Mostly a note to self:  I have put terminators on the ADC inputs which are usually the PEM-SEIS-GUR2_(XYZ) channels.  Since these 3 signals are currently going into the ASS ADC, these PEM ADC inputs are open, and have predefined channel names.  I'll collect the data and put it as the ADC noise level in my nifty plot which will show the noise limits of all things which affect Wiener Filtering.

 I've added the side coil to the model controller and plant, and the oplev quad to the model controller and plant.  After the megatron wipe, the code now lives in /home/controls/cds/advLigo/src/epics/simLink.  The files are mdc.mdl (controller) and mdp.mdl (plant).  These RCG modules go at 16K with no decimation (no_oversampling=1 in the cdsParameters block) so hopefully will work with the old (16K) timing.

I've loaded many of the filters, there are some eft to do.  These filters are simply copied from the current frontend.  

Next I will port to the SUS module (which talks to the IO chassis).  This means channel names will match with the current system, which will be important when we plug in the RFM.

RFAMPD_DCMON disappered on Nov 5, 2009

The attached plot shows the spectra of the 3 Z axes of the 3 seismometers we have (this data is from ~20Aug2009, when the Ranger was in the Z orientation) in Magenta, Cyan and Green, and the noise of each of the sensors in Red, Blue and Black.  The noise curves were extracted from the spectra using the Huddle Test / 3 Corner Hat method.  The Blue and Black traces which are just a few points are estimates of the noise from other spectra.  The Blue points come from the Guralp Spec Sheet, and the Black comes from the noise test that Rana and I did the other day with the Ranger (elog 2223).  

I'm not really happy with the black spectra - it looks way too high.  I'm still investigating to see if this is a problem with my calibration/method....

I've opened the AP table and I'm working on it.

I re-aligned the Faraday on the AP table. I also aligned the beam to the periscope on the PSL and all the other optics along the beam path.  Now I have a nice NPRO beam at the PLL which overlaps with the PSL beam. The alignment has to be further improved because I see no beat yet.

I wonder if the all the tinkering on the PSL laser done recently to revive the power has changed the PSL NPRO temperature and so its frequency. That could also explain why the beat doesn't show up at the same temperature of the NPRO as I used to operate it. Although I scanned the NPRO temperature +/- 2 deg and didn't see the beat. So maybe the misalignment is the casue.

Not feeling very well right now. I need to go home for a while.

AP table closed at the moment.

NPRO shutter closed

 We definitely changed the PSL NPRO temp while fiddling around, trying to increase the laser power.  I think it's noted in the elog both times that it's happened in the last few months (once when Rana, Koji and I worked on it, and then again when it was just Koji), but we opened up the side of the MOPA box so that we could get at (and change) the potentiometer which adjusts the NPRO temp.  So you may have to search around for a while.

Yes it did.

For long time, the crystal temperature C1:PSL-126MOPA_LTMP was 43~46deg. Now it is 34deg. Try ~10deg lower temperature.

The .mdl code for the mdc and mdp development modules is finished.  These modules need more filters, and testing.  Probably the most interesting piece left to do is putting in the gains and filters for the oplev model in mdp.  It might be OK to simply ignore oplevs and first test damping of the real optic without them.   However, it shouldn't be hard to get decent numbers for oplevs, add them to the mdp (plant) module, and make sure the mdc/mdp pair is stable.  In mdp, the oplev path starts with the SUSPIT and SUSYAW signals. Kakeru recently completed calibration of the oplevs from oplev cts to radians:   1403  .  From this work we should find the conversion factors from PIT and YAW to oplev counts, without making any new measurements.  (The measurements wouldn't be hard either, if we can't simply pull numbers from a document.)  These factors can be added to mdp as appropriate gains.

I've also copied mdc to a new module, which I've named "sas" to address fears of channel name collisions in the short term, and replaced the cpu-to-cpu connections with ADC and DAC connections.  sas can be the guy for the phase I ETMY test.  When we're happy with mdc/mdp, we hopefully can take the mdc filter file from chans, replace all the "MDC" strings with "SAS", and use it.

I have been working about multi-resonant EOM since last week.

In order to characterize the behavior of the each components, I have made a simple LC tank circuit.

You can see the picture of the circuit below.

Before constructing the circuit, I made an "ideal" calculation of the transfer function without any assumptions by my hand and pen.

Most difficult part in the calculation is the dealing with a transformer analytically. Eventually I found how to deal with it in the analytical calculation.

The comparison of the calculated and measured transfer function is attached.

 It shows the resonant frequency of ~50MHz as I expected. Those are nicely matched below 50MHz !!

For the next step, I will make the model of the circuit with stray capacitors, lead inductors, ... by changing the inductance or something. 

I have created a directory under the svn. The link is https://nodus.ligo.caltech.edu:30889/svn/trunk/docs/haixing

In the directory, there are three folders are related to the magnetic levitation.

The experimental data is in the "experiment_data".

The comsol numerical modelling files are in "mag_levi_comsol_modelling" which contains "1x1 magnets",

"4x4 magnets" and "16x16 magnets" sub-folders where detailed modelling results are included.The mathematica

notebooks in those folders are used to produce the plots I posted on the wiki page.

The "mag_levi_feedback" contains the Simulink modelling of the feedback loop. To generate the plot for the

open-loop transfer function. One needs to ruc the "mag_lev.m" file.

I built a Simulink model of the magnetic levitation system and try to explain the dip in the open-loop transfer function that was observed.

One can download the model in the svn. The corresponding block diagram is shown by the figure below.

Here "Magnet" is equal to inverse of the magnet mass. Integrator "1/s" gives the velocity of the magnet. A further integrator gives the displacement of the magnet.

Different from the free-mass response, the response of the magnet is modified due to the existence of the Eddy-current damping  and negative spring in the vertical

direction, as indicated by the feedback loops after two integrals respectively. The motion of the magnet will change the magnetic field strength which in turn will pick

up by the Hall-effect sensor. Unlike the usual case, here the Hall sensor also picks up the magnetic field created by the coil as indicated by the loop below the mechanical

part. This is actually the origin of the dip in the open-loop transfer function. In the figure below, we show the open-loop transfer function and its phase contributed by both

the mechanical motion of the magnet and the Hall sensor with the black curve "Total". The contribution from the mechanical motion alone is shown by the magenta curve

"Mech" which is obtained by disconnecting the Hall sensor loop (I rescale the total gain to fit the measurement data due to uncertainties in those gains indicated in the figure). 

The contribution from the Hall sensor alone is indicated by the blue curve "Hall" which  is obtained by disconnecting the mechanical motion loop. Those two contributions

have the different sign as shown by the phase plot, and they destructively interfere with each other and create the dip in the open-loop transfer function.

In the following figure, we show the close-loop response function of the mechanical motion of the magnet.

As we can see, even though the entire close loop of the circuit is stable, the mechanical motion is unstable around 10 Hz. This simply comes from the fact that

around this frequency, the Hall sensor almost has no response to the mechanical motion due to destructive interference as mentioned.

In the future, we will replace the Hall sensor with an optical one to get rid of this undesired destructive interference.

The concrete  floor cutting has begun next door at CES

This morning I found a frequency generator connected to something on the PSL table sitting on the blue step next to the sliding doors.

Is anyone using it? Has it been forgotten there? If that's the case, can the interested person please take care of removing it?

I've opened the AP table and I'm working on it.

Also auxiliary NPRO turned on and mechanical shutter opened.

Last night there was an activity for a calibratuon work, which I helped. I can take care of the FG.

 Beat found at 30MHz with auxiliary NPRO temperature of 37.19 degrees, vs. ~48 deg as it used to be.

The beat is small (-70dBm). PLL alignment has to be improved.

I added the StochMon calibrated channels to the data trend by including the following channel names in the C0EDCU.ini file:

[C1:IOO-RFAMPD_33MHZ_CAL]
[C1:IOO-RFAMPD_133MHZ_CAL]
[C1:IOO-RFAMPD_166MHZ_CAL]
[C1:IOO-RFAMPD_199MHZ_CAL]

Before saving the changes I committed C0EDCU.ini to the svn.

Then I restarted the frame builder so now the new channels can be monitored and trended.

We connected megatron to the IO chassis which in turn was plugged into the rest of the ITMY setup.  We had manually turned the watchdogs off before we touched anything, to ensure we didn't accidently drive the optic.  The connections seem to go smoothly.

However, on reboot of megatron with the IO chassis powered up, we were unable to actually start the code.  (The subsystem has been renamed from SAS to TST, short for test).  While starttst claimed to start the IOC Server, we couldn't find the process running, nor did the medm screens associated with it work.

As a sanity test, we tried running mdp, Peter's plant model, but even that didn't actually run.  Although it also gave an odd error we hadn't seen before:

"epicsThreadOnceOsd epicsMutexLock failed."

Running startmdp a second time didn't give the error message, but still no running code.  The mdp medm screens remained white.

We turned the IO chassis off and rebooted megatron, but we're still having the same problem.

Things to try tomorrow:

1) Try disconnecting megatron completely from the IO chassis and get it to a state identical to that of last night, when the mdp and mdc did run.

2) Confirm the .mdl files are still valid, and try rebuilding them

On Rana's suggestion I checked the MC transmission QPD (C1:IOO-MC_TRANS_SUM). I found that the readout is almost zero when the MC is unlocked.

I unlocked the Mode Cleaner turning off the LSC control and disabling the autolocker. The QPD reads 0.014. It seems that there is no offset.

I also checked with the IR card around the photodetector and I didn't see any stray beam.

 PLL alignment improved. Beat amplitude = -10dBm. Good enough.

DC readouts at the PLL photodiode:

V_NPRO = -4.44V

V_PSL = -3.76V

The NPRO beam is attenuated by a N.D.=1 attenuator just before going to the photodiode.

Something strange happened at the last. Right before -10dBm, the amplitude of the beat was about -33dBm. Then I was checking the two interfering beams with the IR card and saw that they overlapped quite well. I then turned my head back to the spectrum analyzer and suddenly the beat was at -10dBm. Not only, but a bunch of new peaks had appeared on the spectrum. Either I inadvertently hit the PD moving it to a better position or something else happened.

Like if someone was making some other modulation on the beam or the modulation depth of the PSL's sidebands had gone up.

OK. I have been keeping my eyes on the MC transmission. In deed, the MC trans has been well kept at around 7.7 since the last PSL work.
Even it was over the 8 today!

PC_DRIVE is also improving after the last PSL work!

I locked the PLL and made some first measuremtns of the spectrum of the error signal. I'll post them later.

I closed the shutter of the NPRO.

I have measured the impedance of the LC tank circuit which I referred on my last entry.

The configuration of the circuit is exactly the same as that time.

In order to observe the impedance, by using Koji's technique I injected a RF signal into the output of the resonant circuit.

In addition I left the input opened, therefore the measured impedance does not include the effect of the transformer.

- - - - - - - - - - - - results

The measured impedance is attached below; "LCtank_impedance.png"

The peak around 50MHz is the main resonance and it has impedance of ~1500 [Ohm], which should go to infinity in the ideal case (no losses).

In fact the impedance looked from the input of the circuit gets reduced by 1/n^2, where "n" is the turn ratio of the transformer.

By putting the n=4, the input impedance of the circuit should be 93 [Ohm]. This is a moderate value we can easily perform impedance-matching by some technique.

I also fitted the data with a standard model of equivalent circuit (see attachment 2).

In the figure.2 red component and red letter represents the design. All the other black stuff are parasites.

But right now I have no idea the fitted value is reasonable or not.

For the next I should check the input impedance again by the direct way; putting the signal into the input.

I measured the input impedance of the LC tank circuit with the transformer. The result is attached.

It looks interesting because the input impedance is almost dominated

by the primary coil of the transformer with inductance of 75nH (see attachment 1).

The impedance at the resonance is ~100 [Ohm], I think this number is quite reasonable because I expected that as 93 [Ohm]

Note that the input impedance can be derived as follower;

(input impedance) = L1 + Z/n^2.

Where L1 is the inductance of the primary coil, Z is the load in the secondary loop and n is the turn ratio.

I think now I am getting ready to enter the next phase \(^o^)/

Megatron's top fan, rear ps, and temperature front panel lights were all lit amber this morning.  I checked the service manual, found at :

http://docs.sun.com/app/docs/prod/sf.x4600m2?l=en&a=view

According to the manual, this means a front fan failed, a voltage event occured, and we hit a high temperature threshold.  However, there were no failure light on any of the individual front fans (which should have been the case given the front panel fan light).  The lights remained on after I shutdown megatron.  After unplugging, waiting 30 seconds, and replugging the power cords in, the lights went off and stayed off.  Megatron seems to come up fine.

I unplugged the IO chassis from megatron, rebooted, and tried to start Peter's plant model.  However, it still prints that its starting, but really doesn't.  One thing I forgot to mention in the previous elog on the matter, is that on the local monitor it prints "shm_open(): No such file or directory" every time we try to start one of these programs.

I called Alex this morning and explained the problems with megatron.

Turns out when he had been setting up megatron, he thought a startup script file, rc.local was missing in the /etc directory.  So he created it.  However, the rc.local file in the /etc directory is normally just a link to the /etc/rc.d/rc.local file.  So on startup (basically when we rebooted the machine yesterday), it was running an incorrect startup script file.  The real rc.local includes line:

/usr/bin/setup_shmem.rtl mdp mdc&

Hence the errors we were getting with shm_open().  We changed the file into a soft link, and resourced the rc.local script and mdp started right up.  So we're back to where we were 2 nights ago (although we do have an RFM card in hand).

Update:  The tst module wouldn't start, but after talking to Alex again, it seems that I need to add the module tst to the /usr/bin/setup_shmem.rtl mdp mdc& line in order for it to have a shared memory location setup for it.  I have edited the file (/etc/rc.d/rc.local), adding tst at the end of the line.  On reboot and running starttst, the code actually loads, although for the moment, I'm still getting blank white blocks on the medm screens.

I've placed some notes pertaining to what Koji and I have learned today about getting the RCG code working on the 40m wiki at:

http://lhocds.ligo-wa.caltech.edu:8000/40m/Notes_on_getting_the_CDS_Realtime_Code_Generator_working

We're still trying to fix the tst system, as the moment its reporting an invalid number of daq channels and during daq initialization it fails.  (This from the /cvs/cds/caltech/target/c1tst/log.txt file). Note: This problem is only on megatron and separated from the conventional DAQ system of the 40m.

cpu clock 2800014
Warning, could open `/rtl_mem_tst' read/write (errno=0)
configured to use 2 cards
Initializing PCI Modules
2 PCI cards found
***************************************************************************
1 ADC cards found
        ADC 0 is a GSC_16AI64SSA module
                Channels = 64
                Firmware Rev = 512

***************************************************************************
1 DAC cards found
        DAC 0 is a GSC_16AO16 module
                Channels = 16
                Filters = None
                Output Type = Differential
                Firmware Rev = 3

***************************************************************************
0 DIO cards found
***************************************************************************
0 IIRO-8 Isolated DIO cards found
***************************************************************************
0 IIRO-16 Isolated DIO cards found
***************************************************************************
0 Contec 32ch PCIe DO cards found
0 DO cards found
***************************************************************************
0 RFM cards found
***************************************************************************
Initializing space for daqLib buffers
Initializing Network
Found 1 frameBuilders on network
Waiting for EPICS BURT at 0.000000 and 0 ns 0x3c40c004
BURT Restore = 1
Waiting for Network connect to FB - 10
Reconn status = 0 1
Reconn Check = 0 1
Initialized servo control parameters.
DAQ Ex Min/Max = 1 32
DAQ Tp Min/Max = 10001 10094
DAQ XTp Min/Max = 10094 10144
DAQ buffer 0 is at 0x8819a020
DAQ buffer 1 is at 0x8839a020
daqLib DCU_ID = 10
DAQ DATA INFO is at 0x3e40f0a0
Invalid num daq chans = 0
DAQ init failed -- exiting

 Dmass tells me that you have to record at least one channel.  ie at least one channel in your .ini file must be set to acquire, otherwise the DAQ will flip out.  It seems to be unhappy when you're not asking it to do things.

I continued on the STAND ALONE debugging of the megatron codes.

- I succeeded to run c1aaa with ADC/DAC. (c1aaa is a play ground for debugging.)

  The trick was "copy DAC block from sam.mdl to aaa.mdl".
  I don't understand why this works. But it worked.
  I still have the problem of the matrices. Their medm screens are always blank. Needs more works.

- Also I don't understand why I can not run the build of c1tst when I copy the working aaa.mdl to tst.mdl.

- The problem Joe reported: "# of channels to be daqed" was solved by

make uninstall-daq-aaa
make install-daq-aaa



  This command is also useful.

daqconfig

- Now I am in the stable development loop with those commands

killaaa
make uninstall-daq-aaa
make aaa
make install-aaa
make install-daq-aaa
make install-screens-aaa
startaaa


  I have made "go_build" script under /home/controls/cds/advLigo

usage:
./go_build aaa

- Note for myself: frequently visited directories

/home/controls/cds/advLigo/src/epics/simLink (for model)
/home/controls/cds/advLigo (to build)
/cvs/cds/caltech/target/c1aaa (realtime code log)
/cvs/cds/caltech/target/c1aaaepics (ioc log)
/cvs/cds/caltech/medm/c1/aaa (medm screens)
/cvs/cds/caltech/chans (filter coeffs)
/cvs/cds/caltech/chans/daq (daq settings)

I am still working on the c1aaa code. Now it seems that C1AAA is working reasonably (...so far).

1) At a certain point I wanted clean up the system status. I have visited /etc/rc.local to add c1aaa for realtime to non-realtime task

before:
/usr/bin/setup_shmem.rtl mdp mdc tst&
after:
/usr/bin/setup_shmem.rtl mdp mdc tst aaa&


   I rebooted the system several times.

sudo /sbin/reboot

2) I found that gabage medm screens accumulated in ~/cds/advLigo/build/aaaepics/medm after many trials with several simulink models.
This directory is always copied to /cvs/cds/caltech/medm/c1/aaa at every make install-screens-aaa
This caused very confusing MEDM screens in the medm dir like C1AAA_ETMX_IN_MATRX.adl (NOT ETMY!)

I did

cd ~/cds/advLigo
make clean-aaa


to refresh aaaepics dir. The current development procedure is

killaaa
make clean-aaa
make uninstall-daq-aaa
make aaa
make install-aaa
make install-daq-aaa
make install-screens-aaa
startaaa

3) Sometimes startaaa does not start the task properly. If the task does not work, don't abandon.
Try restart the task. This may help. 

killaaa
(deep breathing several times)
startaaa

What to do next:

- MEDM works

* make more convenient custom MEDM screens so that we can easily access to the filters and switches
* retrofit the conventional SUS MEDM to the new system

- once again put/confirm the filter coeffs and the matrix elements

- configure DAQ setting so that we can observe suspension motion by dataviewer / dtt

- connect the suspension to megatron again

- test the control loop

This afternoon, I tried to lock the interferometer again after a few days.

After a couple of failed attempts, and relocks of the MZ, the interferometer stayed locked continuously for about 50 minutes, with arm power of about 92.

I just wanted to check the status of the interferometer so I didn't do any particular measurement in the meantime.

ATM1: Seismometers are saturating, suspensions are OK

Atm2 : activity next door,  diesel Backhoe and diesel concrete cutter are running

Atm3: CES exhaust fans output  is pick up by 40M-Annex-North AC unit  intake. The 40m office room has some diesel smell...........see # 2377

In order to get the gige camera code running robustly here at the 40m, I created a "Yoichi style" ezcaread, which is now the default, while the original ezcaread is located in ezcaread.bin.  This tries 5 times before failing out of a read attempt.

By including a differentiator from 10 Hz to 50 Hz, we increase the phase margin and the resulting

magnetic levitation system is stable even without the help of eddy-current damping.

The new block diagram for the system is the following:

Here the eddy-current damping component is removed and we add an additional differential

circuit with an operational amplifier OP27G.

In addition, we place the Hall sensor below the magnet to minimize the coupling between

the coil and the Hall sensor.

The resulting levitation system is shown by the figure below:

An interesting thing was happened in the OMC-LSC timing clock.

Right now the clock of the OMC and the LSC are completely synchronized.

 The trend data is shown below. At the first two measurements (Oct.27 and Nov.1),  LSC had constant retarded time of 3Ts (~92usec.).

The last measurement, on Nov.15, number of shifts goes to zero, this means there are no retarded time.

Also the variance between the two signal gets zero, so I conclude the OMC and the LSC are now completely synchronized.

The measurement on Nov.8 is somehow meaningless, I guess the measurement did not run correctly by an influence from megatron(?)

Dmass, Joe, Koji

A puzzle has been solved: Dmass gave us a great tip

"The RGC code does not work unless the name of the mdl file (simulink model) matches to the model name "

The model name is written in the second line. This is automatically modified if the mdl file is saved from simulink.
But we copied the model by using "cp" command. This prevent from the TST model working!

megatron:simLink>head tst.mdl
Model {
  Name                    "tst"
  Version                 7.3
  MdlSubVersion           0
...
...
...

This explained why the AAA model worked when the DAC block has been copied from the other model.
This was not because of the ADC block but the saving model fixed the model name mismatch!

Now our current working model is "C1TST". Most of the functionalities have been implemented now:

• The simulink model has been modified so that some of the functionalities can be accomodated, such as LSC/ASC PIT/ASC YAW.
• Some filter names are fixed so as to inherit the previous naming conventions.
• The SUS-ETMY epics screen was modified to fit to the new channel names, the filter topologies, and the matrices.
• The chans file was constructed so that the conventional filter coefficients are inherited.
• All of the gains, filter SWs, matrix elements have been set accordingly to the current ETMY settings.
• burt snapshot has been taken: /cvs/cds/caltech/target/c1tstepics/controls_1091117_024223_0.snap
burtrb -f /cvs/cds/caltech/target/c1tstepics/autoBurt.req -o controls_1091117_024223_0.snap -l /tmp/controls_1091117_024215_0.read.log -v

What to do next:

• Revisit Oplev model so that it accomodates a power normalization functionality.
• ETMY QPD model is also missing!
• Clean up mdl file using subsystem grouping

• Check consistency of the whitening/dewhitening switches.
• Connect ADC/DAC to megatron
• Test of the controllability
• BTW, what is happened to BIO?
• Implementation of the RFM card

Directories and the files:

• The .mdl file is backed up as
/home/controls/cds/advLigo/src/epics/simLink/tst.mdl.20091116_2100


• The default screens built by "make" is installed in
  /cvs/cds/caltech/medm/c1/tst/
They are continuously overridden by the further building of the models.


• The custom-built medm screens are stored in
/cvs/cds/caltech/medm/c1/tst/CustomAdls/

The backup is
/cvs/cds/caltech/medm/c1/tst/CustomAdls/CustomAdls.111609_2300/


• The custom-built chans file is
/cvs/cds/caltech/chans/C1TST.txt

The backup is
/cvs/cds/caltech/chans/C1TST.111609


• burt snap shot file
  /cvs/cds/caltech/target/c1tstepics/controls_1091117_024223_0.snap


The smell of diesel is particularly bad this morning.  Its concentrated enough to be causing me a headache.  I'm heading off to Millikan and will be working remotely on Megatron.

[Rana, Jenne]

We opened up the little Thorlabs battery operated PD to see what was inside.  Rana took some pictures, and I drew a schematic (attached).  It's just a diode, biased with a battery (albeit a crazy 22.5V battery).

---------------
Comment by KA: PD is Hamamatsu S1223-01 Si PIN diode.

What a crazy battery. The main point is that it looks like this can be used for reasonable purposes: uses a load resistor on the BNC connector and you can use some pre-amp (e.g. Busby box or SR560) to have a low noise PD readout. You can also use the SR560 in its A-B mode as an 'opamp'. Ground the A input and the use a pole at 1 Hz and make the Output go into the B input through some large series resistor. The BNC from the PD gets Teed into the B input as well.

Then this becomes a transimpedance circuit readout of the diode, using the current noise of the SR560 as the limit.

Had been disconnected for about two weeks.  I found a partially seated 4-pin LEMO cable coming from the OSEM PD interface board. 

The circuit design of multi-resonant EOM have proceeded.

By using numerical method, I found the some best choice of the parameters (capacitors and inductors).

In fact there are 6 parameters (Lp, L1, L2, Cp, C1, C2) in the circuit to be determined.

In general the less parameter gives the less calculation time with performing the numerical analysis. Of course it looks 6 parameters are little bit large number.

In order to reduce the arbitrary parameters, I put 4 boundary conditions.

Each boundary conditions fixed resonant peaks and valleys; first peak=11MHz, third peak=55MHz, first valley=19MHz, second valley=44MHz.

So now the remaining arbitrary parameters successfully get reduced to 2. Only we have to do is optimize the second peak as it to be 29.5MHz.

Then I take C1 and C2 as free parameters seeing how the second peak agree with 29.5MHz by changing the value of the C1 and C2.

the red color represents the good agreement with 29.5MHz, in contrast blue contour represents the bad.

 You can see some best choice along the yellow belt. Now what we should do is to examine some of that and to select one of those.

In designing the whole circuit it is better to know the characteristic of the EOM.

I made impedance measurement with the EOM (New Focus model 4064) and I found it has capacitance of 10pF.

This is good agreement with the data sheet which says "5-10pF".

The measured plot is attached below. For comparison there also plotted "open" and "10pF mica".

In the interested band( from 1MHz to 100MHz), EOM looks just a capacitor.

But indeed it has lead inductance of 12nH, resistance of 0.74[Ohm], and parasitic capacitance of 5.5pF.

In some case we have to take account of those parasites in designing.

How can I get those values from the figure?

I added ~500 cc of distilled water to the laser chiller yesterday.

8 days plot: Thurdsay, Friday, Sat and Sun without construction

This is a continuation from last night, where Peter, Koji, and I were trying to get test point channels working on megatron and with the TST module.

Things we noticed last night:

We could run starttst, and ./daqd -c daqdrc, which allowed us to get some channels in dataviewer.  The default 1k channel selection works, but none of the testpoints do. 

However, awgtpman -s tst does appear in the processes running list.

The error we get from dataviewer is:

Server error 861: unable to create thread
Server error 23328: unknown error
datasrv: DataWriteRealtime failed: daq_send: Illegal seek

Going to DTT, it starts with no errors in this configuration.  Initially it listed both MDC and TST channels.  However, as a test, I moved the tpchn_C4.par , tpchn_M4.par and tpchn_M5.par files to the directory backup, in /cvs/cds/caltech/target/gds/param.  This caused only the TST channels to show up (which is what we want when not running the mdc module.

We had changed the daqdrc file in /cvs/cds/caltech/target/fb, several times to get to this state.  According to the directions in the RCG manual written by Rolf, we're supposed to "set cit_40m=1" in the daqdrc file, but it was commented out.  However, when we uncommented it, it started causing errors on dtt startup, so we put it back.  We also tried adding lines:

set dcu_rate 13 = 16384;
set dcu_rate 14 = 16384;

But this didn't seem to help.  The reason we did this is we noticed dcuid = 13 and dcuid = 14 in the /cvs/cds/caltech/target/gds/param/tpchn_C1.par file.  We also edited the testpoint.par file so that it correctly corresponded to the tst module, and not the mdc and mdp modules.  We basically set:

[C-node1]
hostname=192.168.1.2
system=tst

in that file, and commented everything else out.

At this point, given all the things we've changed, I'm going to try a rebuild of the tst and daq and see if that solves things.

I did a full make clean and make uninstall-daq-tst, then rebuilt it.  I copied a good version of filters to C1TST.txt in /cvs/cds/caltech/chans/ as well as a good copy of screens to /cvs/cds/caltech/medm/c1/tst/.

Test points still appear to be broken.  Although for a single measurement in dtt, I was somehow able to start, although the output in the results page didn't seem to have any actual data in the plots, so I'm not sure what happened there - after that it just said unable to select test points.  It now says that when starting up as well.  The tst channels are the only ones showing up.  However, the 1k channels seem to have disappeared from Data Viewer, and now only 16k channels are selectable, but they don't actually work.  I'm not actually sure where the 1k channels were coming from earlier now that I think about it.  They were listed like C1:TST-ETMY-SENSOR_UL and so forth.

RA: Koji and I added the SENSOR channels by hand to the .ini file last night so that we could have data stored in the frames ala c1susvme1, etc.