at the output of the faraday in the injection system.
4) They beat each other at the frequency difference of those two lasers.
5) A PLL is used to lock the frequency difference to a local oscillator (LO).
6) The LO frequency is swept at around 3.87MHz, that is the approximate FSR frequency of the arm cavity.
7) If the LO frequency hits the FSR within the resonant width, the beating also appears at the transmitted light as the injected beam also becomes resonant to the arm cavity.
8) Amplitude of the beating at the transmitted light is measured by a RF spectrum analyzer as a function of the LO frequency. We get the FSR frequency (= the arm cavity length) from the top of the resonance.

Attachment 2: Optics at the AP table for the laser injection
700mW NPRO, laser source. vertically polarized.
Periscope, to raise the beam 1 inch to make the beam at the 4 inch elevation.
INJ_SM1/INJ_SM2, steering mirrors to align the injection beam to the IFO beam.
HWP1, half wave plate to make the beam to the farady horiz-polarized. nominal 42deg on the readout.
FI, Faraday isolator for protection of the NPRO from the returning light, for obtaining the returning light.
HWP2, to make the beam from the Faraday horiz-polarized. nominal 357deg on the readout.
MM_Lens, f=125mm to match the laser mode to the IFO beam.
SM1/SM2, steering mirrors to align the IFO beam to the Farady Isolator.
IRIS1/IRIS2, for the coarse alignment of the injection beam.
FLIP, flipper mount to turn on/off the injection optics.

Alignment procedure of the injection system
0) Ignite NPRO several hours before the experiment so that the laser frequency can be stable.
1) Turn up FLIP. Close the shutter of NPRO.
2) Adjust SM1/SM2 so that the ifo beam can appear at the output of FI.
3) Adjust height and position of IRIS1/IRIS2 with regard to the ifo beam so that the ifo beam goes through IRIS1/IRIS2 even when they are closed.
4) Turn down FLIP. Open the shutter of NPRO.
5) Adjust INJ_SM1/INJ_SM2 so that the injection beam can go through IRIS1/IRIS2 even when they are closed.
6) At this time, it is expected that the reflection of the injection beam from SRM appears at AS CCD, if SRM is aligned.
7) Adjust INJ_SM1/INJ_SM2 so that the injection beam at AS CCD can overlap to the IFO beam.
8) Confirm the beam at the output of the FI also overlaps.
---- We are here ----
9) Change the ifo configuration to the X or Y arm only.
10) Scan the crystal temperature of the 700mW NPRO in order to try to have the beating of the two beams at the PD. AS OSA may be useful to obtain the beating.
11) Once the beating is obtained, adjust INJ_SM1/INJ_SM2 such that the beating amplitude is maximized.
Attachment 1: optical_configuration.png
optical_configuration.png
Attachment 2: optical_layout_ap_table2.png
optical_layout_ap_table2.png
Attachment 3: optical_layout_ap_table2.pdf
optical_layout_ap_table2.pdf
  589   Sat Jun 28 23:23:50 2008 JohnUpdateComputersRebooting
All of the computers are now showing green lights.

Remaining problems:

Alignment scripts are failing with "ERROR: LDS - NDS server error #13"
I think this is a server transmission error.

Dataviwer shows all channels as zero.
  588   Sat Jun 28 14:56:44 2008 JohnUpdateComputersini files
In short, I was editing the ini files yesterday evening, I didn't e-log it and after some investigation this afternoon it apears
that I am to blame for all the computer problems which followed.


I wanted to edit C0EDCU.ini and C1IOOF.ini to change C1: PSL-FSS_FAST to a fast channel as C1: PSL-FSS_FAST_F
was dead.

I opened these files and made backups. It appears this is where it all went awry. My backup for C1IOOF
is called C1IOO.ini.090627 i.e. missing the F.

Later c1susvme2 and c1iovme crashed. After failing to bring c1iovme back I wondered if my edits had
caused the problems so I restored the back up files. It appears that here I wrote over C1IOO with my backup of
C1IOOF (presumably because I had made a typo in the name).

To remedy the situation we could restore C1IOO from e.g. chans/archive/C1IOO_080618_160028.ini

No excuses for not e-logging this activity.
  587   Sat Jun 28 03:10:25 2008 robUpdateComputersc1iovme

Quote:
C1susvme2 and C1iovme crashed which sent the optics swinging and tripped the watchdogs.

Koji and I were able to restore c1susvme2 without any trouble.

We have been unable to revive c1iovme. We have tried telneting in and running startup.cmd,
the process runs for a while then hangs with "DAQ init failed -- exiting".

Resetting the board doesn't help. I didn't try keying the whole crate.

All optics are back to normal with damping restored.


I tried keying the crate, then keying the DAQ controller & AWG, then powering down & restarting the framebuilder.
On coming up, the framebuild doesn't start a daqd process, and I can't get one to start by hand (it just prints "652", and then stops).
No error messages and daqd doesn't appear in the prstat.

I then tried keying the DAQ controller again (after the fb0 reboot), which blew the watchdogs on all the suspensions. So then I went around and keyed all the crates.

Now, the suspension controllers are back online. Still no c1iovme, and now the framebuilder/DAQ/AWG are also hosed. We can try keying all the crates again, in the order that Yoichi did last week.

After some more poking around, I found the daqd log file. It's now complaining about

Jun 28 03:00:39 fb daqd[546]: [ID 355684 user.info] Fatal error: channel `C1: PSL-FSS_MIXERM_F' is duplicated 126

This is the second error message like this. It first complained about C1: PSL-FSS_FAST_F, so I commented that out of C1IOOF.ini and rebooted the framebuilder (note this is an actual reboot of the full solaris machine). Eventually I discovered that C1IOOF.ini and C1IOO.ini are essentially identical. They presumably will keep getting these duplicate channel errors until one of them is completely removed.

C1IOO.ini has a modification time of seven PM on Friday night. Who did this and didn't elog it? I've now modified C1IOOF.ini, and I don't remember when it was last modified.
  586   Fri Jun 27 19:59:44 2008 JohnUpdateComputersc1iovme
C1susvme2 and C1iovme crashed which sent the optics swinging and tripped the watchdogs.

Koji and I were able to restore c1susvme2 without any trouble.

We have been unable to revive c1iovme. We have tried telneting in and running startup.cmd,
the process runs for a while then hangs with "DAQ init failed -- exiting".

Resetting the board doesn't help. I didn't try keying the whole crate.

All optics are back to normal with damping restored.
  585   Fri Jun 27 18:21:01 2008 JenneUpdateElectronicsResponse of the LO input on the MC demod board
The alarm handler has been flipping out saying that the LO input of the MC's demod board is too low, so at Rana's suggestion, Eric and I measured the response of the LO input. We used an SR345 function generator at 29.485MHz and several different amplitudes to make a table. The demod board should see an input from the LO between 0-2dBm. When I measured what was going into the LO input from the 29.5MHz delay line phase shifter, the LO input was seeing 4dBm. I'm going to put a 3dB attenuator between the phase shifter and the demod board.

Also, now that we have this table of response values, I'm going to change the settings of the alarm handler to something more reasonable.
Amplitude of 29.485MHz input sine wave [dBm]    |        Value of channel C1:IOO-MC_DEMOD_LO
--------------------------------------------    |        -----------------------------------
-10                                             |        -0.000449867
-8                                              |        -0.000449867
-6                                              |        -0.000449867
-4                                              |        0.000384331
-2                                              |        0.00526733
0                                               |        0.0199163
2                                               |        0.0492143
4                                               |        0.0931613
6                                               |        0.161523
8                                               |        0.229885
10                                              |        0.293364
  584   Fri Jun 27 18:03:46 2008 JenneUpdateElectronicsAnother bad cable in the MC servo
Eric was helping me to measure the response of the LO input on the MC's Demod board, and when we disconnected the end of the cable between the demod board and the delay line phase shifter for the 29.5MHz oscillator, we noticed that the phase shifter's end of the cable was loose, like the connector wasn't fully connected. When we checked it by wiggling the connector, the SMA end fell off. I made a new SMA end for the cable, and reinstalled the cable. The MC locked as soon as I plugged the cable in, so everything seems good again. I tried to not change the cable length when I remade the connector, but the cable is shorter than it was by a small amount, due to the way the end fell off.
  583   Fri Jun 27 15:20:52 2008 robDAQLSC.ini file change

I removed C1:LSC-XARM_CTRL from the frames and added C1:LSC-CARM_ERR
  582   Fri Jun 27 14:36:39 2008 JohnSummaryLocking 
Rob, Yoichi, John

Some progress last night:

Switched back to SPOB_DC for CARM.

Shaped the MC LSC loop to reduce excess noise in the 20-30Hz band. Likely the most significant change.
Could this be due to fan noise from the laptop on the SPOB table?

Brought in the AO path earlier (at low gain).

Reduced offset to 6 and increased MC gain before handing off to SPOB. Ramped up AO and MC gain then switched off the
moving zero.

Looks like PD11 is the most promising candidate for RF CARM although the demod phase needs attention.
Attachment 1: gettingcloser.png
gettingcloser.png
  581   Fri Jun 27 09:20:15 2008 steveFrogsPEMdust particle count is up & alarm handler is on
This 3 years plot show the trend of seasons.
When outside air quality goes bad ( 0.5 micron > 1 million ) the lab follows.
I will demonstrate this effect with a 4th of July fire works calibration.
Let's do not forget the construction activity next door either.

The alarm handler is busy:
It's sound level were reset to a modest level yesterday.
It would be nice to change the alarm sound so it can play Wagner:Der Ring des Nibelungen:
Das Rheingold, Die Walkure & Siegfried and Gotterdammerung
or something more appropriate than the present frog call

1, half micron count is climbing ( it's close to 16k now )
2, MZ refl signal is too high
3, MC lenght servo LO is too
Attachment 1: dust3y.jpg
dust3y.jpg
  580   Thu Jun 26 22:08:33 2008 JenneUpdateElectronics3.7MHz bandstop filter in MC Servo
The 3.7MHz elliptical bandstop filter that I made during my SURF summer is now installed in the MC servo loop to reduce the noise at 3.7MHz.

I have taken transfer functions with and without the filter between TP1A and TP2A, with EXCA at -20dBm, using the HP4195A Network Analyzer. I have also taken power spectra of TP1A with and without the filter, and time domain data with the filter of OUT2 on the MC Servo Board and Qmon on the Demod board just before the MC servo board. The filter is between Qmon and OUT2 in the loop.

The UGF and phase margin don't change noticeably with and without the filter, and the MC still locks nicely (after the minor fiasco this afternoon), so I think it's okay. The UGF is around 57kHz, with about 38 degrees phase margin.

1 July 2008: I redid the plots. Same info, but the traces with and without the filters are now on the same graph for easier readability.
Attachment 1: MCLoopGainBoth.png
MCLoopGainBoth.png
Attachment 2: TP1ASpectrumBoth.png
TP1ASpectrumBoth.png
Attachment 3: QmonWithFilt.png
QmonWithFilt.png
Attachment 4: MCOut2WithFilt.png
MCOut2WithFilt.png
  579   Thu Jun 26 21:07:11 2008 ranaConfigurationASSdust & MC1
I realized today, that yesterday while we were trying to debug the adaptive noise canceler, I turned
off the analog dewhitening on MC1. I did this by changing settings on the Xycom screen but I
forgot to elog this -- this may have caused problems with locking via increased frequency noise.
I have now returned it to its nominal, dewhitening on, configuration.

I also used mDV to look at the last year of dust trend. I have plotted here the cumulative
histogram in percentile units of the 0.5 micron dust level. The x-axis is in units of particles per cu. ft.
and the y-axis is percentage. For example, the plot tells us that over the last year, the counts were
below 6000, 90% of the time. I have set the yellow and red alarm levels to alarm at the 95-th and 99-th
percentile levels, respectively.
Attachment 1: Screenshot-2.png
Screenshot-2.png
  578   Thu Jun 26 20:59:22 2008 ranaUpdateComputer Scripts / ProgramsAlarm Handler
Please do not turn off the Alarm Handler on op540m.
  577   Thu Jun 26 18:29:44 2008 JenneUpdate MC Back online
Jenne, Rob, Yoichi

I was playing with the Mode Cleaner earlier today, working on measuring the effect of the new filter (see next post for loop gain measurements etc.), and bumped something which made it so the Mode Cleaner would not lock.

After much poking around by Rob and Yoichi, we found that the TNC-to-2 pin LEMO from Out1 of the MC Servo Board to Ch1 of the Pentek Generic board to the right of the MC Servo Board was bad. If we touched the cable, the MC would lock, but as soon as we let go, the MC would fall out of lock. The LEMO end of the cable was not heat shrink wrapped, so the 2 wires could have been touching. I replaced the cable, and the MC locked immediately after plugging it in, so I think that has fixed the problem.
  576   Thu Jun 26 18:27:04 2008 ranaUpdateComputer Scripts / ProgramsNo Dataviewer No Cry
Dataviewer was hanging. It would open the Grace window but then not plot anything. Since DTT was working
fine we diagnosed this as a DV only problem. It turned out that there was a boatload of messages in the
dataviewer queue. You can check for extra messaages using the command 'ipcs -q' and then use 'rmq' to remove them.

Dataviewer is working now.

Here's the screen dump from op440m:
op440m:~>ipcs -q
IPC status from <running system> as of Thu Jun 26 18:19:32 PDT 2008
T         ID      KEY        MODE        OWNER    GROUP
Message Queues:
q        400   0x1a51     -Rrw-rw-rw- controls    staff
q          1   0x501      -Rrw-rw-rw- controls    staff
q          2   0x512      -Rrw-rw-rw- controls    staff
q        103   0x553      -Rrw-rw-rw- controls    staff
q          4   0x574      -Rrw-rw-rw- controls    staff
q          5   0x18be     --rw-rw-rw- controls    staff
q         56   0x1d9f     -Rrw-rw-rw- controls    staff
q          7   0x1e56     -Rrw-rw-rw- controls    staff
q          8   0x1efd     -Rrw-rw-rw- controls    staff
q        109   0x2044     -Rrw-rw-rw- controls    staff
q         10   0x207a     -Rrw-rw-rw- controls    staff
q         11   0x24c4     -Rrw-rw-rw- controls    staff
q         12   0x24d7     -Rrw-rw-rw- controls    staff
q         13   0x251b     -Rrw-rw-rw- controls    staff
q         14   0x2fe8     -Rrw-rw-rw- controls    staff
q        115   0x3a65     -Rrw-rw-rw- controls    staff
q        116   0x967      -Rrw-rw-rw- controls    staff
q         17   0x98e      -Rrw-rw-rw- controls    staff
q        118   0x456c     -Rrw-rw-rw- controls    staff
q        669   0x194      -Rrw-rw-rw- controls    staff
q        620   0xe70      -Rrw-rw-rw- controls    staff
q         71   0x15d0     -Rrw-rw-rw- controls    staff
q        222   0x3586     -Rrw-rw-rw- controls    staff
q        173   0x5e37     -Rrw-rw-rw- controls    staff
q        624   0x5e4d     -Rrw-rw-rw- controls    staff
q        475   0x10d7     -Rrw-rw-rw- controls    staff
q        176   0x5ee3     -Rrw-rw-rw- controls    staff
q        277   0x4e22     -Rrw-rw-rw- controls    staff
q        428   0x25f3     -Rrw-rw-rw- controls    staff
q         29   0x3354     -Rrw-rw-rw- controls    staff
q        180   0x368f     -Rrw-rw-rw- controls    staff
q        131   0xb0f      -Rrw-rw-rw- controls    staff
q         82   0x47a5     --rw-rw-rw- controls    staff
q         83   0x4b83     -Rrw-rw-rw- controls    staff
q         34   0x4f6d     -Rrw-rw-rw- controls    staff
q         85   0x4539     -Rrw-rw-rw- controls    staff
q         86   0x67a1     --rw-rw-rw- controls    staff
q         37   0x4b7      -Rrw-rw-rw- controls    staff
q         38   0xd37      -Rrw-rw-rw- controls    staff
q         39   0x156c     -Rrw-rw-rw- controls    staff
q         40   0x2b62     -Rrw-rw-rw- controls    staff
op440m:~>rmq
---------------------------------------------------------------
Deleting message queues which are owned by user: controls ....
---------------------------------------------------------------
      Deleted message queue: 400
      Deleted message queue: 1
      Deleted message queue: 2
      Deleted message queue: 103
      Deleted message queue: 4
      Deleted message queue: 5
      Deleted message queue: 56
      Deleted message queue: 7
      Deleted message queue: 8
      Deleted message queue: 109
      Deleted message queue: 10
      Deleted message queue: 11
      Deleted message queue: 12
      Deleted message queue: 13
      Deleted message queue: 14
      Deleted message queue: 115
      Deleted message queue: 116
      Deleted message queue: 17
      Deleted message queue: 118
      Deleted message queue: 669
      Deleted message queue: 620
      Deleted message queue: 71
      Deleted message queue: 222
      Deleted message queue: 173
      Deleted message queue: 624
      Deleted message queue: 475
      Deleted message queue: 176
      Deleted message queue: 277
      Deleted message queue: 428
      Deleted message queue: 29
      Deleted message queue: 180
      Deleted message queue: 131
      Deleted message queue: 82
      Deleted message queue: 83
      Deleted message queue: 34
      Deleted message queue: 85
      Deleted message queue: 86
      Deleted message queue: 37
      Deleted message queue: 38
      Deleted message queue: 39
      Deleted message queue: 40
---------------------------------------------------------------
op440m:~>
  575   Thu Jun 26 18:24:28 2008 YoichiUpdatePSLFSS input ofset slider problem - fixed
I checked the FSS servo interface board and found that a LT1125CSW used to differentialize offset channel was broken (no virtual short).
So I replaced it. Now the slider is working.
The op-amp was hitting the rail. So it seems like we had been applying the maximum offset to the FSS input all the time.
The reason why the FSS loop still worked with the large offset is that the applied offset (~14V) is attenuated by a factor of 500 at the summing point.
  574   Thu Jun 26 14:06:00 2008 MashaUpdateGeneral500mW INNOLIGHT NPRO info
Below is the placement of 500mW INNOLIGHT NPRO mephisto laser. It is set up on the Symmetric Port table.
  573   Thu Jun 26 12:30:40 2008 JohnSummaryLockingCARM on REFL_DC
Idea:

Try REFL_DC as the error signal for CARM rather than PO_DC.

Reasoning:

The PO signal is dominated by sideband light when the arms are detuned so that any misalignment in the recycling cavity introduces spurious signals. Also, the transfer function from coupled cavity excitation to REFL signal is not so steep and hence REFL should give a little more phase. Finally, the slope of the REFL signal should make it easier to hand over to RF CARM.

Conclusion:


The REFL signal showed no clear improvement over PO signals. We've gone back to PO.


During the night we also discovered that the LO for the MC loop is low.
  572   Thu Jun 26 10:56:15 2008 Max JonesUpdatePEMRemoved Magnetometer
I removed the Bartington Magnetometer on the x arm to one of the outside benches. I'll be trying to determine if and how it works today. It makes a horrible high pitched sound which is due to the fact that the battery is probably 16 yrs old. It still works with ac power though and I want to see if it is still operating correctly before I ask to buy a new battery. Sorry for the bother.
  571   Thu Jun 26 01:10:18 2008 ranaUpdatePEMAlarm Handler indicates that dust level is high
In its first useful act, the Alarm Handler started beeping indicating that the dust particle
counts for particles of diameter less than 0.5 micron had exceeded 5000 /cu. ft.
Here's the
80 day trend of particles, temperature and humidity:
Attachment 1: Untitled.png
Untitled.png
  570   Thu Jun 26 01:08:22 2008 ranaConfigurationGeneralAlarm Handler Revived
I have revived the Alarm Handler by turning it on on op540m and adjusting the levels of
several of the alarming channels to not alarm (like laser power). The alarm levels are now
set to something reasonable and people should start actually paying attention to them.

I also removed the EO Shutter and Stacis alarm stuff since we don't use them.

To really get in and edit it, you have to close the Alarm Handler and edit the file
in /cvs/cds/caltech/alh/. It allows you to add/subtract useful channels and put in
guidance information.

If the alarm handler beeps about something, don't just close it or silence it, Steve. Just
fix it somehow (either set the threshold better or find the real cause).
Attachment 1: b.gif
b.gif
  569   Wed Jun 25 18:03:21 2008 YoichiConfigurationPSLFSS Input Offset slider problem
While working on the PMC scanning, I noticed that the FSS input offset slider is doing nothing.
I traced the signal flow and checked the cables/boards.
The slider changes the output voltage from a VMIVME4116 DAC in the PSL rack. This output voltage is confirmed to be correct at the FLKM64 connector. The signal is connected to the FSS servo interface box (D040423) trough a ribbon cable. However, the output from the interface box is always -27V regardless of the slider position.
Therefore, either the interface box (D040423) or the ribbon cable has a problem.
I will debug the interface box using an extension card when no one is working on the interferometer.
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