 Wed Dec 20 00:43:58 2017, Kevin, Summary, General, DAC noise contribution to squeezing noise budget 
|
Gautam and I looked into the DAC noise contribution to the noise budget for homodyne detection at the 40m. DAC noise is currently the most likely limiting
source of technical noise.
Several of us have previously looked into the optimal SRC detuning and homodyne angle to observe pondermotive squeezing at the 40m. The first |
 Thu Dec 21 19:25:48 2017, Kevin, Summary, General, DAC noise contribution to squeezing noise budget
|
Gautam and I redid our calculations, and the updated plot of squeezing as a function of DAC current noise per coil is shown in the attachment. The current
noise is calculated as the maximum of the filtered DAC noise and the Johnson noise of the series resistor. The total noise is for four optics with four
coils each. |
|
Fri Dec 22 09:40:19 2017, rana, Summary, General, DAC noise contribution to squeezing noise budget
|
Should not count the ITMs. On those we can use big resistors / filters to cut out the noise.
For the initial LIGO, we used 7 K resistors
and the mass was 10 kg. But...the output driver went +/- 150 V.
So we had a max F/m = (20 mA * 0.064 N/A)/(10 kg) = 0.0001. For the 40m,
to get the same thing, we would need 40x less current (~0.5 mA). At the moment we have (12 V / 400 Ohm) = 30 mA. |
|
Mon May 22 13:37:01 2017, gautam, Update, General, DAC noise estimate
|
Summary:
I've spent
the last week investigating various parts of the DAC -> OSEM coil signal chain in order to add these noises to the MICH NB. Here is what I have thus
far. |
|
Fri Sep 22 18:12:27 2017, gautam, Update, LSC, DAC noise measurement (again)
|
I've been working on setting up some scripts for measuring the DAC noise.
In all the DRMI noise budgets I've posted, the coil-driver noise contribution has been based on this
measurement, which could be improved in a couple of ways: |
|
Wed Sep 27 22:25:21 2017, gautam, Update, LSC, DAC noise measurement (again)
|
Attachment #1: Summary of results of measurements made
on Friday. There is a lot in this plot, here is a breakdown:
I drove the excitation points of the coil output filter banks with raw time-series data downloaded during a DRMI lock with |
|
Thu Sep 28 06:35:44 2017, Chris, Update, LSC, DAC noise measurement (again)
|
Since you're monitoring two channels simultaneously, you could try subtracting them, as an alternative to carving out bandstops.
Drive both channels with the same time series
Tweak the filter module gains if needed to equalize the analog outputs
Apply
SR785 user math to subtract the two channels (or A-B mode of a single input, if you're not using that already?)
Measure the residual, which |
|
Thu Sep 28 23:50:04 2017, gautam, Update, LSC, DAC noise measurement (again)
|
I am running some more measurements of the DAC noise, for which I've shut down the BS watchdog. Some
of the cables on the coil driver side have been disconnected.
I will restore these tomorrow.
As Rana pointed
out to me, one important fact to keep in mind w.r.t. DAC noise is that it can be |
|
Fri Sep 29 18:36:25 2017, gautam, Update, LSC, DAC noise measurement (again)
|
BS connections and damping restored.
Quote:
I |
|
Tue Jul 30 19:40:47 2013, gautam, Configuration, endtable upgrade, DAC-PZT Driver Board Output Signal Chain Tested
|
[Alex, Gautam]
The signal chain from the DAC output to the output of the PZT driver |
|
Tue Aug 17 02:07:11 2010, Yoichi, Update, CDS, DACs have correct number of channels
|
Quote:
|
|
Mon Jun 13 20:01:30 2016, varun, Update, CDS, DAFI GUI update
|
Summary: I am implementing digital audio filtering on various interferometer signals in order to listen to the processed audio which
will help in characterizing and noise reduction in the interferometer. following is a summary of the gui i have made towards a general purpose DAF module
linked to the LSC. |
|
Tue Jun 14 20:10:19 2016, varun, Update, CDS, DAFI GUI update
|
I have added Enable buttons for each of the DSP blocks, and labels for the matrix elements. The input matrix takes inputs from each of the 4 channels:
ADC1, ADC2, LSC and EXC, and routes them to the audio processing blocks (attachment 2). The output matrix (attachment
3) takes the outputs of the various DSP blocks and routes them to the output and then to the speakers. |
|
Thu Jul 21 15:03:13 2016, varun, Update, CDS, DAFI Update
|
1) I have added the status summary of the DAFI block to the main FE status overview screen in the c1lsc cloumn. (attachment 1)
2) I have edited all the kissel matrix buttons appropriately, and given them appropriate lables. (attachment 2) |
|
Mon Aug 1 20:09:37 2016, rana, Update, CDS, DAFI Update
|
I found the DAFI screen as a button inside of the LSC screen - I think its more logically found from the sitemap, so I'll move it into there as well.
Quote:
1) I have added the status |
|
Thu Jul 21 14:27:24 2016, varun, Update, CDS, DAFI Update: Arbitrary Math block
|
Summary: I have added an arbitrary math block to the DAFI model, which takes two inputs, say X and Y, and can perform various unary
and binary operations on them:
Details: |
|
Sun Jul 10 20:08:44 2016, varun, Update, CDS, DAFI Update: Changes in LSC and PEM models
|
I have added the PEM signals mentioned in the previous elog as DAF inputs through PCIE IPC, and compiled and restarted the c1pem and c1daf models.
Attached are the pictures of the simulink diagram of the addition in the PEM and the DAF.
Since the signals are moving from a 2kHz clock rate machine to a 16kHz clock rate machine, some imaging effects are possible, which I have to |
|
Fri Jul 8 22:26:03 2016, varun, Update, CDS, DAFI Update: Changes in LSC model
|
I have added the control signals DARM_CTRL, MICH_CTRL, PRCL_CTRL, SRCL_CTRL, CARM_CTRL, XARM_CTRL, YARM_CTRL, MC_CTRL to the DAFI model from the
LSC model via IPC commn.
The changes done to the LSC model include addition of an extra block going to DAFI (attachment 2, red rectangle in attachment 1), and addition |
|
Wed Jul 6 10:58:29 2016, Varun, Update, CDS, DAFI review
|
The DAFI block was reviewed by Rana yesterday. The following changes/improvements were suggested: (Updated on 20th July 2016 with tasks
taat remain in red)
1) include all the various channels like PEM, LSC, ASC, SUS, SEI, etc. as the inputs. Currently the inputs are only the LSC. |
|
Fri Dec 6 15:22:01 2019, gautam, Frogs, LSC, DAFI system revived
|
[Jordan, gautam]
We did the following:
Route the fiber from the control room to 1Y2.
Plug fiber in to FiBox at either end, turned FiBoxes ON.
Tested the |
|
Fri Jun 3 17:56:14 2016, Varun, Update, General, DAFI update
|
Wrote and tested a phase vocoder, with two of its applications:
1) Time scaling: This enables change of time duration without affecting the pitch.
2) Frequency warping: This changes the pitch of the sound without affecting the time duration. |
|
Tue Jun 7 18:20:18 2016, Varun, Update, General, DAFI update
|
Tried to implement AGC on FE. Had some trouble bringing the code into the correct form. It looks okay now. However, this agc code as well as idenntity
code (input = output) doesnt seem to build on the c1lsc FE. Have not tried too many debugging steps yet, will come and check the problem tomorrow.
-Varun |
|
Wed Jun 8 16:12:38 2016, Varun, Update, General, DAFI update
|
Summary: I am implementing digital audio filtering on various interferometer
signals in order to listen to the processed audio which will help in characterizing and noise reduction in the interferometer. Following is
an implementation of an Automatic Gain control (AGC) block on an LSC input signal. |
|
Thu Jul 7 12:44:52 2016, varun, Update, CDS, DAFI update
|
Attached is a diagram, showing the entire (planned) signal flow of the DAF model. Some thoughts on the implementation after discussion with eric:
1) Since the LSC control signals and ASC signals are running on the c1lsc FE at the same rate as DAFI (16kHz), it would be wise to start from
these. |
|
Thu Jul 21 22:02:35 2016, varun, Update, CDS, DAFI update: Frequency warping
|
The code for frequency warping contained a "printf()" command, which had caused the system to crash in one another instance (refer elog
12320) . Hence, I tried running the code tody by removing this line. Unfortunately, this did not work. the model still crashed. Attached is the screenshot
of the FE status. |
|
Sat Jul 16 00:30:42 2016, varun, Update, CDS, DAFI update: Frequency warping | c1lsc unresponsive
|
Summary: I am trying to implement frequency warping/pitch shifting on the real time FE. Here is a description long overdue:
Description: The overall idea is as follows:
The DFT of a frame is given by |
|
Thu Jul 21 12:03:35 2016, varun, Update, CDS, DAFI update: Humming noise in DAFI output
|
Summary: There
was always a constant humming noise in the output of speakers of both the audio channels. Tried to resolve the problem. Details are given below: |
|
Wed Jun 15 22:12:55 2016, varun, Update, CDS, DAFI update: stereo output
|
I wish to have stereo audio output for the DAF module. Hence, there needs to be a second output from the DAF. I added this second output to the model.
Following are the details:
FiBox: It consists of two analog inputs which are digitized and multiplexed and transmitted optically. (only 1 fiber is needed |
|
Wed Jun 22 10:15:45 2016, varun, Update, CDS, DAFI update: stereo output
|
I have updated the DAFI with the following changes:
1) Separated both the channels of stereo output completely, as well as in the GUI.
2) Added text monitors for the inputs and outputs. |
|
Mon Jun 27 15:12:09 2016, varun, Update, CDS, DAFI update: stereo output
|
Using an RC to BNC connector from the inner drawer, I have added a second output cable going from the output Fibox in the control room to the audio mixer.
Quote:
I have updated the DAFI |
|
Fri Aug 7 14:31:39 2009, Alberto, Update, PSL, DAQ REstarted
|
| For some reason a few minutes ago the FB DAQ crashed and I had to restarted. |
|
Fri Jan 21 23:17:54 2011, rana, HowTo, DAQ, DAQ Wiki Failure
|
The DAQ Wiki pages say to use port 8088 for restarting the Frame Builder. I tried this to no avail.
op440m:daq>telnet fb 8088Trying 192.168.113.202... |
|
Mon Jan 24 10:39:16 2011, josephb, HowTo, DAQ, DAQ Wiki Failure
|
Actually both port 8087 and 8088 work to talk to the frame builder. Don't let the lack of a daqd prompt fool you.
Here's putting in the commands: |
|
Thu May 19 19:41:17 2011, Suresh, Update, RF System, DAQ channel Assignments for RF PDs
|
[Kiwamu, Suresh]
In trying to keep the wiring of the LSC rack as neat as possible, we came up with the following channel assignments of the RF PD signals.
|
|
Mon Oct 25 20:20:59 2010, yuta, Joe, Update, CDS, DAQ channel number etc
|
[U][B]Summary:[/B][/U]
We split the old SDSEN filters to SDSEN, SDSIDE, SDCOIL last week.
Along with this change, the TP channel number changed unfortunately.
|
|
Fri May 28 00:40:53 2010, rana, Update, PEM, DAQ down
|
Although trends are available, I am unable to get any full data from in the past (using DTT or DV). I started the FB's daqd process a few times,
but no luck.
I blame Joe's SimPlant monkeying from earlier today for lack of a better candidate. I checked and the frames are actually on the FB disk, so its |
|
Fri May 28 10:44:47 2010, josephb, Update, PEM, DAQ down
|
Quote:
Although trends are available, I am unable to get any full data from in the past (using DTT or DV). I started |
|
Tue Jun 8 18:39:36 2010, rana, Update, PEM, DAQ down
|
As before,
I am unable to get data from the past. With DTT on Allegra I got data from now, but its unavailable from 1 hour ago. Same problem using mDV on mafalda. |
|
Fri Mar 9 20:44:24 2012, Jim Lough, Update, CDS, DAQ restart with new ini file
|
DAQ reload/restart was performed at about 1315 PST today. The previous ini file was backed up as c1pem20120309.ini
in the /chans/daq/working_backups/ directory.
I set the following to record: |
|
Tue Mar 13 13:28:31 2012, Ryan Fisher, Update, CDS, DAQ restart with new ini file
|
Extra note: This was the ini file that was edited:
/cvs/cds/rtcds/caltech/c1/chans/daq/C1PEM.ini |
|
Thu Apr 21 10:35:23 2022, Koji, Update, CDS, DAQ seemed down
|
Yesterday, when I worked on the damping servo, I found that any of the daqvtools (ndscope, dtt, dataviewer,...) is not available. We may need to
restart the fb and rt machines. |
|
Thu Jan 20 00:39:22 2011, kiwamu, HowTo, CDS, DAQ setup : another trick
|
Here is another trick for the DAQ setup when you add a DAQ channel associated with a new front end code.
Once you finish setting up the things properly according to this wiki page (this |
|
Mon Apr 25 17:24:06 2022, Anchal, Update, CDS, DAQ still down
|
I investigated this issue today. At first, it seemed that only new suspension testpoints are inaccessible. I was able to use diaggui for a measurement
on MC2. The DAQ network cable between 1X4 and 1Y1 was tied and is very taught now (we should relieve this as soon as possible, best solution is to lay
down a longer cable over the bridge). My hypothesis is that the DAQ network might have broken while tying this cable and it probably did not come back |
|
Thu Sep 30 21:55:31 2010, rana, Update, CDS, DAQ sys update
|
Its pretty exciting to see that Joe got Alex to actually use the ELOG. Its a proof that even rare events occur if you are patient enough.
1) I fixed the MEDM links to point to the new sitemap.adl in /opt/rtcds. There is a link on the new sitemap which points to the old sitemap so
that there is nothing destroyed yet. |
|
Thu Sep 30 17:11:01 2010, alex i, Update, CDS, DAQ system update
|
The frame builder is timed from the Symmetricom GPS card now, which is getting the IRIGB timecode from the freq. distribution amplifier (from the VME
GPS receiver card).
I have adjusted the GPS seconds to match the real GPS time and the DTT seems to be happy: sweeping MC2 MCL filter module produces nice plot. |
|
Mon Jul 19 21:47:36 2010, rana, Summary, DAQ, DAQ timing test
|
Since we now have a good measurement of the phase noise of the Rb clock Marconi locked to the Rb clock, I wanted to use that to check
out the old DAQ system:
I used Megan's phase noise setup - Marconi #2 is putting out 11000013 Hz at 13 dBm into the ZP-3MH mixer. Marconi #1 is putting out 3 dBm at 11000000 |
|
Tue Jul 27 16:03:36 2010, rana, Summary, DAQ, DAQ timing test
|
Quote:
Since we now have a good measurement of the phase noise of the Rb clock |
|
Sat May 14 08:36:03 2022, Chris, Update, DAQ, DAQ troubleshooting
|
I heard a rumor about a DAQ problem at the 40m.
To investigate, I tried retrieving data from some channels under C1:SUS-AS1 on the c1sus2 front end. DQ channels worked fine, testpoint channels
did not. This pointed to an issue involving the communication with awgtpman. However, AWG excitations did work. So the issue seemed to be specific to the |
|
Mon May 16 10:49:01 2022, Anchal, Update, DAQ, DAQ troubleshooting
|
[Anchal, Paco, JC]
Thanks Chris for the fix. We are able to access the testpoints now but we started facing another issue this morning, not sure how it is related
to what you did. |
|
Mon May 16 12:59:27 2022, Chris, Update, DAQ, DAQ troubleshooting
|
It looks like the RFM problem started a little after 2am on Saturday morning (attachment 1). It’s subsequent to what I did, but during a time of
no apparent activity, either by me or others.
The pattern of errors on c1rfm (attachment 2) looks very much like this one previously |