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ID Date Authordown Type Category Subject
  1286   Mon Feb 9 17:09:51 2009 YoichiUpdateComputersA bunch of updates for the network GPIB stuff.
During the work on ISS, we noticed that netgpibdata.py is very unreliable for SR785.
The problem was caused by flakiness of the "DUMP" command of SR785, which dumps the data from the analyzer to the client.
So I decided to use other GPIB commands to download data from SR785. The new method is a bit slower but much more reliable.

I also rewrote netgpibdata.py and related modules using a new class "netGPIB".
This class is provided by netgpib.py module in the netgpibdata directory. If you use this class for your python program, all technical details and dirty tricks are hidden in the class methods. So you can concentrate on your job.
Since python can also be used interactively, you can use this class for a quick communication with an GPIB instrument.

Here is an example.
>ipython #start interactive python
>>import netgpib #Import the module
>>g=netgpib.netGPIB('teofila',10) #Create a netGPIB object. 'teofila' is the hostname of
#the GPIB-Ethernet converter. 10 is the GPIB address.
>>g.command('ACTD0') #Send a GPIB command "ACTD0". This is an SR785 command meaning "Change active display to 0".
>>ans=g.query('DFMT?') #If you expect a response from the instrument, use query command.
#For SR785, "DFMT?" will return the current display format (0 for single, 1 for dual).
>>g.close() #Close the connection when you are done.

Sometimes, SR785 gets stuck to a weird state and netgpibdata.py may not work properly. I wrote resetSR785.py command to reset it remotely.
Wait for 30sec after you issue this command before doing anything.

I wrote two utility commands to perform measurements with SR785 automatically.
TFSR785.py commands SR785 to perform a transfer function measurement.
SPSR785.py will execute spectrum measurements.
You can control various parameters (bandwidth, resolution, window, etc) with command-line options.
Run those commands with '-h' for help.
It is recommended to use those commands even when you are in front of the analyzer, because they save various measurement parameters (input coupling, units, average number, etc) into a parameter file along with the measured data. Those parameters are useful but recording them for each measurement by hand is a pain.
  1287   Mon Feb 9 19:50:48 2009 YoichiConfigurationPSLISS disconnected
We are doing measurements on ISS.
The ISS feedback connector is disconnected and the beam to the MC is blocked.
  1291   Wed Feb 11 07:28:25 2009 YoichiUpdatePSLPA current and laser output
I think we should also plot the laser power at the MOPA output. The horizontal axis should be the absolute current value read from the PA current monitor channel, not the slider value.

This result is consistent with my hypothesis that the thermal effect is canceling the power change at low frequencies (see elog:1276).
But if it is really caused by thermal effect or not is still unknown.

I'd like to see a larger scan into the lower current region.


Quote:
I changed the PA current and measured laser output power (monitor PD signal).
The gain of ISS is 13dB
Attached figure is the relation of PA current and the average and standard diviation of laser output.
The average of output power decreas as current increase. It looks something is wrong with PA.
When current is -0.125, 0, 0.5, ISS become ocsilating. This looks to be changed from previous measurement.

I wrote matlab code for this measurement. The code is
/cvs/cds/caltech/users/kakeru/scripts/CS_evaluate.m
This function uses
/cvs/cds/caltech/users/kakeru/scripts/moveCS.m
  1292   Wed Feb 11 10:52:22 2009 YoichiConfigurationDAQC1:PEM-OSA_APTEMP and C1:PEM-OSA_SPTEMP disconnected

During the cleanup of the lab. Steve found a box with two BNCs going to the ICS DAQ interface and an unconnected D-SUB on the floor under the AP table.  It seemed like a temperature sensor.

The BNCs were connected to C1:PEM-OSA_APTEMP and C1:PEM-OSA_SPTEMP.

Steve removed the box from the floor. These channels can be now used as spare DAQ channels. I labeled those cables.

  1296   Thu Feb 12 11:21:54 2009 YoichiUpdateLSCLocking effort resumed
Last night, I restarted the locking work.
Quite some time was wasted by the disconnected REFL199 by Alberto for the cavity length measurement.
From now on, please put the interferometer back to the original state every day.
If possible, please refrain from changing the IFO settings (cabling, optics, etc).
It is also very important to always restore the full IFO alignment after you are done with your work.

While I was working on the optimization of the DD hand-off, the DRMI alignment got into a strange state.
Even when I did the whole dither alignment procedure from the beginning (from x-arm), the AS166Q did not go above 1000.
PRMI looks ok (SPOB goes above 1100). I could lock the DRMI but the lock position hops to other modes easily.
Manual tweaks of SRM did not help.
After running the whole alignment procedure several times in vain, I was too tired and went home.
I noticed that the single arm lock shows power drops again. There are some offsets in the arm lock loops.
This may have prevented the Michelson alignment from being optimal. I will check this today.
  1298   Thu Feb 12 17:43:33 2009 YoichiUpdateLSCSRC strangeness solved
I found the problem with the DRMI lock I had last night was caused by the zero gain in the PD11_I filter.
I don't know how it happened but putting it back to 1.000 made the DRMI lock far more stable and AS166Q got more than 3000.

I also re-centered POY PD to remove the offset in the y-arm loop. The large power drops while y-arm is locked by itself were eliminated.
  1301   Fri Feb 13 13:35:38 2009 YoichiUpdateLSCLocking status
Yoichi, Jenne, Alberto, Rob

Last night, the locking proceeded until the CARM -> MC_L hand-off.
However, the MC_F gets saturated (as expected) and the IFO loses lock soon after the hand-off.
So we need to offload MC_F.
We ran the offloadMCF script, but it did not work, i.e. just waiting for CARM mode.
Looks like an EPICS flag is not set right.
  1305   Sun Feb 15 09:35:00 2009 YoichiUpdateLSCLocking status

Quote:

I found a '$<' in the offloadMCF script. I don't know precisely what that construct means, but I think it caused the script to wait for input when it shouldn't.


'$<' acts like 'read' in csh. I might have put it in the offloadMCF script to debug the behavior of the script.
Sorry I probably forgot to remove it from the script when I left.
  1309   Mon Feb 16 14:12:21 2009 YoichiUpdateLSCFE system rebooted

Quote:

I can't restart the MC autolocker on c1susvme2 because it doesn't let me ssh in. I tried to reboot it a few times but it didn't work. Once you restart it, it becomes inaccessible and doesn't even respond to pinging. Although the controls for the MC mirrors are on.

The mode cleaner stays unlocked.


MC autolocker runs on op340m, not on c1susvme2.
I restarted it and now MC locks fine.
Before that, I had to reboot c1iool0 and restore the alignment of the MC mirrors (for some reason, burt did not restore the alignment properly, so I used conlog).
  1310   Mon Feb 16 15:54:07 2009 YoichiUpdateComputersmedm directory wiped on nodus

Quote:
I accidentally did an 'rm -rf' on the medm directory in nodus, instead of on my laptop as was intended.

I then did an svn checkout. So everything should be current as of the last update, but I am sure that
we have not done a checkin on all of the latest screen enhancements. So...we may have to revert to the
Sunday morning tar to get the latest changes back.


Indeed, some changes to the medm directory I made were lost.
It was my fault not to check-in those changes.
I asked Alan to restore the directory from the daily rsync backup.
However, the backup job executed this morning have already overwritten the previous (good) backup with the current (bad) medm directory, which Rana restored from the svn. Alan will ask Stuart and Phil if there is still older backup remaining somewhere.

Anyway, I realized that we should stop the backup cron job whenever you think you made a mistake on /cvs/cds/ directory to prevent unwanted overwriting.
The procedure is:
(1) Login to fb40m
(2) Type 'crontab -e'. Emacs will open up in the terminal.
(3) Comment out the backup job (insert # at the beginning of the line containing /cvs/cds/caltech/scripts/backup/rsync.backup ).
(4) Save the file (Ctrl-x Ctrl-s) and exit (Ctrl-x Ctrl-c).

I will post this information on the wiki.
  1316   Tue Feb 17 05:20:11 2009 YoichiUpdateLSCLocking
Since we excluded *.snap and *.req files from the svn control in the medm directory and these were not restored by the svn co, the burt part of the align/mis-align scripts were not working correctly this evening. So I recreated .req files and cooked up some mis-aligned .snap files.
After some cut-and-try work, I was able to run the dither alignment scripts fine.

Due to the above mentioned delay, the locking work started around midnight.

Tonight, the DD hand-off was not robust. I spent sometime to optimize this.
After the optimization, the locking proceeded to the DC CARM/DARM control state stably.
The CARM->MCL hand-off failed because the LSC-MC offset button was off.
I added a line to turn on the button in the ontoMCL script.
Today, the offloadMCF script worked fine.

Next, the cm_step script stumbled on the "ENGAGERIZING" of the AO path.
I got a hunch that the AO path might not be connected to the MC board.
Indeed, OMC_OSC_FM was connected to the IN2 of the MC board. Looks like it was used for the optimization of the modulation frequencies.
Probably I had the hunch because I did it Smile

I was able to increase the arm power up to 3.9.
The script failed when it tried to switch the CARM signal from TR_DC to SPOB_DC.
I haven't tackled on this issue yet.
  1317   Wed Feb 18 03:17:40 2009 YoichiUpdateLSCLocking
Yoichi, Kakeru,

Last night, the cm_step script failed at the hand-off of CARM error signal from TR_DC to PO_DC.
This was fixed by reducing the PO_DC gain by a factor of 2.
Currently the script fails when changing C1:LSC-DEMOD_GAIN to zero.
To be honest, I don't fully understand the purpose of this step.
  1318   Wed Feb 18 03:25:25 2009 YoichiUpdateComputersmedm directory back
I restored the medm directory from the backup on the tape.
The directory had an svn property svn:ignore set and the value of the property included *.snap and *.req.
This resulted in the exclusion of those files from the repository.
I fixed this problem by changing the property of all the directories under /cvs/cds/caltech/medm.
After fixing several other svn problems, the current medm directory contents were checked in to the repository.
  1323   Thu Feb 19 04:16:17 2009 YoichiUpdateLSCLocking status
Rob, Yoichi

We checked the CM-MC cross over just before turning off the moving zero.
There was a slight bump in the gain of the MC_L loop at (I believe) the optical spring freq. (~400Hz) just below 0 dB. The phase margin there was very thin.
Removing the moving zero will increase the bump more and make the loop unstable.
Rob suggested to increase the AO gain a bit more.

To see if the AO path is really working, I connected the OUT2 of the MC board to a spare DAQ channel (C1:PEM-OSA_APTEMP).
I confirmed that the PO_DC signal is actually coming to the AO path input of the MC board.
I also hooked up the SR785 to the A excitation channel of the common mode board, so that we can measure the loop gain of the AO path.
After these preparation, the lock acquisition process became somewhat unstable. The ifo loses lock randomly at various places in the lock acquisition steps.
So, as of 4:00 am, I have not gotten a chance to try Rob's suggestion nor the TF measurement with SR785 yet.
I will continue the work tomorrow (i.e. tonight ??).

  1325   Thu Feb 19 16:29:43 2009 YoichiUpdateComputersMartian wireless router bad
The Martian wireless router is dead.
I rebooted it several times, but it hangs up in a minute.
I will ask steve to buy a new one.
  1329   Fri Feb 20 03:52:23 2009 YoichiUpdateLockingLocking Tonight
Yoichi, Peter

Tonight, we had a problem with the DD hand off.
It failed when the RG filters of MICH for the bounce-roll modes are engaged.
The reason for the failure was that the MICH UGF was too low (~10Hz).
As in the Peter's elog entry, we found that the AS PDs are mis-centered.
Even after we fixed the centering, the MICH UGF was still too low. So we increased the MICH feedback gain by a factor of 10.
The reason for the gain decrease is unknown. It seems almost like the BS coils get weaker.
I checked the UGF of the BS OL loops. These are around 4Hz, so fine. We should check the HWP on the AP table tomorrow.

After the DD hand-off goes ok, the switching of DARM signal from DC to RF failed.
I found that the gain and the polarity of the RF signal were wrong.
AS166 is one of the PDs we found mis-centered (and re-centered). But how can you flip the sign of the signal ?

After this, the cm_step script goes until the activation of the moving zero, but fails when the arm power is increased to 0.7.
Also the ontoMCL script succeeds only 50% of the time.
  1330   Fri Feb 20 19:31:16 2009 YoichiUpdateLSCMICH low gain problem
Last night, we found that MICH UGF was too low. Even after re-aligning the PDs, it was still too low.
Today, I compared the UGFs of MICH and PRC when in the DRMI configuration locked with the single demod. signals.
In this configuration, MICH signal comes from REFL33Q and the PRC signal comes from REFL33I (the same PD).
The PRC UGF was about 100Hz whereas MICH was only ~10Hz.
Since they uses the same PD, the low gain is not caused by the PD.
I checked conlog history and confirmed there is no change in the MICH->BS path in the last few days.
I also checked the svn history of chans directory for changes in filters. Nothing problematic found.

Then I noticed that the susvme computers were overloaded.
This time, I rebooted all the FE computers just in case.

Then the MICH gain was somewhat recovered (by a factor of 3 or so). Don't know why.

I adjusted the DD_handoff script to set the MICH gain to 0.7 before the bounce-roll filter is engaged.
  1334   Tue Feb 24 02:23:40 2009 YoichiUpdateLockingLocking - MC board bad
Rob, Yoichi, Alberto, Kiwamu, Kakeru

We found that the OMC alignment feedback was on for the POS X loop even though the OMC was not locked.
This caused the PZT mirror to be tilted in yaw a lot. This was probably the reason for the mysterious shift in the AS beam last week, because the AS RF beam is picked up after this PZT mirror.
Rob aligned the OMC and we re-centered the AS PDs and the CCD.
This changed the DARM RF gain, so we changed it from 3 to 1. This gain used to be -1. It is still not understood why the polarity was changed.
The MC length was changed ? We should check the sideband transmission.

After this, we reached to the arm power 4. But the IFO loses lock immediately after the moving zero is turned off.
At this stage, the CARM loop bandwidth is supposed to be high enough that the moving zero is no longer necessary.
However, when we measured the MCL loop gain with several different AO path gains, the loop shape did not change at all.
This led us to suspect the AO path may not be connected. The cabling from the common mode board to the MC board seemed ok.
We tested the signal flow in the MC board using a signal generator and an oscilloscope.
Then we found that a signal injected to the IN2 (AO path) does not reach to the TP1A (right after the boost stages), though the signal is visible in the OUT2 (monitor BNC right after the initial amplifier (B-amp) for the AO path). The signal from IN1 (MC REFL) can be observed at TP1A. This means something is broken between the B-amp and the sum-amp in the AO path.
We will check the MC board tomorrow.
  1336   Wed Feb 25 03:10:24 2009 YoichiUpdateLockingLocking status
Rob, Yoichi, Kakeru, Kiwamu

Tonight, CARM -> MCL hand off was not stable. The MCF signal monotonically went up to +2V after CARM and MCL gain was turned down to zero.
This was repeatable and it only goes up (not down).
After a while, we found that putting sleep (~5sec) between the zeroing of CARM gain and MCL gain prevents this problem.

Handing off of CARM error signal from TR to PODC was also not robust.
It seems that the suitable gain changes every time.

tdsavg started to exit with errors. We rebooted fb40m.
When tdsavg returns an error, the cm_step script tries to write NaN into SPOB DC offset.
To prevent this, I put the tdsavg in a while loop which runs until tdsavg returns something other than NaN.

I was able to hand off to PODC several times, but could not proceed further because the IFO lost lock soon.
  1338   Thu Feb 26 00:36:53 2009 YoichiSummaryComputersC1:LSC-TRX_OUT broken (and fixed later).
Today, Kakeru tried to convert C1:LSC-TRX_OUT and C1:LSC-TRY_OUT to DAQ channels.
He edited C1LSC.ini in the chans/daq directory to add the channel but it did not work.
Then he reverted the file back to the original one.
But after we still could not access these channels from dataviewer nor tds tools.
We restarted daqd and tpman on fb40m, but the problem persisted. Even rebooting the whole fb40m did not help.
After inspecting the log file of daqd, it was clear that tpman was failing to create test points for those channels.
I rebooted c1daqawg and then restarted tpman and daqd on fb40m again.
This time, the problem went away.
  1339   Thu Feb 26 01:24:44 2009 YoichiUpdateComputersMartian wireless is back
Today, a new wireless router arrived.
I configured and installed it. Now the martian wireless network is back.
I updated the wiki page about the wireless network.
http://lhocds.ligo-wa.caltech.edu:8000/40m/Network
  1340   Thu Feb 26 19:20:08 2009 YoichiConfigurationGeneralETMX camera centered. POX, POY PDs centered
Alberto, Yoichi

We centered the ETMX camera.
Alberto centered the POX and POY PDs.
We also updated the offset values of PD3 and PD4.
  1341   Thu Feb 26 19:59:23 2009 YoichiUpdateLockingDaytime locking
Osamu, Yoichi

We tried locking today from about 2PM.
It took about 1000sec on average to acquire the initial lock.
After the initial lock is achieved, the hand-off/ramp-up steps were reasonably robust, although the AS beam sometimes fluctuates a lot (not good for mental health).

Like last night, the IFO loses lock at around arm-power=8.
We measured the CARM AO path loop gain at arm-power=4. We used the SR785 connected to the A-excitation channel of the common mode board through my TFSR785.py script.

The first attachment is the transfer function measured right after the arm power was ramped up to 4.
The overall bandwidth of the CM servo is only 400Hz. Note that since this is the loop gain of only the AO path, the low frequency gain is eaten by the MCL path.
The second attachment is the same transfer function measured after the AO path gain was increased by 6dB.
It is evident that the AO path is working.
We increased both the AO path and MCL gain by 18dB. The third attachment is the AO path TF in this state.
We then increased the arm power but lost lock at arm-power=6. We should have checked the DARM loop too.
BTW, these plots are automatically generated when you use TFSR785.py for transfer function measurements.


I added -notickle option to c1_watch_dr_bang, since tickling seems to be not necessary during the daytime (actually the initial lock was easier with no tickling).

As the construction work in the next building is now calmed down, I think it is ok to do locking during the day time, though I still plan to come at night.
The improvement of my brain efficiency during the day time may compensate for the longer wait time for initial lock.
Attachment 1: CM1.png
CM1.png
Attachment 2: CM2.png
CM2.png
Attachment 3: CM3.png
CM3.png
  1342   Thu Feb 26 20:09:32 2009 YoichiHowToComputersSR785 python scripts now produce plots
I updated the python scripts to remotely perform measurements with an SR785.
Now these scripts can plot the results immediately using python's matplotlib capability. The sample plots can be seen in my previous elog entry.
In addition to the transfer function (TFSR785.py) and spectrum measurement (SPSR785.py) scripts, I also wrote a script for time series measurements (TSSR785.py).
This is useful when you want to check the signal level flowing in the channels before determining the excitation amplitude.
TSSR785.py will measure and show the time series and histogram of the signal measured by the SR785.
More detailed usage is explained in this wiki page:
http://lhocds.ligo-wa.caltech.edu:8000/40m/netgpib_package
  1344   Mon Mar 2 03:57:44 2009 YoichiUpdateLockingSunday night locking
Tonight's locking started with a boot fest of the FE computers which were all red when I came in.
It also took me sometime to realize that C1:IOO-MC_F was returning always zero to tdsavg, causing the offloadMCF script to do nothing.
I fixed this by rebooting c1iovme and c1iool0.

Like Rob on the thursday night, I was only able to reach arm power around 10.
This time, I turned down the MC WFS gain to 0.02 (from 0.3).
I also checked gains of most of the loops (MICH, PRC, SRC, DARM, CARM-MCL, CARM-AO).
All the loops looked fine until the lock was lost suddenly. Also the spectrum of MC_F did not change as the arm power was ramped up.
Actually, I was able to reach arm power=10 only once because I spent a long time checking the loop gains and spectrum at fine steps of the arm power.
So it is quite possible that this loss of lock was just caused by a seismic kick.
  1346   Mon Mar 2 21:16:32 2009 YoichiUpdateLockingLow-gain High-gain PD switching may not be working well
Osamu, Yoichi

This afternoon, I run the locking script while doing calculations for the upgrade.
The IFO lost lock even at lower arm powers (around 6) if it was operated for a while (~ 5min).
It seemed as if there were some intermittent glitches (seismic? laser?) causing the lock losses.
We also saw once the TRX and TRY signals saturated at around arm power = 11 when there was a large fluctuation in the arm power.
Osamu suggested that it looked like the high-gain to low-gain PD switching was not working.

I won't come tonight as I may have caught a cold, but if someone comes tonight, it is worth checking the PD switching.
  1350   Tue Mar 3 19:26:44 2009 YoichiUpdateLockingLow-gain High-gain PD switching may not be working well
I checked the switching of the QPDX from high gain to low gain.
Switching happens as expected, but the low gain QPDX output was very low compared to QPDY.
Also the digital gain for the high gain TRX was not matched with the low gain one. So when the switching happens, there is a large jump in the TRX.

I also found that the offset values for the low gain QPDX were totally wrong. I adjusted it.
Then I removed a beam splitter in front of the QPDX to increase the power falling on it.
But still the low gain QPDX output is four times lower than the low gain QPDY.

I'm still working on it. So don't expect the switching to work correctly at this moment.
I'm planning to be back after the dinner.


Quote:
Osamu, Yoichi

This afternoon, I run the locking script while doing calculations for the upgrade.
The IFO lost lock even at lower arm powers (around 6) if it was operated for a while (~ 5min).
It seemed as if there were some intermittent glitches (seismic? laser?) causing the lock losses.
We also saw once the TRX and TRY signals saturated at around arm power = 11 when there was a large fluctuation in the arm power.
Osamu suggested that it looked like the high-gain to low-gain PD switching was not working.

I won't come tonight as I may have caught a cold, but if someone comes tonight, it is worth checking the PD switching.
  1351   Tue Mar 3 23:59:26 2009 YoichiUpdateLockingLow-gain High-gain PD switching may not be working well

Quote:
I checked the switching of the QPDX from high gain to low gain.
Switching happens as expected, but the low gain QPDX output was very low compared to QPDY.
Also the digital gain for the high gain TRX was not matched with the low gain one. So when the switching happens, there is a large jump in the TRX.

I also found that the offset values for the low gain QPDX were totally wrong. I adjusted it.
Then I removed a beam splitter in front of the QPDX to increase the power falling on it.
But still the low gain QPDX output is four times lower than the low gain QPDY.

I'm still working on it. So don't expect the switching to work correctly at this moment.
I'm planning to be back after the dinner.



This sounds like the QPD whitening gain sliders may be stuck. The slider twiddling script should be run, or the sliders should be twiddled by hand.
  1352   Wed Mar 4 03:37:51 2009 YoichiUpdateLockingLow-gain High-gain PD switching may not be working well

Quote:

This sounds like the QPD whitening gain sliders may be stuck. The slider twiddling script should be run, or the sliders should be twiddled by hand.


Yes, it was indeed the whitening gain slider problem.
I moved them and the QPDX gain went up suddenly. I reinstalled the BS in front of the QPDX and adjusted the offsets, gains accordingly.
Now the high-gain to low-gain switching is fine.
  1353   Wed Mar 4 03:50:17 2009 YoichiUpdateLockingStill won't go above arm power 10
Yoichi, Kentaro

The IFO still loses lock at around arm power 10.
I attached time series of various error signals when losing lock.
In all of the three cases, both of the arm powers go up rapidly just before losing lock.
(The first attachment was taken before I fixed the QPDX switching, so you can see saturation in TRX.)
But PD1_DC (the DC power in the PRC) did not go up in the third case.

I should also check correlations with laser power, CARM length (OSEM signals), seismic noise etc.
Attachment 1: lockLoss1.png
lockLoss1.png
Attachment 2: lockLoss2.png
lockLoss2.png
Attachment 3: lockLoss3.png
lockLoss3.png
  1356   Wed Mar 4 17:59:14 2009 YoichiConfigurationComputersezca tools and tds tools work around
Some of ezca commands and tds commands sporadically fail with a segmentation fault on linux machines.
As far as I know, ezcawrite, ezcastep, ezcaswitch, and tdswrite have this problem.
These are commands to write values into epics channels. So usually people do not check the exit status of those commands in their scripts.
This could cause incomplete execution of, for example, down scripts.
Ideally, this problem should be fixed in the source codes of the problematic commands.
However, I don't have a patience to wait it to happen, and I needed to fix these problems immediately for the lock acquisition.
So I resorted to a hacky solution.
I renamed those commands to *.bin, e.g. ezcawrite -> ezcawrite.bin.
Then wrote wrapper scripts to repeatedly call those commands until it succeeds.
For example, ezcawrite now looks like,
#!/bin/csh -f
setenv POSIXLY_CORRECT
while (! { ezcawrite.bin $* })
      echo "Retry $0 $*"
end
So, when ezcawrite.bin fails, the command retries it and show a message "Retry ....".

If you need to call the original commands, you can always do so by adding ".bin" at the end of the command name.
Currently the following commands are wrapped.
ezcawrite, ezcaservo, ezcastep, ezcaswitch, tdswrite, tdssine.

Please let me know if you have any trouble with this.
  1361   Thu Mar 5 05:07:09 2009 YoichiUpdateLockingWednesday night locking
Tonight, I was having a problem with the PO_DC hand-off.
It fails most of the time.
I increased the averaging time for the PD1_DC offset measurement.
I also wrote a script to match the gain of the transmission DC and the PO_DC signals.
This script (/cvs/cds/caltech/scripts/CM/matchPODCGain ) measures the gains of the old (TRX+TRY) and new (PO_DC) signals at 150Hz and returns the optimal value to be put into the input matrix.
cm_step script calls matchPODCGain to determine the matrix element value for the PO_DC signal.

Even with this script, the hand-off was still unreliable.
I checked the AO path loop gain just before the hand off. It looked normal.
Then I realized that the oscilloscope I hooked up to the PO_DC signal using a T-BNC may be introducing some noise into the channel.
So I removed it. Then the PO_DC hand off went well at least once.
The IFO still loses lock at around arm power 10.

I attached time series of the latest lock loss. The second attachment is a zoom of the first one.
This time, there is a glitch in the ETM feedback signals, which is also present in the DARM and CARM and error signals.
I saw this kind of glitches several times today.
Attachment 1: lockLoss5.png
lockLoss5.png
Attachment 2: lockLoss5-zoom.png
lockLoss5-zoom.png
  1364   Fri Mar 6 05:44:14 2009 YoichiUpdateLockingLocking distracted by the QPD whitenning problem again
Tonight, I was able to ramp up the arm power to around 20. Then the DARM loop started to oscillate and the IFO lost lock in a few seconds.
I repeated this several times, then realized that the transmission QPDs were not working properly again due to the well known sticky slider problem.
I should have run slider_twiddle script. Since the DARM RF signal is normalized by the sqrt(TRX+TRY), it is reasonable that the DARM loop got unstable.

The fact that I was able to go up to arm power = 20 means there is nothing saturating below this power level.
  1365   Fri Mar 6 15:23:39 2009 YoichiUpdateLockingLocking distracted by the QPD whitenning problem again
By looking at the time series of DARM signal at the time of a lock loss, the oscillation frequency was about 3.5kHz (see the attm1 and its zoomed version attm2).
I will measure the DARM loop gain around this frequency next.


Quote:
Tonight, I was able to ramp up the arm power to around 20. Then the DARM loop started to oscillate and the IFO lost lock in a few seconds.
I repeated this several times, then realized that the transmission QPDs were not working properly again due to the well known sticky slider problem.
I should have run slider_twiddle script. Since the DARM RF signal is normalized by the sqrt(TRX+TRY), it is reasonable that the DARM loop got unstable.

The fact that I was able to go up to arm power = 20 means there is nothing saturating below this power level.
Attachment 1: lockLoss3.pdf
lockLoss3.pdf
Attachment 2: lockLoss3-zoom.pdf
lockLoss3-zoom.pdf
  1366   Fri Mar 6 18:14:58 2009 YoichiUpdateComputersawg not working
Starting from this afternoon, the awg is not working.
I rebooted FE computers, c0daqawg as well as tpman and daqd processes on fb40m several times.
But the problem is still there.
I sent an email to Alex.
  1367   Fri Mar 6 18:22:42 2009 YoichiSummaryComputersScripts to restart the FE computers
While doing locking, the FE computers are overloaded sometimes and I have to reboot them.
Being sick of logging into the FE computers one by one to start front end codes, I wrote scripts to do this automatically.
The scripts are in /cvs/cds/caltech/scripts/FE/.
For example, you can restart c1lsc by typing
restartFE c1lsc
You can give multiple computer names to the restartFE command like,
restartFE c1lsc c1asc c1susvme1

To restart all the FE computers, type
restartFE all

For the scripts to work properly, the computers have to accept login, i.e. you either have to power cycle the computers or push "Reset" buttons on the RFMNETWORK medm screen prior to running the scripts.
  1368   Fri Mar 6 18:26:37 2009 YoichiConfigurationComputersezca tools and tds tools work around
I updated the wrapper scripts so that they do not retry more than 6 times.
Otherwise, the wrapper scripts loop over infinitely when you give wrong arguments.



Quote:
Some of ezca commands and tds commands sporadically fail with a segmentation fault on linux machines.
As far as I know, ezcawrite, ezcastep, ezcaswitch, and tdswrite have this problem.
These are commands to write values into epics channels. So usually people do not check the exit status of those commands in their scripts.
This could cause incomplete execution of, for example, down scripts.
Ideally, this problem should be fixed in the source codes of the problematic commands.
However, I don't have a patience to wait it to happen, and I needed to fix these problems immediately for the lock acquisition.
So I resorted to a hacky solution.
I renamed those commands to *.bin, e.g. ezcawrite -> ezcawrite.bin.
Then wrote wrapper scripts to repeatedly call those commands until it succeeds.
For example, ezcawrite now looks like,
#!/bin/csh -f
setenv POSIXLY_CORRECT
while (! { ezcawrite.bin $* })
      echo "Retry $0 $*"
end
So, when ezcawrite.bin fails, the command retries it and show a message "Retry ....".

If you need to call the original commands, you can always do so by adding ".bin" at the end of the command name.
Currently the following commands are wrapped.
ezcawrite, ezcaservo, ezcastep, ezcaswitch, tdswrite, tdssine.

Please let me know if you have any trouble with this.
  1369   Sat Mar 7 16:50:25 2009 YoichiUpdateComputersNot even data retrieval working
Now our digital system is really in trouble.
We can't even get data from tp channels.

I did another round of computer reboots, this time including the RFM bypass switch, c0daqctrl, c0dcu1 and fb40m itself.
But the problem still persists.

I guess there is nothing I can do until Alex comes in.
  1374   Mon Mar 9 12:04:18 2009 YoichiUpdateComputersTPs and AWG are back
I had to do one more reboot of tpman and daqd to get the TPs working.
I confirmed the alignment scripts run fine.

Now the oplevs of some optics are largely mis-centered. Alberto and I will center them after lunch.
  1380   Mon Mar 9 23:13:22 2009 YoichiUpdateComputer Scripts / Programstdsdata doesn't work

Quote:

We confirmed that new tds(/cvs/cds/caltech/apps/linux/tds_090304/) works well on linux 64, and replaced it to /cvs/cds/caltech/apps/linux/tds/

The old /cvs/cds/caltech/apps/linux/tds is put in /cvs/cds/caltech/apps/linux/tds.bak

 The tdscntr.pl in the new tds was probably the one from LLO, which is actually the version I sent to Tobin. It had paths and channel names defined for the LLO. So I copied back my original 40m version.

  1382   Tue Mar 10 04:55:41 2009 YoichiUpdateLockingLocking: 3.7kHz large oscillation
Yoichi, Jenne, Alberto,

As I reported on the last Thursday, there is a large oscillation in CARM and DARM error signals (attm1).
I put notch filters (3.75kHz, Q=10, 30dB) in the CARM and DARM loops. This let us go up to the arm power of more than 20 and stay there for a while.
The dashed curves in the attm1 are the spectra when the notches are off, and the solid curves are when the notches are used.
We could somewhat suppress the DARM peaks but not CARM.
Of course this is clearly not a good solution. We should find the cause of the oscillation and kill it.

Attm2 is the spectrum of the PO_DC signal flowing in the CM board measured by the SR785. More specifically, CH1 is TP1A and CH2 is TP2A of the CM board.
This was taken right after the AO path was engaged. At this stage, the AO path gain is very low. But you can already see a seed of the oscillation in the spectrum.

Attm3 shows the same spectra taken after the arm power is increased to 4 but before the PO_DC hand off. You can see large peaks around 3.75kHz.
After this, the peaks grow as the power goes up.

Attm4 is the loop gain of the AO path after the PO_DC hand off (arm power = 4).
Attm5 is the zoom of the same TF around 3.7kHz. Clearly there is something wrong at this frequency. We should check the CM board and the MC board as well as the SPOB PD.

One time I was able to go up to arm power = 27 or so. At this power level, the DARM loop started to oscillate, probably, around the UGF.
However because of the 3.7kHz problem, we can't stay at this power level long enough to make diagnostic measurements (like open loop TF).
We should tackle the 3.7kHz issue first.
Attachment 1: CARM_DARM_Spectra.pdf
CARM_DARM_Spectra.pdf
Attachment 2: PODC_Spe_AOPath_Engaged.png
PODC_Spe_AOPath_Engaged.png
Attachment 3: PODC_Spe_before_PODC_handoff.png
PODC_Spe_before_PODC_handoff.png
Attachment 4: AOGain3.png
AOGain3.png
Attachment 5: AOGain2.png
AOGain2.png
  1388   Wed Mar 11 16:53:48 2009 YoichiUpdateLockingJunks in around kHz
Rana, Yoichi

Last night, we tried to find out the source of the kHz region peaks in the DARM and CARM error signals.
These peaks are also present in the error signal of the single arm locking by RF (both X and Y).
The attachment 1 shows spectra of MC_F and XARM error signal when XARM is locked by the POX PDH signal.
There is a sharp peak at 3.8kHz in MC_F. This peak was there in a reference spectrum taken on June 24 2008.

In the XARM error signal, there is also a broad peak around 3.8kHz. This peak moves between 3.75kHz and 3.8kHz from time to time.
(the brown curve was taken when the peak moved to 3.75kHz).
Also there is a notch like structure at 3.8kHz in the XARM error spectrum. Looks like the peak in the MC_F is creating a notch here, but
no idea why.

We tapped on the PSL table, the end chambers and the SPOB table and looked at the spectra to see if there is any change.
Rana also developed a cool Walkie-Talkie excitation technique, where he put one of the walkie-talkies on the PSL table by the MZ and yelled at the other one while looking at a DTT screen in the control room.
None of these had any effect on the XARM error, while MC_F responded to the disturbances.

We also turned on and off the steering mirror PZT closed loop buttons, moved the PMC, MZ and the ISS gain sliders and changed the MC gain, offset.
Nothing affected the XARM error.

Osamu found old spectra of the XARM signal (attm2). The legends say DARM but these are XARM signals.
Almost the same structures can be seen including the notch at 3.8kHz. Seems like it's been like this for long time.

We should check, RF-AM, MC coil dirivers, Piezo-Jena noise etc.
Attachment 1: MC_F-XARM.pdf
MC_F-XARM.pdf
Attachment 2: old-xarm.pdf
old-xarm.pdf
  1390   Wed Mar 11 22:57:48 2009 YoichiUpdateLockingCalibrated XARM error signal spectrum
I did a rough calibration of the XARM error spectrum.
See the attached calibrated spectrum.

I started from this Rana's elog entry.
http://www.ldas-sw.ligo.caltech.edu/ilog/pub/ilog.cgi?group=40m&task=view&date_to_view=04/07/2005&anchor_to_scroll_to=2005:04:07:20:28:36-rana

I first injected a 20Hz sin signal into C1:SUS-ETMX_LSC_EXC and measured the response to the ETMX SUSPOS.
Using the calibration of the SUSPOS given in the above entry, I calibrated the ETMX coil actuation efficiency.
It was 3.4e-12 m/cnt @20Hz for C1:SUS-ETMX_LSC_EXC.

Then I locked the X-arm and injected a calibration peak at 20Hz.
From the ratio of the peaks in C1:SUS-ETMX_LSC_IN2 and C1:LSC-XARM_IN1, I calibrated the X-arm error signal to be 4.2e-13 m/cnt.
We have to also take into account the cavity pole of the arm, 1525Hz (the design value, may not be actual).
So I used the following calibration in the DTT:

G: 4.2e-13
P: 1525
Z:

Note that the attached spectrum shows the actual motion of the X-arm (or equivalent frequency noise) after suppressed by the feedback servo,
unlike conventional noise spectra showing "virtual" displacement which would have been induced in the absence of servos.
Attachment 1: XarmErrorSpeCalibrated.pdf
XarmErrorSpeCalibrated.pdf
  1393   Thu Mar 12 02:18:42 2009 YoichiUpdateLockingMC_I spectra (RF_AM)
I took several spectra of MC_I signal (see attm1).

The blue curve is when the MC was locked. The green curve (RF_AM) shows the MC_I spectrum when the MC is unlocked and MC2 is mis-aligned,
so that no resonance should happen. The brown curve is when the PSL shutter was closed (dark noise).
There are some structures in the green curve but not at 3.8kHz.

The second attachment compares the MC_I spectrum (the same as the green one in the first attachment) with the Xarm error signal.
Of course these two spectra were taken at different times.

Some of the peaks in the X-arm error signal seem to be coming from the MC RF_AM.
Attachment 1: MC_I_Spe.png
MC_I_Spe.png
Attachment 2: MC_I-Xarm.png
MC_I-Xarm.png
  1394   Thu Mar 12 15:57:53 2009 YoichiUpdateIOOMC drift is terrible
Yoichi, Osamu,

Last night's locking work was totally interrupted by the sabotage by the MC.

First, after I measured the RF_AM, the MC alignment was somehow shifted largely and the MC did not lock to TEM00 mode.
I only mis-aligned MC2 to measure the RF_AM, but the MC reflection beam was also shifted (looking at the WFS QPD), that means MC1 was mis-aligned somehow.
Moreover, even when the MC is not locked, i.e. no feedback to the mirrors, the OSEM values of the MC mirrors (all of them) drift a lot in 10min scale.
I was totally puzzled. So I rebooted c1iovme and c1sosvme. Then this strange drift of the OSEM values stopped.
Even though, the MC tended to lose lock within ten minutes because the WFS QPDs were not centered.
We did several iterations of re-centering and finally the MC started to stay locked happily. The MC reflection beam was symmetric.

Then this morning when I came in (to be honest, afternoon), the MC reflection looked asymmetric again. The WFS QPDs were mis-centered again.
The attached files show an 8-hour trend of various MC related signals.
There was a half-degree temperature change starting from around 11AM. Corresponding to that, the IOO-QPD signals drifted indicating that the PSL beam pointing
was shifted. The MZ PZT signal shows a similar trend, so the beam pointing may have been shifted by the MZ (not sure).
The MC WFS, transmission QPD signals show the same trend.
This is too bad.

Right now, the PSL beam pointing is monitored by the QPDs detecting the transmitted beam through the first mirror of the periscope.
This means even if we can track the beam pointing drift with the QPDs, we can't correct the beam pointing using the periscope mirrors.
I don't want to touch the MZ mirrors for this purpose.
I propose to put a pick-off mirror after the second mirror of the periscope to send light to the IOO-QPDs. This way, we can use the periscope
mirrors to restore the beam pointing screwed up by the MZ.
Attachment 1: MC_Drift-1.pdf
MC_Drift-1.pdf
Attachment 2: MC_Drift-2.pdf
MC_Drift-2.pdf
  1395   Thu Mar 12 18:44:02 2009 YoichiUpdatePSLMZ aligned
The MC lost the alignment somehow this afternoon.
So I thought it was good time to touch the MZ because I had to align the MC using the periscope anyway.

I mainly touched the mirror with a PZT. The MZ reflection went down from 0.5 to 0.3.
  1396   Thu Mar 12 18:48:37 2009 YoichiUpdateIOOMC aligned but ...
After the MZ alignment, I aligned the MC with the periscope mirrors.
It looked like the MC mis-alignment was mainly caused by the input beam change.
So I left the MC mirrors as they were to keep the output beam pointing.
However, after I finished the alignment, the MC output beam was too low on the Faraday.
Also the X-arm did not lock to TEM00 mode. So the MC mirrors must have also shifted to a weird alignment state.
I should have restored the MC mirror alignment to a good state using the OSEM DC signals.

Rana came in and restored the MC mirror alignment using the SUS drift mon.
He and Kakeru is now working on the periscope to align the beam into the MC.
  1399   Fri Mar 13 05:16:21 2009 YoichiUpdateLockingLocking update
Yoichi, Osamu,

With adjustments of the loop gains during the CARM offset reduction, the IFO reaches arm_power = 25 sort of robustly unless the 3.8kHz oscillation rings up.
At arm_power = 25, the CARM and DARM start to oscillate at around 400Hz. Probably I need more gain tweaks.
Annoying thing is that the 3.8kHz oscillation sometimes rings up suddenly and kills the lock.
This can happen anywhere above arm_power = 6 or so.
Because of a strange structure in the CARM loop gain around 3.8kHz, we cannot increase the CARM UGF beyond 1kHz.
The attached plots are the AO path open loop transfer function (attm2 is the zoom of attm1) measured at arm_power = 13.

Tomorrow, I will lock the X-arm and measure the transfer function from the AO path input to the X-arm error signal to see
if there is the same structure at 3.8kHz (X-arm error signal has the 3.8kHz peak).
Attachment 1: AOTF2.png
AOTF2.png
Attachment 2: AOTF2-zoom.png
AOTF2-zoom.png
  1400   Fri Mar 13 19:26:09 2009 YoichiUpdateDMFseisBLRMS compiled

 I compiled seisBLRMS.

The tricks were the following:

(1) Don't add path in a deployed command.
It does not make sense to add paths in a compiled command because it may be moved to anywhere. Moreover, it can cause some weird side effects. Therefore, I enclosed the addpath part of mdv_config.m in a "if ~isdeployed ... end" clause to avoid adding paths when deployed. Instead of adding paths in the code, we have to add paths to necessary files with -I options at the compilation time. This way, mcc will add all the necessary files into the CTF archive.

(2) Add mex files to the CTF archive by -a options.
For some reason, mcc does not add necessary mex files into the CTF archive even though those files are called in the m-file which is being compiled. We have to add those files by -a options.

(3) NDS_GetData() is slow for nodus when compiled.
NDS_GetData(), which is called by get_data() stops for a few minutes when using nodus as an NDS server.
This problem does not happen when not compiled. I don't know the reason. To avoid this, I modified seisBLRMS.m so that when an environmental variable $NDS is defined, it will use an NDS server defined in this variable.

I wrote a Makefile to compile seisBLRMS. You can read the file to see the details of the tricks.
I also wrote a script start_seisBLRMS, which can be found in /cvs/cds/caltech/apps/DMF/compiled_matlab/seisblrms/. To start seisBLRMS, you can just call this script.
At this moment, seisBLRMS is running on megatron. Let's see if it continues to run without crashing.

Quote:

The seisBLRMS has been running on megatron via an open terminal ssh'd into there from allegra with matlab running. This

is because I couldn't get the compiled matlab functionality to work.

Even so, this running script has been dying lately because of some bogus 'NDS' error. So for today I

have set the NDS server for mDV on megatron to be fb40m:8088 instead of nodus.ligo.caltech.edu. If this seems to fix the problem

I will make this permanent by putting in a case statement to check whether or not the mDV'ing machine is a 40m-martian or not.

  1401   Fri Mar 13 20:23:37 2009 YoichiUpdateLSCAO path transfer function with X-arm locked
I measured the AO path transfer function while the X-arm is locked with the POX PDH signal.
The POX-I signal was already connected to the input 1 of the CM board. So I injected a signal from the EXC-B channel of the board and measured the transfer function from TP2B to TP1A. To open the loop, I disabled the switch befor the EXC-B.
The attached plot shows the measured transfer function.
There is a bump around 2kHz, which can also be seen in the AO path TF posted in elog:1399, but not the large structure at around 3.8kHz.
The 3.8kHz structure is probably created by the feedback.
Attachment 1: AOPath-Xarm.png
AOPath-Xarm.png
ELOG V3.1.3-