 Wed May 13 15:13:11 2020, Yehonathan, Update, Loss Measurement, 40m Phase maps loss estimation 
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Koji pointed out during the group meeting that I should compensate for local tilt when I move the beam around the mirror for calculating the loss map.
So I did.
Also, I made a mistake earlier by calculating the loss map for a much bigger (X7) area than what I thought. |
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Thu May 14 12:21:56 2020, Yehonathan, Update, Loss Measurement, 40m Phase maps loss estimation
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I finished calculating the X Arm loss using first-order perturbation theory. I will post the details of the calculation later.
I calculated loss maps of ITM and ETM (attachments 1,2 respectively). It's a little different than previous calculation because now both
mirrors are considered and total cavity loss is calculated. The map is calculated by fixing one mirror and shifting the other one around. |
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Thu May 14 19:00:43 2020, Yehonathan, Update, Loss Measurement, 40m Phase maps loss estimation
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Perturbation theory:
The cavity modes , where q is
the complex beam parameter and m,n is the mode index, are the eigenmodes of the cavity propagator. That is: |
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Tue May 19 15:39:04 2020, Yehonathan, Update, Loss Measurement, 40m Phase maps loss estimation
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I have a serious concern about this low angle scattering analysis:
Phase maps perturb the spatial mode of the steady-state of the cavity, but how is this different than mode-mismatch?
The loss that I calculated is an overall loss, not roundtrip loss. |
 Wed Jun 24 22:47:21 2020, Yehonathan, Update, Wiki, Updated phase maps webpage
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I uploaded the new phase maps measurements made by GariLynn to nodus and updated the optics phase maps page.
I
also added MetroPro and Matlab analysis for these phase maps. |
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Thu Aug 6 00:34:38 2020, Yehonathan, Update, BHD, Monte Carlo Simulations 8x
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I've pushed an MCMC simulation to the A+ BHD repo (filename MCMC_TFs.ipynb). The idea is to show how random offsets around ideal IFO change the noise
couplings of different DOFs to readout.
At each step of the simulation: |
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Mon Aug 10 07:13:00 2020, Yehonathan, Update, BHD, Monte Carlo Simulations 8x
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I fixed some stuff in the MCMC simulation:
1. Results are now plotted as shades from minimum to maximum. I tried making the shade the STD around a mean but it doesn't look good on
a log scale when the STD is bigger than the mean. |
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Tue Aug 25 05:51:29 2020, Yehonathan, Update, BHD, Monte Carlo Simulations 8x
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I re-plotted the MCMC results as semi-transparent lines so that probable lines stick out.
This also reveals what is behind the extreme sparsity in the aLIGO simulation results (In the previous post).
There seem to be some bi-stability/phase transition/whatever in the aLIGO simulation. The aLIGO transfer functions are very sensitive to one |
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Mon Sep 14 07:50:01 2020, Yehonathan, Update, BHD, Monte Carlo Simulations 10x
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Turns out what was causing the instability in the aLIGO plots were the lock commands which I forgot to remove before running the simulation.
Removing these also made the simulation much faster.
Other than that I improved other stuff in the simulations: |
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Fri Oct 16 09:16:37 2020, Yehonathan, Update, BHD, Monte Carlo Simulations 8x
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Pushed another update to MCMC simulation. This includes:
Added new imbalances: ITM transmission, ITM & ETM RoCs.
Added new static offsets: DHARD, DSOFT, CHARD, CSOFT. All pitch.
The RMS is calculated from the data Jon fetched with /input_noises/input_noises.ipynb.
SRCL noise ASD and RMS are now taken from data in /input_noises.
RF |
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Thu Oct 22 11:48:08 2020, Yehonathan, Update, BHD, Monte Carlo Simulations 8x
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I found this H1 alog entry by Izumi confirming that the calibrated
channels CAL-CS_* need the same dewhitening filter.
This encouraged me to download the PRCL and MICH data and using Jon's example notebook. I incorporated these noise spectra into the MCMC |
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Thu Dec 10 14:48:00 2020, Yehonathan, Update, BHD, Monte Carlo Simulations
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I have rebuilt the MCMC simulation in an OOP fashion and incorporated Lance/Pytickle functionality into it. The usage of the MCMC now is much less messy,
hopefully.
I made an example that calculates the closed-loop noise-coupling from SRCL sensing and displacement to DARM in A+. I used the control filters |
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Mon Dec 14 11:09:28 2020, Yehonathan, Update, BHD, Monte Carlo loop coupling Simulations
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I spent a few hours monkeying around with the control filters. They are totally made up and also it's my first time trying to design control filters.
The OLTFs of the different length controls are shown in attachment 1.
The open-loop couplings of the DOFS to DARM are shown in attachment 2. |
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Mon Jan 11 16:11:51 2021, Yehonathan, Update, BHD, Monte Carlo loop coupling Simulations
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I dived into the alog to make the OLTFs in the MC_controls example more realistic. I was mainly inspired by these entries:
https://alog.ligo-la.caltech.edu/aLOG/uploads/47116_20190708131007_carmolg_20190702.png
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=18742 |
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Thu Feb 4 15:14:55 2021, Yehonathan, Update, BHD, SOS assembly
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I gathered all the components I could find from the SOS towers and the cleanroom and put it all on the table next to the flow bench (See attachment).
I combed through the cleanroom cabinet for SOS parts but didn't find all the parts listed in the procurement
spreadsheet. I did find some extra items that were not listed. |
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Tue Feb 16 13:13:39 2021, Yehonathan, Update, BHD, SOS assembly
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Gautam pointed out that there are extra Sm-Co magnets stored in the clean optics cabinet.
I took the magnet box out and put it on the rolling table next to south flow bench. The box contains 3 envelopes with magnets.
They are labelled as following: |
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Tue Feb 16 22:59:36 2021, Yehonathan, Update, BHD, SOS assembly
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Done.
Also, the magnets are nickel-plated. I guess that doesn't matter for the baking (Curie temp of 355 °C)?
Quote:
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Fri Feb 19 12:21:04 2021, Yehonathan, Update, BHD, SOS assembly
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A summary of things that need to be fabricated/purchased/done:
Part
What needs to be done
How much more needed
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Mon Feb 22 14:06:49 2021, Yehonathan, Update, SUS, OSEM testing for SOSs
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Continuing with the OSEM testing. I measure the resistance of the wires from the RLC meter to the coil to be ~ 0.9ohm. I will subtract this number from
the subsequent coil resistance measurements.
I took the old MC1 satellite box for powering the PD and LED in the OSEM assemblies. I connected an idc breakout board to J4 and powered the |
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Wed Feb 24 10:23:03 2021, Yehonathan, Update, SUS, OSEM testing for SOSs
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Continuing with the new rig, I measure the resistance of the cable leading to the coil to be 0.08+(0.52-0.08)+(0.48-0.08)=0.9ohm.
S/N
Coil Resistance |
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Wed Mar 3 11:51:07 2021, Yehonathan, Update, SUS, OSEM testing for SOSs
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I finished testing the OSEMs. I put all the OSEMs back in the box. The OSEMS were divided into several bags. I put the OSEM box next to the south flow
bench on the floor.
I have uploaded the OSEM catalog to the wiki. I will upload the LED spot images later. |
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Tue Mar 9 14:30:22 2021, Yehonathan, Update, SUS, OSEM testing for SOSs
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I finished ranking the OSEMS on the OSEM wiki page.
I also moved the OSEM data folder from /home/export/home to /users/public_html and created a soft link instead. I have done the same for the
40m_TIS folder that I uploaded there a while ago. |
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Tue Mar 9 18:49:28 2021, Yehonathan, Update, SUS, OSEM testing for SOSs
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29 Good OSEMs, of which 1 is questionable (089) with PD voltage of 1.5V, 5 need some work (pigtailing, replace/remove/add screws). We have 4 pigtails.
Schematics.
20 OK OSEMs (Slightly off-centered LED spot), of which 3 need some work (pigtailing, replace/remove/add screws). |
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Tue Mar 16 14:37:36 2021, Yehonathan, Update, BHD, SOS SmCo magnets Inspection
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In the cleanroom, I opened the nickel-plated SmCo magnet box to take a closer look. I handled the magnets with tweezers. I wrapped the tips of the tweezers
with some Kapton tape to prevent scratching and magnetization.
I put some magnets on a razor blade and took some close-up pictures of the face of the magnets on both sides. Most of them look like attachment |
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Wed Mar 17 14:40:39 2021, Yehonathan, Update, BHD, SOS SmCo magnets Inspection
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Continuing with envelope number 2
Magnet number
Magnetic field (kG)
1
2.89
2
2.85
3
2.92
4
2.75
5
2.95
6
2.91
7
2.93
8
2.9
9
2.93
10
2.9
11
2.85
12
2.89
13
2.85
14
2.88
15
2.92
16
2.75
17
2.97
18
2.88
19
2.85
20
2.87
21
2.93
22
2.9
23
2.9
24
2.89
25
2.88
26
2.8 |
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Thu Mar 25 12:11:53 2021, Yehonathan, Update, CDS, c1auxey assembly
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I finished prewiring the new c1auxey Acromag chassis (see attached pictures). I connected all grounds to the DIN rail to save some wiring. The power
switches and LEDs work as expected.
I configured the DAQ modules using the old windows machine. I configured the gateway to be 192.168.114.1. The host machine still needs to be |
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Thu Mar 25 14:58:16 2021, Yehonathan, Update, BHD, SOS SmCo magnets Inspection
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Redoing magnet measurement of envelope 1:
Magnet
#
Max Magnetic Field (kG)
1
2.89 |
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Fri Mar 26 10:25:37 2021, Yehonathan, Update, BHD, SOS assembly
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I measure some of the dowel pins we got from Mcmaster with a caliper.
One small pin is 0.093" in diameter and 0.376" in length. The other sampled small pin has the same dimensions.
One big pin is 0.187" in diameter and 0.505" in length. The other is 0.187" in diameter and 0.506" in length. |
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Tue Mar 30 17:27:04 2021, Yehonathan, Update, CDS, c1auxey assembly
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{Yehonathan, Jon}
We poked (looked in situ with a flashlight, not disturbing any connections) around c1auxex
chassis to understand better what is the wiring scheme. |
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Tue Apr 6 15:42:57 2021, Yehonathan, Update, BHD, SOS assembly
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We got some dumbells from Re-Source Manufacturing (see attached). I picked 3 in random and measured their dimensions:
1. 0.0760" in diameter, 0.0860" in length
2. 0.0760" in diameter, 0.0860" in length |
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Fri Apr 9 20:54:54 2021, Yehonathan, Update, BHD, SOS assembly
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Today I assembled the skeleton of 6 towers, without clamps and sensor assembly (attachment 1).
Some of the side plates have this weird hole that doesn't fit any of the suspension blocks (attachment 2). I didn't notice when I counted
the parts and now there are exactly enough side plates to assemble 7 towers. |
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Mon Apr 12 17:30:11 2021, Yehonathan, Update, BHD, SOS assembly
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Today, I screwed the plungers on the sensor plates and installed them on the Towers. I also installed the wire clamps on the suspension blocks (attachment).
I ran into problems in 2 separate suspension blocks: one had a dowel pin that was slightly too fat for the wire clamp. In another, the
tapped holes were too short so that the 4-40 screws couldn't be screwed all the way. |
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Mon Apr 12 18:34:26 2021, Yehonathan, Summary, PSL, PMC unlocked at 2pm on Sunday; ~ Restored
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PMC lost lock again at around 16:00 April 12. I was able to lock it again but the transmission is only 0.6 now and REFL is 0.14.
Rana
came in and realigned the PMC stirring mirrors. Now the transmission is 0.757V, and the REFL is 0.03V. |
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Tue Apr 13 20:45:16 2021, Yehonathan, Update, PSL, Laser amplifier
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{Yehonathan, Rana}
We unpacked the content of the amplifier crate in front of the water fountain (see attachments). Inside we found:
1. Amplifier head. (attachment 1) |
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Thu Apr 15 09:46:24 2021, Yehonathan, Update, PSL, Laser amplifier
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Some more relevant documents provided by Matt:
Phase III:70W amplifier integration at LIGO
70W amplifier External Shutter |
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Fri Apr 16 10:58:16 2021, Yehonathan, Update, General, Glue Freezer completely frozen
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{Paco, Anchal, Yehonathan}
We emptied the fridge and moved the amplifier equipment on top of the amplifier crate. We unplugged the freezer and moved it out of the lab to
defrost (attachment). |
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Fri Apr 16 18:21:36 2021, Yehonathan, Update, PSL, Laser amplifier
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I surveyed a bit the 1X1/2 area to plan for the installation of the laser amplifier.
There is a vacancy at the bottom of 1X2 (attachment 1). I measured the dimensions of the diode box (DB) and it should fit. The optical fiber
bundle is 75m long and should reach the amplifier head on the table easily. |
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Fri Apr 16 19:07:31 2021, Yehonathan, Update, General, Glue Freezer completely frozen
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There is still a huge chunk of unmelted ice in the fridge. I moved the content of that fridge in the main fridge and put "do not eat" warning
signs.
I returned the fridge to the lab and plugged it back in to prevent flooding. |
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Mon Apr 19 10:52:27 2021, Yehonathan, Update, General, Glue Freezer completely frozen
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{Anchal, Paco, Yehonathan}
We took the glue fridge outside. |
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Mon Apr 19 19:40:54 2021, Yehonathan, Update, General, Glue Freezer completely frozen
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{Paco, Yehonathan}
We broke the last chunk of ice and cleaned the fridge. We move the fridge back inside and plugged it into the wall. The glues were moved back
from the main fridge. |
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Mon Apr 19 21:54:55 2021, Yehonathan, Update, CDS, Updated c1auxey wiring plan
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Except for the feed-throughs that require a DB9-M connector I finished wiring and labeling the Acromag, following Jon's updated wiring plan.
We can start testing the differential inputs until the missing connectors arrive.
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Thu Apr 22 17:28:34 2021, Yehonathan, Update, PSL, Laser amplifier
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According to the aLIGO 70W amplifier interlock concept the flow rate of the chiller should be between
5 and 40 l/min. The chillers I found in the TCS lab both have around 15 l/min flow rate so we should be fine in that regard.
Assuming that the power consumption of the diode box is ~800W and that the optical output power of the diode is ~ 300W of optical power, the |
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Thu Apr 29 16:35:51 2021, Yehonathan, Update, CDS, Updated c1auxey wiring plan
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I installed the EPICs base, asyn and modbus modules according to Jon's instructions.
Since the modbus configurations files were already writtten for c1auxey1 (see elog 15292)
the only thing I did was to change the IP addresses in ETMYaux.cmd to match the actual assigned IPs. |
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Thu Apr 29 19:55:45 2021, Yehonathan, Update, CDS, Updated c1auxey wiring plan
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We received a stock of DB9 male feed-through connectors. That allowed me to complete the remaining wiring on the c1auxey Acromag chassis. The only thing
left to be done is the splicing to the RTS.
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Mon May 3 16:49:04 2021, Yehonathan, Update, BHD, SOS assembly
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I found a "vice" in the cleanroom (attachment 1). I used it to push dowel pins into the last suspension block using some alcohol as a lubricant.
I then assembled the 7th and last suspension tower (attachment 2).
Things that need to be done: |
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Tue May 4 19:14:43 2021, Yehonathan, Update, General, OSEMs from KAGRA
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| I put the box containing the untested OSEMs from KAGRA near the south flow bench on the floor. |
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Tue Jun 1 16:17:06 2021, Yehonathan, Update, BHD, SOS assembly
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I tried to push the clean Viton tips into the vented screws just to find out that the vented holes are too small. We need to drill 0.1" diameter
holes about 0.1" deep into these screws and clean them again.
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Thu Jun 3 17:15:17 2021, Yehonathan, Update, CDS, Opto-isolator for c1auxey
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As Jon wrote we need to use the NPN configuration (see attachments). I tested the isolator channels in the following way:
1. I connected +15V from the power supply to the input(+) contact.
2. Signal wire from one of the digital outputs was connected to I1-4 |
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Fri Jun 4 14:49:23 2021, Yehonathan, Update, CDS, Opto-isolator for c1auxey
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I made a diagram (Attached). I think it explains the blue thing in the previous post.
I don't know what is the grounding situation in the RTS so I put a ground in both the coil driver and the RTS. Hopefully, only one of them
is connected in reality. |
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Sun Jun 6 15:59:51 2021, Yehonathan, Update, CDS, Opto-isolator for c1auxey
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According to the BO interface circuit board https://dcc.ligo.org/D1001266, PCIN wires are connected to the
coil driver and they are not pulled either way.
That means that they're either grounded or floating. I updated the drawing. |