Today I set up the LASER_UP state which monitors the system once the locking is done. The power output and PZT voltage output are monitored and if they exceed allowed values guardian goes back to the FIND_LOCK_POINT state to try to find a new locking point.
I also added another assert class that monitors the chiller temperature setpoint throughout the locking process including the final LASER_UP state, so that the temperature set point doesn't run away to a value that can cause the chiller to trip off. When a chiller setpoint that is outside of the allowed range is detected it goes back to the DOWN state, resets the chiller setpoint and then starts moving back up through to LASER_UP.
Guardian has now also been set up for the X-arm laser, tested, and is now working.
Dave has taken a safe snap of the system in the DOWN guardian state to record new gain settings and the filter settings for when the servos are off.
Dave, Cao, Evan
We wanted to check briefly how the electronics noise of the PUM coil drivers compares to the excess noise in DARM.
With an SR785, we measured the voltage noise spectra out of the IX and IY coil driver chassises (going to the satellite boxes), and below 80 Hz we found them all to be below to the noise floor of the SR785 (40 nV/rtHz at 10 Hz, 10 nV/rtHz at 100 Hz). On the other hand, in order to explain a 1/f4 DARM noise of 1×10−19 m/rtHz at 30 Hz, this would require a white voltage noise at the coil output of 190 nV/rtHz for a single coil, or 50 nV/rtHz for 16 coils with uncorrelated noise.
If we want a good measurement (not just an upper limit) of this coil driver noise, we should use a FET-buffered preamp for reading out the signal.
While working through the SUSAUX medms (my previous entry), it became clear to many of us (Dave included) that the SUSAUX drop downs from the sitemap linked to old and unused screens. So, we removed them from the sitemap. I then reorganized the sitemap in a small way to cleanup. Most notably, IOO is now in it's seemingly more proper place under the left MAIN side of the sitemap.
Screenshot of new map. It has been committed to SVN.
Today, Kissel and I worked through completing the following (taken from ECR E1600033) for the SUSAUX QUAD and BS models. This meant recompiling and restarting h1susauxb123, h1susauxex, and h1susauxey with CDS and building new medms screens.
1) Remove SUS NOISE and VOLT MONs from all UPPER stages of SUSes, and non-globally controlled LOWEST stages, and replace with FAST_I_MONs with same data rate.
2) Remove SUS NOISE and VOLT MONs from frames of 10 SUSes under global control and replace with FAST_I MONs (or Fast LV ESD MONs where applicable) with increased data rate of 16k.
3) We will add associated filter banks for every FAST_I_MON.
Data rate calculations show that there will be a zero sum gain to the Science frames by performing the above (see supporting spreadsheet on DCC page).
New FASTIMON screens are shown below. All model and medm changes have been committed to the SVN.
Due to this change, when you try to look at LVESDAMON further back in time than this afternoon, DTT says "synchronization error".
This is where you can use the new feature of DTT.
Work continued with the install/cabling of the WFS Centering RF Triplexer electronics. - Powered up new Distribution Amp and whitening chassis - Installed some of the new RF cabling to the demod and Dist Amplifier. None of the existing cabling was disconnected - Routed the RF Monitor outputs of the I&Q Demodulator to the Demod Concentrator chassis
reported by Masayuki Nakano (I used this account because the firefox remembers it)
The new ISS second loop medm screen, '/opt/rtcds/userapps/release/psl/common/medm/ISS/PSL_CUST_SECONDLOOP.adl' has been made.
The privious screen is remained as '/opt/rtcds/userapps/release/psl/common/medm/ISS/SL.adl"
Filiberto removed Beckhoff Corner Chassis 4 from the CER. He added two EL3104 terminals at the end of the left rail and swapped the L10 EL9190 terminal for an EL9410 terminal. The two EL3014 terminals were already added to the system manager but disabled. I enabled them. I also added the EL9410 terminal and removed the EL9190 terminal. I checked that the changes matched a scan of the boxes and that an activate configuration worked. I saved the system manager file and committed it to svn (rev 2651). I then used Daniel's GUI to restart everything. I had to start PLC3 by hand. Last week I updated HartmannSensor.lib to add normalized position channels and committed it to svn (rev 2647). These channels are now available in EPICS: H1:TCS-ITMX_HWS_POSITIONDETECTOR1XNORM H1:TCS-ITMX_HWS_POSITIONDETECTOR1YNORM H1:TCS-ITMX_HWS_POSITIONDETECTOR2XNORM H1:TCS-ITMX_HWS_POSITIONDETECTOR2YNORM H1:TCS-ITMY_HWS_POSITIONDETECTOR1XNORM H1:TCS-ITMY_HWS_POSITIONDETECTOR1YNORM H1:TCS-ITMY_HWS_POSITIONDETECTOR2XNORM H1:TCS-ITMY_HWS_POSITIONDETECTOR2YNORM
Chassis S1107450 modified to wiring diagram E1101222-v2. This was to add readbacks for another AS demod chain.
Dave restarted the DAQ to add these channels to the frame.
~1535 1555 hrs. local -> To and from Y-mid Next over-fill to be Thursday, Feb. 4th before 4:00 pm
The articulating boom lift, (10,000 lbs.) is blocking the walk way at the corner near HAM 3 & 4. You could climb over the tire, however, the preferred route would be around HAM 1.
The boom lift will need to be moved several more times along the walkway it is in currently. The crane rail that is being shimmed needs to be done in steps which require multiple supports to be unbolted simultaneously. Some bolts remain in the loosened supports for safety.
DaveB rebooted the ASC model for me earlier today. I have confirmed that all of the signals go through the matrices as I expect.
I have also copied antiwhitening filters into the individual segment filter banks of the new AS 90 WFS, and loaded the whole ASC Foton file
Tomorrow morning, Elli, Cao and I will go with Rich and Fil to measure the relative phase between the I and Q channels of each segment. After that, we should be ready to start using the new AS 90 channels (setting the analog gain and whitening, digital demod phasing, etc.).
WP #5710
I have added two functions in the PSL ISS front end model. Both are related to the second loop and not to the first loop. The model has been compiled, installed and restarted. The changes I made are:
I have not yet tested these functions. Since the changes are additive to the existing model, one can still use the guardian to engage the second loop.
The attached is a half-baked and inaccurate medm which shows the new functions. Even though it is inaccurate, it is conceptually good enough to show what I implemented.
The trigger logic is shown in the right hand side of the screen. It watches the amount of the signal (i.e. SECONDLOOP_SIGNAL) which would go to the inner loop and triggers the second loop when it meets the trigger setting.
The software AC coupling function is show in the left of the screen. When one wants to keep using the manual silder to adjust the offset, one can fill the first row of the matrix which plugs the slider value to the offset point. When one wants a slow servo as the guardian has been doing, one can plug three different error signals and correct the offset point depending on the engagement steps.
Currently, Masayuki is editing the screen.
I finally managed to get the HWS TECs working on the superluminescent diodes. The problem was that the trimpots on the LDTC0520 drivers were not set correctly. Per page 11 of the manual, for a SLED with a thermistor and a TEC, we use trimpot LIM_A to set the cooling current limit and LIM_B to set the heating current limit.
The actual temperature on the SLED now goes to the set point temperature.
The temperature and humidity data for the long term storage Dry Boxes, and Desiccant cabinet. No apparent problems or issues noted with these storage boxes.
For a while I've been trying out sensor correction from the St1 T240s to the St2 CPS's, in X&Y. I thought this was working at ETMY, but not at ETMX, on closer inspection this seems to be not true. Looking into the model with Dave and JimB, we found that the wrong signals are being sent to the X and Z CPS, but Y is okay. It turns out the X CPS is getting the RZ T240, Y is receiving the Y T240, and Z is getting the X T240. Attached image shows the problem area, circled in red. The T240 signals in the T240 bus to St2 are inverted, the bus is labeled X, Y and Z, but if you follow the wires from the T240 cart matrix they go to RZ, Y, X, as I noted. Even worse, the X CPS is receiving not only the T240 RZ, it's receiving the T240 signal before we subtract the Z drive coupling. No wonder X didn't work.
I'm going to file a work permit, fix the bug and let the rest of the SEI group discuss when LLO should get the fix.
Attached are spectra comparing the SUS ETM L3 LV ESD channels from lock segments before (Jan 24, 2016 03:35:00 UTC) and after (Feb 1, 2016 01:50:00 UTC) the ESD Driver update last Tuesday alog 25175 (and the subsequent ESD fixes on Wed 25204). Before the install, the channels looked like ADC noise, while they look live now. The ETMx plot is included, but of course the ETMx ESD is not ON during either lock stretch, so all the plot really says is that something happened to the channels. Whether or not the ETMy channels look like they actually should, according to various ECRs, is to be determined.
Keita helped me make more useful plots to evalute the new LV chassis mods. See attached.
The alog that motivated all of these is alog 22199.
In Betsy's new plots, reference traces are with the old hardware, current traces are new, both in full low noise lock. In summary, this is good.
The spectrum/coherence plot shows that the new whitening is useful, the monitor is actually monitoring what we send rather than just ADC noise. (It used to be totally useless for f>7Hz or so as you can see from the reference coherence.) You can also see that there's a small coherence dip at around 30Hz, and there are deeper dip at around various band stop filters, but otherwise it's actually very good now.
In the second plot, you see Y channel spectrum together with X. Since we don't send anything to X during low noise lock, X is just the sensing noise. When you compare the signal (red) and the sensing noise (light green), we can see that the signal is larger than the noise across the entire frequency range except the stopbands.
At around 30Hz (where we saw a tiny coherence dip in the first plot) the noise is only a factor of 3 or 4 below the signal. We expect the higher frequency drive above f=100Hz to drop as we increase the power, so the signal/noise ratio there might drop in the future. There's still a large headroom before we rail the ADC (RMS is 600 counts), so if necessary I'm sure we can make some improvement, but this is already very good for now.
The only thing is, what's these lines even when we don't send anything (X)?
It seems as if 57Hz and harmonics, whatever they are, in the non-driven channel are at least as large as in the driven channel.
57Hz was the HWS at the end stations.
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=25383