ID |
Date |
Author |
Type |
Category |
Subject |
7817
|
Wed Dec 12 17:26:47 2012 |
Riju | Update | | Testing AG4395A+GPIB |
I repeated my experiment to get noise level. To get that I disconnected the bandpass filter SBP-10.7 from channel A of network analyzer AG4395A and terminated both the open ends (open end of filter and open end of channel A) with 50ohm terminator.
Reference level had been corrected, signal and noise data had been collected separately w.r.t that level.
Command for GPIB: ./netgpibdata.py -i 192.168.113.105 -d AG4395A -a 10 -f filename
The result is as follows
|
7834
|
Fri Dec 14 14:40:31 2012 |
Riju | Update | | Photodiode transimpedance |
Photodiode PDA10CF was under test. The RF out signal of AG4395A had been divided by splitter with one output of the splitter going to R channel of the network analyzer and the other to the laser. The splitted laser beams - splitted with beam splitter - fall on two photodiodes - one reference and the other on PDA10CF. The outputs of these two photodiodes go to channel B and A respectively of the network analyzer. The measured transimpedance data had been collected using the GPIB connection.
The result is as follows: |
7870
|
Fri Dec 21 19:49:39 2012 |
Riju | Update | | Photodiode transimpedance |
I have repeated the transimpedance measurement of PDA10CF. Also made the dark current noise measurement by connecting the PDA10CF output to the A channel of network analyzer. The results are as follows. I I started to take the reading for shot noise intercept current using a light bulb in front of the PD, changing the current through the bulb, but at higher current the bulb filament got broken, so the experiment is incomplete. |
7874
|
Thu Jan 3 20:34:43 2013 |
Riju | Update | | Photodiode transimpedance |
Today I have measured the transimpedance and dark-noise of the MC-REFL PD.
For transimpedance measurement I first collected the data of the reference Newfocus PD connecting it at channel B of Network-analyzer using the set-up of Jenne's laser. The data for the MC-REFL PD had been collected by connecting it to the A channel of Network Analyzer. To do that I shifted the Jenne's Laser to the table of MC-REFL PD, I moved the laser output on the table and fixed a lens and a mirror on the table. Taking the ratio of the two sets of datas I got the required trans-impedance.
Dark-noise readings were taken keeping the laser off.
I will upload the corresponding plots tomorrow. |
7880
|
Tue Jan 8 14:01:21 2013 |
Riju | Update | | Photodiode transimpedance |
Here I upload the plots corresponding to my last day's measurements.
|
7881
|
Tue Jan 8 14:07:04 2013 |
Riju | Update | Electronics | Photodiode transimpedance |
Quote: |
You have to correct this transimpedance ratio by correcting for the different levels of DC photocurrent in the two devices.
For the dark noise, you must always include a trace showing the noise of the measurements device (i.e. the analyzer noise must be less than the dark PD noise) with the same input attenuation setting.
|
Hi,
The correction for different levels of DC photocurrent in the two devices had been taken care by one MATLAB code, the code that originally was made by Koji.
The analyzer noise I had not recorded; today I am going to record it.
Riju |
7882
|
Tue Jan 8 15:28:41 2013 |
Riju | Update | Electronics | Photodiode transimpedance |
Quote: |
Quote: |
You have to correct this transimpedance ratio by correcting for the different levels of DC photocurrent in the two devices.
For the dark noise, you must always include a trace showing the noise of the measurements device (i.e. the analyzer noise must be less than the dark PD noise) with the same input attenuation setting.
|
Hi,
The correction for different levels of DC photocurrent in the two devices had been taken care by one MATLAB code, the code that originally was made by Koji.
The analyzer noise I had not recorded; today I am going to record it.
Riju
|
Here is the data for AG4395A network/spectrum analyzer noise data. I collected the data by putting 50ohm terminator on channel A with same input attenuation setting (0dB attenuation). |
7887
|
Wed Jan 9 19:32:24 2013 |
Riju | Update | | Photodiode transimpedance |
Summary:
Today I have tested the MC transmission-end RF photodiode PDA255 for transimpedance and dark noise using Jenne's Laser and AG4395A network/spectrum analyzer. The dark noise voltage distribution for the transmission and reflection PDs of MC and the analyzer has been compared.
Motivation:
I am to do the input mode cleaner cavity mode scan. The electronic and shot noise of the components used , particularly photodiode noise, will affect the peak position of the modes, indicating the uncertainty in the measured frequencies of the modes. That will in turn give the uncertainty in the measured change of radius of curvature of the mirrors in presence of the laser beam, from which we will be able to calculate the uncertainty in the mirror-absorption value.
Method:
For PD transimpedance measurement I used Jenne's laser along with AG4395 network analyzer. The RF out signal of AG4395A had been divided by splitter with one output of the splitter going to R channel of the network analyzer and the other to the laser. The splitted laser beams - splitted with beam splitter - fall on two photodiodes - one reference(Newfocus1617? PD, the DC and RF transimpedance values were taken from its datasheet ) and the other on PDA255. The outputs of these two photodiodes go to channel B and A respectively of the network analyzer. The measured transimpedance data had been collected using the GPIB connection. It had been ensured that the PD under test is not going to saturation, for that the source power level was kept to -40dBm. transimpedance measurements were compensated by the ratio of DC photocurrent.
For dark noise measurement the output of the PD was connected to the A channel of the AG4395A, when there was no light falling on it. The response is collected using GPIB. The attenuation of channel A was made 0dB. ( AG4395A was kept in Spectrum analyzer mode in Noise Format).
Results:
The plots corresponding to the measurements are attached.
Discussion:
The comparison for the dark noise voltage levels of the MC transmission PD (PDA255) with MC REFL PD has been made with analyzer dark noise voltage. It is shown in the attachment (I will upload the dark noise current comparison too....since the output darknoise depends on the gain of the circuit, it is important to divide this voltage spectra by transimpedances.) |
7907
|
Wed Jan 16 18:58:08 2013 |
Riju | Update | | Photodiode transimpedance |
Today I have taken the reading for shot noise intercept current for the PDA255 - MC transmission RF PD. To do that I have put an incandescent bulb (JKL lamps, 222 bulbs, voltage and current rating 2.25V and 0.25A) in front of the PD and varied the current through it from 0A to 0.29A at 2.2V. I measured the corresponding DC voltage and took the noise data (4395A spectrum analyzer/ format noise, channel attenuation 0dB) through GPIB .
I will process the data and upload the result soon. |
7926
|
Tue Jan 22 17:29:29 2013 |
Riju | Update | | Photodiode transimpedance |
Riju
Summary: I am stuck with the measurement of shot-noise-intercept-current of PDA255. Seeking help.
Motivation: It is to measure the shot noise intercept current for PDA255 - the MC transmission RF photodiode to get an idea for the noise current for the detector.
Method: It is as described in the elog 7907
Result: The plot is attached here.
Discussion: The result I got is really unexpected, the noise voltage should increase with the DC current level that corresponds to the increment of light level too. But actually it is decreasing. Three times I have repeated this experiment and got the same result. I want some suggestion on this regard. |
7929
|
Wed Jan 23 11:43:19 2013 |
Riju | Update | | Photodiode transimpedance |
Quote: |
- The data should be plotted in a log-log scale.
- The data points were only taken in the high current region.
- The plot may suggest that the amplifier saturate at the RF.
PDA255 has the nomial transimpedance gain of 10^4 Ohm.
The DC current of 10^-3 gives the output of 10V.
This plot may tell that the saturation starts even at the 1/10 of the full DC range.
The plot doesn't have many points below 0.1mA.
Consult with my plots for the similar measurements.
The measured points are logarithmically spaced. Use the same technique.
- It is also very unknown that how the noise level is calculated. No info is supplied in the plot or the elogs.
|
Here I am attaching the plot in loglog scale. I have taken the data-points from no light condition to the maximum light condition, the minimum variation possible in the current supply was 0.01A. The noise was visibly decreasing at higher light level.
For the noise level calculation I took the average of total noise in the range 7-60MHz. For each range the formula used was
noisevalue= sqrt(data(:,2)*100)/sqrt(2)/sqrt(channel BW); -- this conversion is needed since the data was collected in the 2 column format: frequency, spectrum(W). |
7933
|
Wed Jan 23 20:27:05 2013 |
Riju | Update | | Photodiode transimpedance |
Today I have repeated the expt for shot noise intercept current. Koji found that the Spectrum analyzer is going to saturation, so we have used one DC blocker (MCL - 15542 model) in PD signal.
I will analyze the data and report.
Ed by Koji: DC BLOCK is BLK-89-S |
7946
|
Mon Jan 28 17:59:02 2013 |
Riju | Update | | Photodiode transimpedance |
Summary: Measurement and plot of shot-noise-intercept-current for PDA255.
Motivation:It is to measure the shot noise intercept current for PDA255 - the MC transmission RF photodiode to get an idea for the noise current for the detector
Result: The final plot is attached here. The plot suggests that the value of shot-noise-intercept current is 3.06mA
Discussion:
The plot is for the measured data of Noise voltage (V/sqrt(Hz)) vs DCcurrent(A). The fitted plot to this measured data follows the noise equation
Vnoise = gdet* sqrt[ 2e (iDC+idet)] , where gdet= transimpedance of the PD in RF region as described in manual of PDA255 (i.e. 5e3 when it is not in High-impedance region).
On the other hand for DCcurrent calculation we must use the high-impedance value for the transimpedance i.e. 1e4 Ohm. idet is the shot noise intercept current.
For the rough calculation of the noise level we may use the following formulae:
Vnoise = gdet*sqrt[2e (iDC+idet)] = gdet*sqrt(2e in), when in=iDC+idet;
For say, in1=1mA; Vnoise1=gdet*sqrt(2e *in1)
and sqrt(2e *in1)~18pA/sqrt(Hz)
In current case dark noise is ~1.5e-7 V/sqrt(Hz)
Therefore dark current(in2) ~dark noise voltage/RF transimpedance = 30pA/sqrt(Hz)
i.e. sqrt(2e *in2)=30pA/sqrt(Hz)
i.e. sqrt(in2/in1)=30/18
therefore, in2~3mA (since in1=1mA)
For, iDC=0, in=idet.
Therefore the shot-noise-intercept current will be ~3mA
Then Vdc = in2*1e4 = 30V
According to the experiment and also from the PDA255 manual the DC voltage level never goes beyond ~10V. Therefore following the photodiode characteristics(we work in reverse bias) we may infer that it can never become shot noise limited.
Also, from PDA255 manual, at 1650nm the dark noise is 30pW/sqrt(Hz) and the responsivity is 0.9A/W. Therefore the noise current level will be = noise power* responsivity ~27pA/sqrt(Hz). The value matches well with our expectation.
|
7956
|
Tue Jan 29 18:40:20 2013 |
Riju | Update | | Photodiode transimpedance |
Today I have taken data for shot noise intercept current for PDA10CF. I will process the data and report.
Note: GPIB address changed, new command for AG4395A network/spectrum analyzer: ./netgpibdata.py -i 192.168.113.108 -d AG4395A -a 10 -f filename |
7972
|
Thu Jan 31 12:44:42 2013 |
Riju | Update | | Photodiode transimpedance |
Today I collected the data for shot noise intercept current for MC REFL PD. I didn't get many data points at higher DC voltage of the photodiode, cause the incandescent bulbs get burnt at that level; two bulbs I have burnt today. I will process the data and report. |
7976
|
Thu Jan 31 15:34:22 2013 |
Riju | Update | RF System | Photodiode transimpedance |
Quote: |
Quote: |
Today I collected the data for shot noise intercept current for MC REFL PD. I didn't get many data points at higher DC voltage of the photodiode, cause the incandescent bulbs get burnt at that level; two bulbs I have burnt today. I will process the data and report.
|
This work was done in-situ, so no optics on the AS table were moved. The PSL shutter was blocked since the IR beam was not necessary, and would scatter off the bulb Riju put in front of the PD.
|
Thanks Jenne. |
7977
|
Thu Jan 31 15:56:38 2013 |
Riju | Update | | Photodiode transimpedance |
Summary: Measurement and plot of shot-noise-intercept-current for PDA10CF.
Motivation:It is to measure the shot noise intercept current for PDA10CF.
Result: The final plot is attached here. The plot suggests that the value of shot-noise-intercept current is 0.21mA
Discussion:
The plot is for the measured data of Noise voltage (V/sqrt(Hz)) vs DCcurrent(A). The fitted plot to this measured data follows the noise equation
Vnoise = gdet* sqrt[ 2e (iDC+idet)] , where gdet= transimpedance of the PD in RF region as described in manual of PDA255 (i.e. 5e3 when it is not in High-impedance region).
To get an approximate idea of the shot noise intercept current, we may follow the same procedure described in 7946
In the present case dark-noise is 4.3e-08 V/sqrt(Hz)
Therefore dark current(in2) ~dark noise voltage/RF transimpedance = 8.6pA/sqrt(Hz)
Therefore the approximate shot noise intercept current ~ (8.6/18)^2=0.22mA
This value matches well with the fitted data.
From PDA10CF manual, NEP=1.2e-11W/sqrt(Hz) and responsivity~0.9A/W. Therefore the noise current level will be ~10pA.
|
7984
|
Fri Feb 1 14:47:17 2013 |
Riju | Update | | Photodiode transimpedance |
Summary: Measurement and plot of shot-noise-intercept-current for MC REFL PD.
Motivation:It is to measure the shot noise intercept current for MC REFL PD.
Result: The final plot is attached here. The plot suggests that the value of shot-noise-intercept current is 0.041mA
Discussion:
The plot is for the measured data of Noise voltage (V/sqrt(Hz)) vs DCcurrent(A). The fitted plot to this measured data follows the noise equation
Vnoise = gdet* sqrt[ 2e (iDC+idet)] , where gdet= transimpedance of the PD in RF region as described in manual of PDA255 (i.e. 5e3 when it is not in High-impedance region).
To get an approximate idea of the shot noise intercept current, we may follow the same procedure described in 7946
In the present case minimum noise value is 2.03e-08 V/sqrt(Hz)
Therefore dark current(in2) ~dark noise voltage/RF transimpedance = 4.06pA/sqrt(Hz)
Therefore the approximate shot noise intercept current value is (4/18)^2 ~ 0.049mA, which is close to the fitted value.
... hard to believe these numbers. Wrong DC transimpedance? (KA) |
8027
|
Thu Feb 7 19:24:57 2013 |
Riju | Update | | Photodiode transimpedance |
Summary: Measurement and plot of shot-noise-intercept-current for MC REFL PD.
Motivation:It is to measure the shot noise intercept current for MC REFL PD.
Result: The final plot is attached here. The plot suggests that the value of shot-noise-intercept current is 1.9mA
Discussion:
The plot is for the measured data of Noise voltage (V/sqrt(Hz)) vs DCcurrent(A). The fitted plot to this measured data follows the noise equation
Vnoise = gdet* sqrt[ 2e (iDC+idet)] , where gdet= transimpedance of the PD in RF region ~600
To get an approximate idea of the shot noise intercept current, we may follow the same procedure described in 7946
In the present case minimum noise value is 1.46e-08 V/sqrt(Hz)
Therefore dark current(in2) ~dark noise voltage/RF transimpedance ~25pA/sqrt(Hz)
Therefore the approximate shot noise intercept current value is (25/18)^2 ~ 1.92mA, which matches well to the fitted value.
|
8186
|
Wed Feb 27 17:43:54 2013 |
Riju | Update | | Photodiode transimpedance |
Here is the transimpedance for the other PD used for MC REFL |
8188
|
Wed Feb 27 18:17:05 2013 |
Riju | Update | | Photodiode transimpedance |
Quote: |
How much is the exact resonant frequency?
And what's the unit of the plot? The resonant "transimpedance" in the unit of Ohm can not be ~100.
|
The exact resonant frequency is 29.38MHz. I ve uploaded the other plot. It was the output of Vectfit. |
8189
|
Wed Feb 27 18:38:51 2013 |
Riju | Update | | Photodiode transimpedance |
Quote: |
Quote: |
How much is the exact resonant frequency?
And what's the unit of the plot? The resonant "transimpedance" in the unit of Ohm can not be ~100.
|
The exact resonant frequency is 29.38MHz. I ve uploaded the other plot. It was the output of Vectfit.
|
Is the DC transimpedance now 10010 Ohm? I ve used 50 Ohm. Which one is correct? |
8484
|
Wed Apr 24 14:24:40 2013 |
Riju | Update | | PD frequency response |
Here I am attaching the first schematic diagram of the PD frequency response set-up, I will keep updating it with relevant informations with the progress of the work.
Description: Our objective is to set-up one simultaneous transfer-function measurement system for all the RF-PDs present in 40m lab. A diode laser will be used to illuminate the PDs. The diode laser output will be divided by 1x16 fiber splitter and will be sent to all the PDs through single-mode fiber. The transfer function of the PDs will be measured using network analyzer(Agilent 4395A). The output of the PDs will be fed to network analyzer via one RF-switch. The diode laser will be controlled by the controller ILX LDC 3744C. The scanning frequency signal will be fed to this controller from network analyzer through its external modulation port. The output of the controller will be splitted into two parts: one will go to laser diode and the other will be used as reference signal for network analyzer.
|
8488
|
Thu Apr 25 00:59:37 2013 |
Riju | Update | RF System | PD frequency response |
Quote: |
I think you have the splitter that splits the RF signal from the network analyzer in the wrong place.
Usually you split the signal immediately after the RF Out, so that half of the signal goes to the A-input of the Analyzer, and the other half goes to your controller (here, the laser diode controller). Then you would take the output of your controller and go straight to the actual laser diode, with no splitting in this path.
|
Here our device under test is the photodiode. So for the reference I wanted to retain the response of the laser diode controller. Otherwise I have to consider the transfer function of that LDC too. I may check both the options at the time of experiment.
Thanks |
8492
|
Thu Apr 25 17:56:28 2013 |
Riju | Configuration | | PD frequency response |
[Eric, Riju]
Today we have routed the fibers from 1x16 fiber splitter to POX table for POX11 PD and POP55 PD. Also we labeled the fibers on AP table, they have been fixed on the table. The photo of the table after work is attached here. We will do it for POX table tomorrow. |
8497
|
Fri Apr 26 17:08:42 2013 |
Riju | Configuration | | PD frequency response |
Quote: |
No.... what I told was to put the roll next to the splitter, not on the table.
The table area is more precious than the rack space.
Koji> The slack of the fibers should be nicely rolled and put together at the splitter side.
|
Ok, will do it on the coming week. |
8506
|
Mon Apr 29 17:26:22 2013 |
Riju | Configuration | RF System | PD frequency response |
Today I have rerouted the fibers on AP table to remove the fiber rolls out of the AP table. I removed the fibers one by one from both ends - from the 1x16 splitter and from the AP table - keeping the fiber roll intact, and then connected it in reverse way, i.e. the fiber end which was on AP table now is connected to the splitter (since length of the outside the roll is shorter that side) and the fiber end connected to splitter is now rerouted on AP table.
We need to keep the fibers in such a fashion so that no sharp bending occurs anywhere, and also it does not get strained due to its weight, particularly near the 1x16 splitter. Jenne suggested to use a plastic box over the splitter rack to keep the fiber rolls for time-being. We discussed a lot how this can be done nicely; in future we may use array of hooks, Koji suggested to use cable hangers and to tie the rolls using more than one hanging point, Jenne suggested to use the bottom shelf of the rack or to use one plastic box with holes. We tried to make holes on the plastic box using drill, but it developed crack on the box. So ultimately I used the opened box only and put it over the rack.
The corresponding photographs are attached herewith.
Tomorrow we will reroute the fibers for POX table. |
8512
|
Tue Apr 30 19:39:14 2013 |
Riju | Configuration | RF System | PD frequency response |
Today I have rerouted the fibers on POX table. The aim was to lay it overhead through the plastic pipe. A pipe ~50ft (~15.5m) long was taken for this purpose. I disconnected the two 25m long fibers for POP55 and POX11 PD (those had been already routed) from both of their ends - i.e. from the POX table and also from 1x16 splitter. Jenne and Koji suggested that we may have another two PDs ( POP22 and POP110) on POX table in future. So we used another 25m long fiber for these two (POP22/POP110). We could not use two fibers for these two since we have only four 25m long fibers and one of them we need for POY11 PD on POY table. Jenne and me put the three fibers inside the pipe using a copper tube. The tube then was put on the overhead rack, Manasa helped me to do it. The fiber ends were finally laid on the POX table at one end and connected to the 1x16 splitter at the other end.
The corresponding photos are attached herewith. |
8520
|
Wed May 1 17:36:26 2013 |
Riju | Configuration | RF System | PD frequency response |
Today I routed fiber from 1x16 splitter to POY table. Manasa helped me doing that. The fiber(25m) was laid on overhead rack through plastic pipe of length ~76ft. We put the fiber inside the pipe using one copper tube, and then tied the plastic pipe on the overhead rack. Finally one end of the fiber was laid on POY table and the other end was connected to the 1x16 splitter. The photographs corresponding are attached. There is no picture of splitter end, cause it was dark that time. |
8573
|
Tue May 14 19:52:58 2013 |
Riju | Configuration | RF System | PD frequency response |
[Eric, Riju, Annalisa]
Today we have cleared up the fiber spool near AP table. We have put the 1x16 fiber splitter and a box (we made two openings on it) for fiber spool on a different part of the rack. Also put a plastic tubing or the fibers coming out of AP table. Now the fibers coming out from AP table and also from POX table first enter the box through one opening and the end of the fibers come out of the other opening to get connected to to splitter. Photographs of the work are attached. I don't think enough fiber is there to make a similar loop for fiber coming from POY table.
|
7486
|
Thu Oct 4 23:01:49 2012 |
Rijuparna | Configuration | | cavitymode scan |
Here I am attaching the schematic diagram of the experimental set-up for IMC cavitymode scanning. A 30- 45MHz scanning signal generated by Agilent 4395A network analyzer enters EOM, which in turn modulates the laser beam entering IMC. The cavity response can be verified from reflected/transmitted beam.
I worked with the reflected beam last days. But I got no clue about the percentage of reflected light reaching the photodiode and also the photodiode response. I would like to measure the power reaching photodiode and also would like to perform the test with transmitted beam - on wednesday if possible.
|
7519
|
Wed Oct 10 15:31:59 2012 |
Rijuparna | Update | | cavitymode scan |
Rijuparna, Jenne
Today I checked the optical lay-out in MC REFL board of the MC REFL path on the AS table (I will put the updated diagram in a few hours), and took a record of the reflected power of unlocked MC and power entering MC REFL PD. The power coming out of MC cavity when unlocked is 1.25W and power entering REFL PD 112mW (Jenne measured these powers for me).
I also got a description of the MC demodulation board from Jenne.
(Edits by Jenne) |
7537
|
Fri Oct 12 15:31:03 2012 |
Rijuparna | Configuration | | cavitymode scan |
Rijuparna, Manasa
Today I have checked the optical layout of the MC transmission RFPD table and measured the laser powers at different points. Manasa helped me for that. I found the power entering the RF photodiode is 0.394mW while the transmitted power of the cavity is 2.46mW. (I will give the diagram later). |
7351
|
Thu Sep 6 17:06:25 2012 |
Rijuparna Chakraborty | Configuration | elog | Cavitymode scan |
Aim: to scan the cavitymodes of IMC
The circuit used:
Attachment4
Results obtained:
Attachment 1,2,3
|
7363
|
Fri Sep 7 15:58:29 2012 |
Rijuparna Chakraborty | Update | | cavitymode scan |
IMC transmission photodiode has been aligned. |
7368
|
Sat Sep 8 00:15:57 2012 |
Rijuparna Chakraborty | Update | | cavitymode scan |
Quote: |
Quote: |
IMC transmission photodiode has been aligned.
|
Which PD? The 'regular' DC one, or the newer one? Why did it need realigning? What mirrors did you touch to do the alignment?
Did you do anything else in the last 3 days? I want to see ALL the gory details, because it can help people doing future measurements, or help us debug if something is wrong with the interferometer later.
MORE WORDS! Thanks.
|
No, not the "regular DC one", the "newer one" along with the controls of the corresponding mirror only i touched.
It needed to be realigned cause last week when we fitted a longer cable there, which may reach the network analyzer, it got misaligned since it got touched.
No other component in that box except that PD and the corresponding mirror controls I touched.
For my last 2 days work, I feel my last elog is reliable.
Today other than doing this, I checked for the higher order modes of the cavity, misaligning one of the MC mirror though the software only. I didn't mention it in my elog cause although I saw the presence of the higher order modes I didn't record it, so I can not upload any picture in support of such a statement.
Thanks |
7376
|
Wed Sep 12 19:26:08 2012 |
Rijuparna Chakraborty | Update | | cavitymode scan |
Summary: Recorded the presence of higher order modes in IMC
What I did: Misaligned the flat mirror MC1 by small amount in both pitch and yaw (it was needed to be done cause at the beginning of the experiment no higher order modes were present) and scanned the cavity for frequency-range 32MHz to 45MHz.
I found the presence of higher order modes around 36.7MHz (1st order) and 40.6MHz (2nd order) along with two other strong modes near 35MHz and 42.5MHz.
|
603
|
Mon Jun 30 14:07:26 2008 |
Rob | Configuration | PSL | Don't put the bin in front of the air conditioning unit |
Quote: | We spotted that the laser power was dropping.
|
the offending configuration: |
1306
|
Sun Feb 15 15:53:21 2009 |
Rob | Update | LSC | Locking status |
Quote: |
I didn't get a chance to do much testing since the sus controller (susvme1) went nuts. In retrospect, this could be due to something in the script, so maybe we should try a burt restore to Friday afternoon next time someone wants to look at it. |
I tried the burt restore today, it didn't work. Also tried some switching of timing cables, and multiple reboots, to no avail. This will require some more debugging. We might try diagnosing the clock driver and fanout modules, the penteks, and we can also try rebooting the whole FE system. |
623
|
Wed Jul 2 13:56:10 2008 |
Rob, Yoichi, John | Update | Locking | 24.5 Hz resonance |
Work continues on trying to reduce the CARM offset using dc signals from PO_DC. Got up to arm powers of
~35 last night.
We found that progress was stymied by an oscillation around 24 Hz. This oscillation was clearly visible
in the intensity of the light at REFL, PO and TrX.
Initially we suspected that this oscillation was due to an instability in the CARM loop. We attempted to
solve the problem by tuning the crossover frequncy of the AO and MC_L paths and shaping the MC_L loop to
reduce the impact of the 24 Hz noise.
After some quick tests we found that the 24 Hz signal was present even when dc CARM was used. It appears
that the peak is in fact due to a SOS mechanical resonance. We currently suspect a roll mode.
We're going to check that PRC, MICH and DARM have filters to attenuate the 24 Hz line. We'll also look at the
SUS_POS bandstop filters to see where they are centred.
The ISS was behaving strangely again. Constantly saturated at 5dB of gain. Someone needs to look a this. |
630
|
Thu Jul 3 13:12:32 2008 |
Rob, Yoichi, John | Update | Locking | More oscillations |
Bounce/ roll filters were added to the short degrees of freedom to reduce the effect of the 24Hz line seen on Tuesday night.
However last night saw the arrival of a new oscillation at ~34Hz. This may be the second harmonic of the MOS roll mode. Reducing the arm offset would cause this oscillation to ring up and break the lock (first plot). This effect was repeatable.
No signal was seen in the oplevs or osems which leads us to rule out alignment problems, at least for now.
Although one can clearly see DARM_ERR increasing as arm power increases adding a resonant gain in the DARM loop had no effect.
We also noticed that x arm transmission was significantly more noisy than the Y (second plot). And showed greater coherence with the increase in DARM noise. Investigations showed that the PD was not the source of the difference.
Turning up the MC gain seems to help a little.
We're now looking at POX as a candidate for RF_CARM (third plot). |
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Mon May 7 20:01:14 2018 |
Rorpheus | Update | General | Use anti-dewhitening + show CARMA/DARMA |

example of plots illustrating DAC range / saturation |
6422
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Thu Mar 15 08:48:40 2012 |
Ryan | Summary | CDS | Summary of Syracuse Visit to 40m Mar 5-9 2012 |
JIMS Channels in PEM Model
The PEM model has been modified now to include the JIMS(Joint Information Management System) channel processing. Additionally Jim added test points at the outputs of the BLRMS.
For each seismometer channel, five bands are compared to threshold values to produce boolean results. Bands with RMS below threshold produce bits with value 1, above threshold results in 0. These bits are combined to produce one output channel that contains all of the results.
A persistent version of the channel is generated by a new library block that called persist which holds the value at 0 for a number of time steps equal to an EPICS variable setting from the time the boolean first drops to zero. The persist allows excursions shorter than the timestep of a downsampled timeseries to be seen reliably.
The EPICS variables for the thresholds are of the form (in order of increasing frequency):
C1:PEM-JIMS_GUR1X_THRES1
C1:PEM-JIMS_GUR1X_THRES2
etc.
The EPICS variables for the persist step size are of the form:
C1:PEM-JIMS_GUR1X_PERSIST
C1:PEM-JIMS_GUR1Y_PERSIST
etc.
The JIMS Channels are being recorded and written to frames:
The two JIMS channels at 2048:
[C1:PEM-JIMS_CH1_DQ] Persistent version of JIMS channel. When bit drops to zero indicating something bad (BLRMS threshold exceeded) happens the bit stays at zero for >= the value of the persist EPICS variable.
[C1:PEM-JIMS_CH2_DQ] Non-persistent version of JIMS channel.
And all of the BLRMS channels at 256:
Names are of the form:
[C1:PEM-RMS_ACC1_F0p1_0p3_DQ]
[C1:PEM-RMS_ACC1_F0p3_1_DQ]
For additional details about the JIMS Channels and the implementation, please see the previous elog entries by Jim.
Conlog
I have a working aLIGO Conlog/EPICS Log installed and running on megatron.
Please see this wiki page for the details of use:
https://wiki-40m.ligo.caltech.edu/aLIGO%20EPICs%20log%20%28conlog%29
I also edited this page with restart instructions for megatron:
https://wiki-40m.ligo.caltech.edu/Computer_Restart_Procedures#megatron
Please see Ryan's previous elog entries for installation details.
Future Work
- Determine useful thresholds for each band
- Generate MEDM Screens for JIMS Channels
- Add a decimation option to channels
- Add EPICS Strings in PEM model to describe bits in JIMS Channels
- Add additional JIMS Channels: Testing additional characterization methods
- Implement a State Log on Megatron: Will Provide a 1Hz index into JIMS Channels
- Generate a single web page that allows access to aLIGO Conlog/EPICS Log and State Log
|
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Wed Apr 11 12:25:11 2012 |
Ryan | Update | Computers | Updating aLIGO Conlog |
Over the next few days, I will be working on upgrading the aLIGO Conlog install to include new bugfixes distributed by Patrick T. The currently running conlog *should* not be affected, but please let me know if it is (ryan.fisher@ligo.org). |
6539
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Tue Apr 17 10:55:50 2012 |
Ryan | Update | Computers | Updating aLIGO Conlog |
Quote: |
Over the next few days, I will be working on upgrading the aLIGO Conlog install to include new bugfixes distributed by Patrick T. The currently running conlog *should* not be affected, but please let me know if it is (ryan.fisher@ligo.org).
|
The upgrade to the aLIGO Conlog is completed. The conlog is once again running on megatron in a screen session. (see http://nodus.ligo.caltech.edu:8080/40m/6396) |
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Wed Mar 7 13:59:07 2012 |
Ryan Fisher | Summary | Computer Scripts / Programs | Alterations to base epics install for installing aLIGO conlog: |
In order to install the necessary extensions to epics to make the aLIGO conlog work, I have edited one file in the base epics install that affects makefiles:
/cvs/cds/caltech/apps/linux64/epics/base/configure/CONFIG_COMMON
Jamie said he prefers diffs, so I regenerated the original file and did a diff against the current file:
megatron:configure>diff CONFIG_COMMON.orig.reconstructedMar72012 CONFIG_COMMON.bck.Mar72012
206,207c206,210
< USR_CPPFLAGS =
< USR_DBDFLAGS =
---
> USR_CPPFLAGS = -I $(EPICS_BASE)/include
> USR_CPPFLAGS += -I $(EPICS_BASE)/include/os/Linux/
> USR_CPPFLAGS += -I $(EPICS_BASE)/../modules/archive/lib/linux-x86_64/
> USR_DBDFLAGS = -I $(EPICS_BASE)/dbd
> USR_DBDFLAGS += -I $(EPICS_BASE)/../modules/archive/dbd
This is saved in CONFIG_COMMON.diff.Mar72012_1 |
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Wed Mar 7 18:00:39 2012 |
Ryan Fisher | Summary | Computer Scripts / Programs | Alterations to base epics install for installing aLIGO conlog: |
Quote: |
In order to install the necessary extensions to epics to make the aLIGO conlog work, I have edited one file in the base epics install that affects makefiles:
/cvs/cds/caltech/apps/linux64/epics/base/configure/CONFIG_COMMON
Jamie said he prefers diffs, so I regenerated the original file and did a diff against the current file:
megatron:configure>diff CONFIG_COMMON.orig.reconstructedMar72012 CONFIG_COMMON.bck.Mar72012
206,207c206,210
< USR_CPPFLAGS =
< USR_DBDFLAGS =
---
> USR_CPPFLAGS = -I $(EPICS_BASE)/include
> USR_CPPFLAGS += -I $(EPICS_BASE)/include/os/Linux/
> USR_CPPFLAGS += -I $(EPICS_BASE)/../modules/archive/lib/linux-x86_64/
> USR_DBDFLAGS = -I $(EPICS_BASE)/dbd
> USR_DBDFLAGS += -I $(EPICS_BASE)/../modules/archive/dbd
This is saved in CONFIG_COMMON.diff.Mar72012_1
|
After following up with Patrick Thomas for a while trying to make the extensions to epics work within the currently installed epics, he decided that we should just start over with a fresh install of epics 3.14.10.
I am installing this in /ligo/apps/linux-x86_64/epics/base-3.14.10/
Prior to all of this, I had done a lot of installation and configuration of the packages needed to make LAMP work:
sudo apt-get install lamp-server^
sudo apt-get install phpmyadmin
I then continued to follow the instructions on Patrick's wiki:
https://awiki.ligo-wa.caltech.edu/aLIGO/Conlog#EDCU_library
I installed the c_string library into /ligo/apps/linux-x86_64/ according to his instructions. (prior to my installs, there was no /ligo/ on this machine at all, so I made the needed parent directories with the correct permissions).
That should be everything up to installing epics (working on that now). |
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Thu Mar 8 17:18:19 2012 |
Ryan Fisher | Summary | Computer Scripts / Programs | Alterations to base epics install for installing aLIGO conlog: |
I have the aLIGO Conlog 'working' at http://192.168.113.209/conlog/conlog.php
The process is running inside a screen on megatron.
To start it running, you need to set your environment, and then run the startup.c1conlog script :
cd /cvs/cds/rtcds/caltech/c1/target/conlog/conlogepics
source conlog_environment.txt
./startup.c1conlog
This will leave you at an epics prompt, which means the code is running. (that's why I left it running in a screen for now).
To change the list of channels when the conlog is running, you need to edit the file (s):
/ligo/caltech/data/conlog/c1/add_channel_names
/ligo/caltech/data/conlog/c1/remove_channel_names
Then start up medm as follows:
cd ~/ryan/
medm -x -macro "IFO=C1" medm/CONLOG.adl
Then click the Add channel list button or Remove channel list button.
To change the channels before running the conlog from a blank database, you would edit:
/ligo/caltech/data/conlog/c1/use_channel_names (I believe this should be read whenever the conlog is restarted, but I'm only sure it does the first time you start conlog).
Documenting the rest of the installation:
Successful? Installation of Fresh EPICS and Extensions
Fresh Copy of EPICS 3.14.10
* We restarted (on Patrick's suggestion) with a fresh copy of EPICS 3.14.10 in:
/ligo/apps/linux-x86_64/epics
* I had to set a clean environment:
* Then I downloaded the tarball, unpacked it, and simply ran make within it, and it worked!
* Next, I followed Patrick's wiki instructions with only modifications to the configure/RELEASE files for the archive and ioc/conlog extensions.
* Then I realized that I had to rebuild conlog ioc after adding a directory:
/ligo/apps/linux-x86_64/epics/iocs/conlog/iocBoot/iocc1_conlog
* I had to copy the files from the h1 directory and modify them so that all reference to h1 now point to c1 in the new directory
* I then rebuilt the conlog ioc (I had to make sure setenv SCRIPTS was run again because I had logged out and back in, and I reset the whole environment properly again)
Rest of Install
* I was able to fairly trivially follow through the rest of the installation steps on Patrick's wiki, up to the "Design" section.
* Now, there is no obvious way to move forward (nothing is actually running I believe).
New Install Instructions:
"
You want to create the EPICS IOC boot directory by doing the following:
In the top level of the IOC (.../epics/iocs/conlog) with the appropriate
paths:
/epics/base/bin/linux-x86_64/makeBaseApp.pl -i -t ioc c1_conlog
What application should the IOC(s) boot?
The default uses the IOC's name, even if not listed above.
Application name? conlog
Then you will have to update the st.cmd it creates. You can compare the
st.cmd and st.cmd.backup files in the other directories to see what needs
to be changed.
I don't know if just copying the directory will work, it might.
You will also probably want to change the following line in
/epics/modules/archive/archiveApp/src/drvArchive.c:
queue = epicsMessageQueueCreate(100000000, sizeof(struct message_type));
and reduce 100000000 to something smaller depending on the amount of ram
available to the computer. I think sizeof(struct message_type) is
something like 112 bytes. Then recompile.
You basically put a file with the list of channels to use in the directory
path for "use channel list filepath" in the following command in st.cmd:
drvArchive_read_channel_list_filepaths <add channel list filepath>,<remove
channel list filepath>,<use channel list filepath>
I can send you the script that I currently use to generate that channel
list if you want, but it may need to be changed for your setup.
Once you start the ioc, open the medm which can be checked out from
subversion here: cds_user_apps/trunk/cds/common/medm/CONLOG.adl
with macro substitution for IFO: medm -x -macro "IFO=C1"
and click on the button for "Use channel list".
The number of monitored channels should increase to the number of channels
in the file.
-Patrick
...
The perl script and example file are attached, just redirect the output of
the perl script to a file. It scans autoBurt.req files in a particular
directory and its subdirectories for channel names that meet certain
criteria. All the file contains is a list of channel names, one on each
line. To start the IOC, go to the target directory and run
./startup.c1conlog.
"
{{rpfisher:scan_autoburt.pl.txt|scan_autoburt.pl.txt}}
{{rpfisher:use_channel_names.txt|use_channel_names.txt}}
My Notes Regarding These Instructions:
* Throughout the installation instructions, it probably should have been made clear that the ifo is lowercase: eg c1 (but in the end the installation mixed C1 and c1 in different places)
* Also throughout, one should be careful to replace lho with your site (eg caltech) wherever it appears
* After running the first perl script to generate the iocBoot/iocc1_conlog directory, the goal is to rebuild the whole conlog ioc by running make from epics/iocs/conlog, but before doing that:
* I needed to change the suggested line in the archive module to match the correct RAM size of the machine I am installing on (I actually gave it just less than half the free RAM), then:
* Remake the archive module
* Change into the ioc/conlog directory, remove the iocBoot I had made before for c1, rerun the perl script above, then run make from the ioc/conlog directory.
* Once that is done, you need to edit the file st.cmd to add lines for the reading and writing of channels, such as:
dbLoadRecords("db/conlog.db","IFO=C1")
drvArchive_mysql "C1_conlog","/data/mysql/C1_conlog_epics_user"
drvArchive_read_channel_list_filepaths "/ligo/caltech/data/conlog/c1/add_channel_names","/ligo/caltech/data/conlog/c1/remove_channel_names","/ligo/caltech/data/conlog/c1/use_channel_names"
drvArchive_write_channel_list_filepaths "/ligo/caltech/data/conlog/c1/channel_names","/ligo/caltech/data/conlog/c1/monitored_channel_names","/ligo/caltech/data/conlog/c1/unmonitored_channel_names"
* I also had to rerun this set of commands once that was all done:
controls: cd /opt/rtcds/<site>/<ifo>/target/conlog/conlogepics
controls: cp -r /ligo/apps/linux-x86_64/epics/iocs/conlog/db ./
controls: cp -r /ligo/apps/linux-x86_64/epics/iocs/conlog/dbd ./
controls: cp /ligo/apps/linux-x86_64/epics/iocs/conlog/iocBoot/ioc<ifo>_conlog/envPaths ./
controls: cp /ligo/apps/linux-x86_64/epics/iocs/conlog/iocBoot/ioc<ifo>_conlog/st.cmd ./
controls: echo ./bin/linux-x86_64/conlog st.cmd > startup.<ifo>conlog
controls: chmod a+x startup.<ifo>conlog
* This set of instructions seemed to be lacking, so I added this:
cp -r /ligo/apps/linux-x86_64/epics/iocs/conlog/bin/ ./
* Now the executable runs but doesn't work:
* Fixes needed:
* Need to use root permissions and make sure the files in /data/mysql have the right names for the users the code expects and also have the right passwords. (have to match capitalization appropriately for the <ifo> tag everywhere
* Might need to go into mysql and add a new user with the proper capitalization also
* Need to edit the ld_library_path to point to the new epics libraries (see the suggested environment below)
* Now, the code seems to work, but dumps me at an "epics> " prompt, I'm asking Patrick what to do next.
* I was impatient and loaded up the medm screen, and found out that the one channel I had picked was not readable (unmonitored)
* I ran a modified version of Patrick's perl script to search autoBert files for channels, and replaced my use_channel_names file with the output of the script
* Now, the medm screen shows lots of monitored channels, and the conlog is filling up! (can see it from phpmyadmin)
* Next step: I wanted to get the php pages working, so I edited the files inside /var/www/conlog:
megatron:~/ryan>diff -u /var/www/conlog/conlog.php /var/www/conlog/conlog.php.bck.Mar82012_1
--- /var/www/conlog/conlog.php 2012-03-08 15:31:53.152547771 -0800
+++ /var/www/conlog/conlog.php.bck.Mar82012_1 2012-03-08 15:28:23.062704171 -0800
@@ -19,7 +19,7 @@
<form action="query.php" method="post">
<h3><label for="database">Database:</label></h3>
<select id="database" name="database">
- <option value="C1_conlog">C1</option>
+ <option value="h2_conlog">h2</option>
</select>
<h3><label for="included_channels">Included channels:</label></h3>
megatron:~/ryan>diff -u /var/www/conlog/query.php /var/www/conlog/query.php.bck.Mar82012_1
--- /var/www/conlog/query.php 2012-03-08 15:33:45.122550303 -0800
+++ /var/www/conlog/query.php.bck.Mar82012_1 2012-03-08 15:32:31.772554679 -0800
@@ -168,8 +168,8 @@
}
$database_name = $_POST["database"];
- if ($database_name == 'C1_conlog') {
- $server = '192.168.113.209';
+ if ($database_name == 'h2_conlog') {
+ $server = 'cdsconlog';
}
else {
die('Unknown database.');
* Finally, the mysql server was denying access from outside queries, so I fixed that:
megatron:~/ryan>diff -u /etc/mysql/my.cnf /etc/mysql/my.cnf.bck.Mar82012_1
--- /etc/mysql/my.cnf 2012-03-08 15:35:57.122548370 -0800
+++ /etc/mysql/my.cnf.bck.Mar82012_1 2012-03-08 15:35:10.652559315 -0800
@@ -49,7 +49,7 @@
#
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
-#bind-address = 127.0.0.1
+bind-address = 127.0.0.1
#
# * Fine Tuning
#
megatron:~/ryan>
* Now, I think everything is working * almost:
* It seems that when you first start the conlog up, it finds all the variables and inserts values of "Null" for everything, but after that it detects changes properly!
Conlog Environment
Need to source this to use the new environment:
megatron:~>cat ~/ryan/conlog_enviroment.txt |
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Fri Mar 9 11:02:56 2012 |
Ryan Fisher | Summary | Computer Scripts / Programs | Alterations to base epics install for installing aLIGO conlog: |
Too Many Fast Changing EPICS in New Conlog
I have been monitoring the new conlog, and it already has far too many rows.
I'm going through the list of channels to exclude in the update_channels script for the conlog that is currently running and removing them from
the monitored channels in the new conlog using the remove_channel_names file and the medm screen (we may want to just wipe out the tables
and start over after this is set properly, but for now I'm keeping them):
#-- Exclude a few uninteresting or obsolete categories
if ( $chan =~ m/^[BIJ]$/ ||
$chan =~ m/IOO-MC_PWR_IN/ ||
$chan eq "C1:PSL-FSS_SLOWDC" ||
$chan =~ m/PSL-STAT_.*_BITS/ ||
$chan =~ m/:IOO-PZTM[12]_(PIT|YAW)_BIAS$/ ||
$chan =~ m/DAQ.*_cycle/ ||
$chan =~ m/DAQ.*rtSeconds/ ||
$chan =~ m/C1:-.*/ ||
$chan =~ m/C1:SUP/ ||
$chan =~ m/C1:SP/ ||
$chan =~ m/C1:X/ ||
$chan =~ m/C1:TST/ ||
$chan =~ m/C1:RF/ ||
$chan =~ m/C1:UCT/ ||
$chan =~ m/C1:DU/ ||
$chan =~ m/C1:MCP/ ||
$chan =~ m/C1:MCS/ ||
$chan =~ m/C1:FEC/ ||
$chan =~ m/C1:PEM/ ||
$chan =~ m/C1:LSP/ ||
$chan =~ m/C1:NIO/ ||
$chan =~ m/C1:WFS/ ||
$chan =~ m/C1:ASC-WFS/ ||
$chan =~ m/C1:ASC-SP/ ||
$chan =~ m/C1:VG/ ||
$chan =~ m/C1:IOO-DOF/ ||
$chan =~ m/C1:IOO-EO/ ||
$chan =~ m/Name/ ||
$chan =~ m/DEFAULTNAME/ ||
$chan =~ m/:IOO-PZT.*OFFSET/ ||
$chan =~ m/PD_VAR$/ ||
$chan =~ m/_INMON$/ ||
$chan =~ m/_EXCMON$/ ||
$chan =~ m/_OUT16$/ ||
$chan =~ m/_OUTMON$/ ||
$chan =~ m/_OUTPUT$/ ||
$chan =~ m/_RSET$/ ||
$chan =~ m/_ALIVE$/ ||
$chan =~ m/VMon$/ ||
$chan =~ m/PDMon$/ ||
$chan =~ m/(BiasVMon|FE_PPOLL|MASTER_OVERFLOW|FSS_TIDALSET|CPU_LOAD|CDM
_STAT|State_Bits|INDCOFFSET)/ )
With these removals, only 15493 channels are being monitored now. |
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Fri Mar 9 15:48:56 2012 |
Ryan Fisher | Summary | Computer Scripts / Programs | Alterations to base epics install for installing aLIGO conlog: |
I decided to make a backup of the database and then delete it and make a new database:
cd ~/ryan/database_dumpMar92012
mysqldump -u root -p C1_conlog > C1_conlog.dump.Mar92012 Note: it appears this failed the first time, thankfully this wasn't a production service yet... In the future, do not trust this backup method for important data!
Next, log into mysql as root, dump the database, remake it and grant privileges again.:
(This is saved in megatron:~/ryan/restore_database.txt
megatron:~/ryan>mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 174
Server version: 5.1.41-3ubuntu12.10 (Ubuntu)
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> list databases;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'list databases' at line 1
mysql> list users; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'list users' at line 1
mysql> use C1_conlog
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> list users;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'list users' at line 1
mysql> select User from mysql.user; +------------------+
| User |
+------------------+
| php |
| C1_conlog_epics |
| c1_conlog_epics |
| root |
| C1_conlog_epics |
| c1_conlog_epics |
| debian-sys-maint |
| root |
| root |
+------------------+
9 rows in set (0.00 sec)
mysql> show databases; +--------------------+
| Database |
+--------------------+
| information_schema |
| C1_conlog |
| mysql |
+--------------------+
3 rows in set (0.00 sec)
mysql> drop database C1_conlog ;
Query OK, 2 rows affected (0.56 sec)
mysql> create database C1_conlog;
Query OK, 1 row affected (0.00 sec)
mysql> use C1_conlog ;
Database changed
mysql> SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO";
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> CREATE TABLE `channels` (
-> `channel_id` mediumint(8) unsigned NOT NULL AUTO_INCREMENT,
-> `channel_name` varchar(60) NOT NULL,
-> PRIMARY KEY (`channel_id`),
-> UNIQUE KEY `channel_name` (`channel_name`)
-> ) ENGINE=MyISAM DEFAULT CHARSET=latin1;
Query OK, 0 rows affected (0.04 sec)
mysql>
mysql> CREATE TABLE `data` (
-> `acquire_time` decimal(26,6) NOT NULL,
-> `channel_id` mediumint(8) unsigned NOT NULL,
-> `value` varchar(40) DEFAULT NULL,
-> `status` tinyint(3) unsigned DEFAULT NULL,
-> `connected` tinyint(1) unsigned NOT NULL,
-> PRIMARY KEY (`channel_id`,`acquire_time`)
-> ) ENGINE=MyISAM DEFAULT CHARSET=latin1;
Query OK, 0 rows affected (0.03 sec)
mysql> grant select, insert, update, execute on * to 'c1_conlog_epics'@'127.0.0.1'; Query OK, 0 rows affected (0.00 sec)
mysql> grant select, insert, update, execute on * to 'C1_conlog_epics'@'127.0.0.1'; Query OK, 0 rows affected (0.00 sec)
mysql> grant select, insert, update, execute on * to 'c1_conlog_epics'@'localhost'; Query OK, 0 rows affected (0.00 sec)
mysql> grant select, insert, update, execute on * to 'C1_conlog_epics'@'localhost';
Query OK, 0 rows affected (0.00 sec)
mysql> grant select on C1_conlog to 'php'@'%';
ERROR 1146 (42S02): Table 'C1_conlog.C1_conlog' doesn't exist
mysql> grant select on * to 'php'@'%';
Query OK, 0 rows affected (0.00 sec)
mysql> select * from mysql.users
-> ;
ERROR 1146 (42S02): Table 'mysql.users' doesn't exist
mysql> select User from mysql.user;
| C1_conlog_epics |
| c1_conlog_epics |
| root |
| C1_conlog_epics |
| c1_conlog_epics |
| debian-sys-maint |
| root |
| root |
+------------------+
9 rows in set (0.00 sec)
mysql> Bye
Next, I decided that I want to index on the acquire_time instead of the combination of channel_id and acquire_time (I think it makes a lot of sense for several query types, and especially debugging the conlog!):
mysql> create index acquire_time_index on data(acquire_time);
Query OK, 0 rows affected (0.04 sec)
Records: 0 Duplicates: 0 Warnings: 0
Next Fix:
The above worked well, but when I restarted the conlog, I had to re-execute the "remove_channels" from the medm, because initially all channels were being loaded (use_channel_names had all the channels still).
Additionally, there were a lot of channels with "*RMS*" in the name that were being recorded, and were changing relatively quickly, so I have added those to the remove_channel_names file.
I am going to: Backup the files in /ligo/caltech/data/conlog/c1
Edit use_channel_names to only have the good channels.
Dump the database again
Stop conlog.
Wipe the database again.
Remake the database again (with permissions and the new index).
Restart the conlog and hope!
The fix above seems to be in place and working. The database has the initial entries for the channels it monitors and is not growing without operators changing EPICs values. |