[Michael R, Richard M, Alberto]
Richard and his contractor brough a PC/PC fiber into the PSL enclosure. Since Richard's fiber has a PC connector and the collimator's pigtail has an APC connector, we had to use an adapter made of a fiber with APC and PC ends.
Mark B and Jeff B. We stumbled across a nasty bug in the Matlab script plotHSTS_dtttfs.m. We were trying to generate plots for PRM data from 9/5/12 at 1900, but the script was failing to write the expected files. Eventually we realized it was writing files with "1300" for the time. This was because there was a line fileInfo = dir([dataDir '*' meas.yyyymmdd '*tf.txt']); which was intended to look for all files in the Data directory matching the date/time pattern specified in the settings at the top of the script. Unfortunately it omitted any reference to the time, which meant the subsequent search would always find the first dataset for the day. We changed it to match the equivalent HLTS script which has fileInfo = dir([dataDir '*' meas.yyyymmdd '_' meas.hhmm '*tf.txt']); and committed it as r3308. As far as past data goes, no raw data will have been corrupted. We _think_ all PDFs and any diagnoses and approvals based on them should be valid - even if data for some particular excitation DOF was read from a file with the wrong time, the resulting PDFs should have same time in their names, so the names would match the contents. However what was displayed in Matlab figure windows would sometimes have been old data if there was more than data set for the requested day. Also, a corrupt .mat file could conceivably have been generated if a partial data set was taken in the morning (e.g., only 3 excitation DOFs) and a full one in the afternoon.
[Michael R., Alberto]
We temporarily borrowed the 1064 Farady that was purchased by Bram for the ISCT1 table (ALS vertex) to install it before the fiber collimator on the PSL table.
After this addition, the power coupled into the fiber went down to 2.1 mW (was 3 mW) due to the induced beam shift. Unfortunately the current setup of the steering mirrors doesn't let us displace the beam by much: one fo the steering mirrors is out of hand reach and it's close to a high power beam.
We're still coupling more power from the PSL than ifrom the ALS refcav. So it should be okay, unless we're going to lose more than .5 mW downstream when we'll connect the new fiber going to the optics lab..
35W beam
From initial alignment data, we know the following:
Positive offset in PIT (H2:SUS-ETMY_M0_OFFSET_P and H2:SUS-ITMY_M0_OFFSET_P) will tilt the mirros such that the reflected beam off of the mirrors will go down.
Positive offset in YAW will tilt the mirrors such that the reflected beam off of the mirrors will go toward the inside of L.
That is, the upper stage of ITM looks like the mirror image of the ETM. Why is this the case? I thought that they are identical.
Also, I think oplev sign is somehow wrong. It's not consistent with initial alignment data.
FYI, the sign of the things in initial alignment was figured out by:
First using baffle diodes to figure out the sign of the TMS to figure out the TMS sign, and make the first beam hit the center of the ITM.
Then using ETMY cage and CCD camera, make the reflected beam from the ITM hit the cage bars to figure out the sign of ITM.
Then move offset of ETMY so that the beam comes back to the table, then move TMS and repeat, to see if ETMY sign is the same as TMS (it is).
As you can see, there is not much ambiguity there.
Attached is the oplev and upper stage offset. (Jumps not caused by the offset are from HEPI.)
For positive SUS offset, the following is true for Oplev:
| Positive PIT offset | Positive YAW offset | |
| ETMY | Oplev goes negative | Oplev goes positive |
| ITMY | Oplev goes positive | Oplev goes positive |
From this, oplev seems to think that positive PIT offset moves ETMY down but ITMY up, and positive YAW offset rotates both ETM and ITM in the same direction.
Mark Barton I did some followup on this issue and it looks as if the F2 and F3 OSEMs may be swapped on ITMy. See attached plots which have Keita's channels (divided up into separate plots for ETMy and ITMy), plus additional ones of interest, including the M0F1, M0F2, M0F3, L1UL and L1LR sensors, the estimated P and Y from the OSEM2EUL blocks at M0 and L1, and the requested drives to the M0F1, M0F2 and M0F3 coils before magnet sign correction. I also zoomed in on a 3 hour period from 12-09-06-02-00 to better show the events of interest. With ETMy, everything is as expected. The pitch OL reads negative for positive pitch offset but this is as designed - the OL is trying to be a measure of beam height and positive SUS pitch is down. (Yaw is left=positive viewing the QPD from the optic, which is the same convention as for SUS.) With ITMy, everything internal to SUS to do with pitch is as expected, but the OL does not have the expected opposite sign. In yaw, the M0 and L1 Y channels have opposite sign and the yaw OL agrees with M0 yaw. This would be consistent with the F2 and F3 OSEMs on the ITMy being swapped. A further data point in favour of this is that the signs in the ITMy COILOUTF block are the opposite of expected from E1000617 (F2 should be opposite F1 and F3, and is for ETMy, but it's F3 that's opposite for ITMy). This was earlier put down to a magnet swap, but the comparison with the L1 level suggests it's actually the OSEMs that are swapped. This wouldn't be a hard mistake to make because the convention in E1000617 is a bit confusing: both M0 and R0 face OSEMs are labelled F1 F2 F3 as viewed from the _back_ (i.e. the reaction chain side), so the M0 OSEMs are F1 F3 F2 from the side you would work on them from. As far as OL's are concerned, things are consistent with both ITMy OL channels being flipped, as if the QPD were upside down.
Mark B. Thomas V. We buzzed out the the QPD with a laser pointer on ITMy and found that the QPD is upside down from what the MEDM screen on the SUS quadrants are indicating. The segments of the QPD are laid out as such: +-------+ | 2 | 4 | ^ |---+---| | This way up | 3 | 1 | | +---+---+ I believe the error came from a miscommunication in the exchange of information between SUS and OptLevs. I had originally mapped out the quadrants on 07/24/2012 according to ALOG 3573 using the MEDM screens. I wasn't aware that the top level ITMY SUS QUAD model had been re-ordering the signals as such (as described in Jeff K's ALOG 3613): Analog Signal ADC Channel SEG# 1 1_0 SEG2 2 1_1 SEG1 3 1_2 SEG4 4 1_3 SEG3 According to ALOG 3613, Jeff had re-ordered ADC Channel and SEG# to 1:1 as it makes the most sense to be that way! I think this sequence of events led to us being confused on why the signals look like they're upside down since the diagonals of the signals are switched. This fix explains why Keita's original entry shows that the OptLevs look "backwards" in some sense. For future reference, I'll try to be more clear on what I'm measuring when mapping out the orientation of the optical lever QPD, as well as run tests with the suspension offsets in pitch and yaw to make sure they coincide with each other. This will be added to the Optical Lever Installation Procedure (E1200063).
M. Barton, J. Kissel, J. Shapiro, S. Stepleskwi Mark has spent a good bit of time, (a) creating a new parameter set of the QUAD model to represent the current, odd-ball main-chain of H2 SUS ITMY configuration (a wire hang of the a glass mass) called 'wirerehang' (originally reported in LHO aLOG 3017), and (b) while creating the awesome new QUAD model mode shape wikipages, discovered a few bugs in the reaction chain model parameter sets ('erm' and 'thincp'), and has fixed them. Here, I document these changes by (1) Comparing the updated model against the previous version (in the case of the reaction chain parameters), and comparing against what we would have used otherwise (in the case of the wire rehang models), (2) Comparing both models to representative measurements we have of each, and (3) Explaining / justifying the details of the parameters that have changed. For (1) and (2), see attached plots for each of the three updated models, and for (3) see the tables below. Note, only parameters that have changed are shown, and of those, only the changes in hard-coded (as opposed to derived/calculated from hard-coded) parameters are shown. As of this entry, the updates to ${SusSVN}/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production/quadopt_wirerehang.m ${SusSVN}/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production/quadopt_thincp.m ${SusSVN}/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production/quadopt_erm.m which are options for the buildType argument of the function ${SusSVN}/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production/generate_Quad_Model_Production.m which produces models all production analysis software suites have been committed to the svn, under rev 3304. Please svn up! Executive summary of changes: ----------------------------- Wire Re-hang Major Changes: - Changed sign of TOP ('n' stage) off-diagonal moments of inertia due to misinterpretation of coordinate system used in Final Design Document (though this has little affect on the predicted dynamics because the magnitude is small) Small Changes: - TOP ('n' stage) and UIM ('1' stage) mass weights ('m' s) and moments of inertia ('I' s) adjusted to reflect QUAD retrofits - Radius, mass and moments of inertia of TST ('3' stage) changed to reflect the (glass mass and prisms) vs. (metal mass and prisms) - Change of d's to better reflect measured pitch frequencies of (glass mass and prisms) vs. (metal mass and prisms) - PUM to TST horizontal separations ('n3', 'n4','n5') changed to match glass mass and prisms vs. metal mass and prisms - Spring stiffness ('k') updated to match Brett's 2010 fit to vertical TFs (vs. a prior, 2008 fit). From the plots: - Most features remain identical, and match up well with either the wire measurements or the one wire-rehang H2 SUS ITMY measurement. - As usual, Pitch, the most sensitive degree of freedom, is now better matched to the data, but have changed no more than 10%. - The changed parameters only affect Pitch dynamics, so the model hasn't changed, and still matches the data exquisitely. Thin CP Major Changes: - Changed sign of TOP ('n' stage) off-diagonal moments of inertia due to misinterpretation of coordinate system used in Final Design Document (though this has little affect on the predicted dynamics because the magnitude is small) Minor Changes: - UIM ('1' stage) mass weights ('m' s) and moments of inertia ('I' s) adjusted to reflect QUAD retrofits (specifically the pitch adjuster). From the plots: - Without lacing cables, the model continues to match the data extremely well. - With lacing cables, in L, T, V, R, and Y, there's still a bit of difference between the model and measurements, though only in stiffness as expected. The resonant frequencies still match just about as good without lacing cables. - Pitch, the DOF most affected by the lacing cables (who's surprised?) is the worst, but still, only the lowest two modes in frequency are increased (i.e. modeP1 and modeP2 which involve the TOP and UIM masses, which have the most lacing cables running through them). - Any and all remaining discrepancies between model and measurement are not of much concern, since this is a reaction chain which has no where near the control-noise performance requirements as the main chain, so we'll most likely rely on a simple set of damping filters that are robust against the differences. ERM Major Changes: - Corrected TST stage thickness, it had the Thin CP value (copy'n'paste oversight). - Changed sign of TOP ('n' stage) and PUM ('2' stage) off-diagonal moments of inertia due to misinterpretation of coordinate system used in Final Design Document (though this has little affect on the predicted dynamics because the magnitude is small) Minor Changes: - Updated TST stage moments of inertia for an ERM, as opposed to a Thin CP. From the plots: - For L,T,V,R, and Y, either model doesn't perfectly capture the changes brought on by lacing cables, or from switching from metal to glass -- specifically the increase in stiffness (from cables), and the bifurcation of the second trans mode -- but, as with the Thin CP, it's expected and not a big deal. - For Pitch, neither model gets the stiffness right, cables or no cables, though we should triple check this against other no-lacing cable, ERM chain measurements. Unclear why this is. Naturally, when you add lacing cables, the lowest resonant modes increase in frequency, but this is exactly the same as on a Thin CP, so it's understandable since they have the same cables, the same configuration of routing, and the mode shapes are the same (see modeP1 and modeP2 of the last version of the production models). - Any and all remaining discrepancies between model and measurement are not of much concern, since this is a reaction chain which has no where near the control-noise performance requirements as the main chain, so we'll most likely rely on a simple set of damping filters that are robust against the differences. Full details of parameter changes --------------------------------- Table 1: Wire Rehang 'Param' 'Former Production Value' 'Updated Value' 'Differnce' 'Difference' '' 'Model: wire' 'Model: wirerehang' '(Absolute)' '(Percent)' 'mn' '21.9' '22' '0.0696' '0.317%' 'Inyz' '4.65e-05' '-4.65e-05' '-9.3093e-05' '-200%' 'Inzx' '0.00172' '-0.00172' '-0.0034368' '-200%' 'm1' '22.3' '21.5' '-0.81226' '-3.64%' 'I1x' '0.509' '0.505' '-0.0040466' '-0.795%' 'I1y' '0.0711' '0.0724' '0.0013481' '1.9%' 'I1z' '0.518' '0.518' '0.00013532' '0.0261%' 'I1xy' '-0.0132' '-0.0132' '5.271e-06' '-0.0399%' 'I1yz' '0' '1.37e-05' '1.3742e-05' 'Inf%' 'I1zx' '0' '-8.08e-06' '-8.084e-06' '-Inf%' 'm3' '39.6' '39.6' '0.031' '0.0783%' 'I3x' '0.598' '0.568' '-0.029963' '-5.01%' 'I3y' '0.418' '0.42' '0.0011272' '0.269%' 'I3z' '0.4' '0.411' '0.010141' '2.53%' 'dm' '-0.00351' '-0.00353' '-2.2308e-05' '0.636%' 'dn' '0.00328' '0.00423' '0.00095167' '29%' 'd0' '-0.00174' '-0.00175' '-1.0004e-05' '0.575%' 'd1' '0.00299' '0.00399' '0.00099789' '33.3%' 'd2' '0.00709' '0.00708' '-4.0147e-06' '-0.0566%' 'd3' '0.001' '-0.00116' '-0.0021609' '-216%' 'd4' '0.001' '-0.00116' '-0.0021609' '-216%' 'n3' '0.176' '0.172' '-0.00425' '-2.41%' 'n4' '0.171' '0.172' '0.00075' '0.438%' 'n5' '0.171' '0.177' '0.00555' '3.24%' 'ln' '0.445' '0.449' '0.004192' '0.942%' 'l1' '0.311' '0.309' '-0.002415' '-0.777%' 'l2' '0.339' '0.331' '-0.008213' '-2.42%' 'l3' '0.604' '0.604' '0.00029403' '0.0487%' 'r1' '0.000355' '0.000356' '5e-07' '0.141%' 'kcn' '1.41e+03' '1.43e+03' '17.9919' '1.27%' 'kc1' '1.65e+03' '1.65e+03' '-1.8307' '-0.111%' 'kc2' '2.42e+03' '2.38e+03' '-40.5505' '-1.67%' 'kw3' '1.15e+05' '1.15e+05' '-56.022' '-0.0487%' Table 2: Thin CP 'Param' 'Former Production Value' 'Updated Value' 'Differnce' 'Difference' '' 'Model: thincp' 'Model: thincp_20120831' '(Absolute)' '(Percent)' 'I1y' '0.073' '0.0734' '0.00040601' '0.556%' 'I1z' '0.519' '0.518' '-0.00077135' '-0.149%' 'den3' '3.98e+03' '2.2e+03' '-1780' '-44.7%' 'Inyz' '4.36e-05' '-4.36e-05' '-8.7197e-05' '-200%' 'Inzx' '-0.00171' '0.00171' '0.0034279' '-200%' Table 3: ERM 'Param' 'Former Production Value' 'Updated Value' 'Differnce' 'Difference' '' 'Model: erm' 'Model: erm_20120831' '(Absolute)' '(Percent)' 'I1y' '0.073' '0.0734' '0.00040601' '0.556%' 'I1z' '0.519' '0.518' '-0.00077135' '-0.149%' 'tx' '0.1' '0.13' '0.02996' '29.9%' 'tr' '0.17' '0.17' '-1.5e-05' '-0.00882%' 'den3' '3.98e+03' '2.2e+03' '-1780' '-44.7%' 'I3x' '0.376' '0.376' '-6.6301e-05' '-0.0176%' 'I3y' '0.21' '0.225' '0.014932' '7.12%' 'I3z' '0.21' '0.225' '0.014932' '7.12%' 'Inyz' '4.36e-05' '-4.36e-05' '-8.7197e-05' '-200%' 'Inzx' '-0.00171' '0.00171' '0.0034279' '-200%' 'I2yz' '-2.38e-05' '2.38e-05' '4.751e-05' '-200%' 'I2zx' '-4.41e-05' '4.41e-05' '8.8146e-05' '-200%'
A couple of notes: * The CP and ERM models correspond to cases mark.barton/20120831TMproductionCP and mark.barton/20120831TMproductionERM of the Mathematica model. * Wiki pages for the CP and ERM models were generated on 9/11/12 and linked to from https://awiki.ligo-wa.caltech.edu/aLIGO/Suspensions/Background/QUAD/Models . * Also on 9/11/12, the resonance wiki page at https://lhocds.ligo-wa.caltech.edu/wiki/Resonances was updated with the new (but almost identical) mode frequencies. * The wire rehang model r3304 is based on Mathematica case mark.barton/20120601TMproductionTMrehang but has had one additional edit by Jeff K to supply a parameter pend.bd not used in the Mathematica. A new case to be called mark.barton/20120831TMproductionTMrehang that has the same MOI fixes as the CP and ERM updates is in the works.
Vincent finally made the HEPI and ISI behave, but I had a hard time realigning. TMS has a rather large offset in PIT which seems to be caused by HEPI incident.
Anyway, in the end I started over from scratch, centering on ITM using TMS and baffle diodes.
PD1 max (28500 counts) : TMSP=-92313, TMSY=26574
PD2 max (29300 counts): TMSP=-922420, TMSY=11355
PD4 max (29200 counts): TMSP=-54958, TMSY = 11817
I took the mid point of PD1 and PD4 and set TMS offset to (p,Y) = (-73636, 19196).
I used manual alignment followed by tdsdither to obtain this:
ETM: (P,Y)=(-3028.634, 5409.607)
ITM: (P,Y) = (5771.803, 761.433)
REFL_B_PWR went up to about 8100 counts, which is really good (remember, we inserted 10% pick off for WFS, which means that 8100 counts is equivalent of 9000 counts before the change).
However, WFS refuses to work. PIT just goes away even if I reduce the gain considerably. In an attempt to center WFS, one of the picos on the table might have dropped. I haven't looked at the table yet.
I'll leave it WFS-less for now.
Attached is the calibrated spectrum as of now (references are from Aug/25 (blue) and Aug/22 (green), respectively). Somehow 1/f-ish noise between 1 and 20Hz increased, though low frequency noise is good.
The file is here: /ligo/home/controls/keita.kawabe/OAT_2012/length_example_20120905.xml
The differences between now and then are:
1. Sensor correction is on now.
2. VCO to HEPI relief is off now because Vincent wanted to leave it that way.
3. Alignment is different (HEPI didn't go back exactly to the original position and relatively large realignment of cavity and TMS was necessary).
4. WFS path is different now though WFS is off.
I haven't checked the refcav status except that it is locked.
Note to self:
I first tried to align ETM and ITM using oplev, then moved TMS to steer the reflection back to the center of WFS. That was OK, transmission went up to 8000, but the WFS didn't behave and I got suspicious about the alignment.
Anyway, the alignment offset for that state was:
TMS(-68167, 17392)
ETM(-2802, 5014)
ITM(5945, 486)
If we believe that the old oplev positions are better, we need to go back to this.
Apparently the noise comes and goes.
Disregard the glitchy data (red and blue).
Attached are plots of dust counts > .5 microns in particles per cubic foot. Also attached is a plot of the mode of dust monitor 9 in the LVEA (in the clean room over HAM1 and HAM2) to show when it was started. The first initial spikes may be from my testing it (rubbing gloves, frock over it).
[Michael Rodruck, Alberto]
We continued the work started yesterday to pickoff the PSL reference cavity transmitted beam. We installed a PCLX-386.3 CVI lens ( f~750mm) between the two steering mirrors that we had already placed yesterday. The lens is to mode-match the beam into the fiber.
Initially we aligned the fiber coupler by using the guide beam provided by an OzOptics fiber-coupled laser. Then we improved the alignment by monitoring the power transmitted thorugh the coupler's pigtail.
The power coupled into the fiber is now 3.0 mW, which is more than 50% of the 5.5mW coming from the refcav and also more than twice the power that we currently couple into the fiber in the optics lab.
We also installed a flange on the PSL table with fiber connectors so that we can easily plug-in the new long fiber to the optics lab that is going to be installed tomorrow.
It would be nice if we could have also a Farady isolator to avoid scattered light from the fiber back into the refcav. I'm not sure if we have one available around.
The broken magnets on H1-PRM have been replaced and the suspension has been realigned. The first transfer functions showed rubbing. We found the upper right M2 magnet rubbing on the flexi circuit in the AOSEM. We rechecked and adjusted as necessary all remaining OSEMs, and reran the transfer functions. They did not look good, but there were assembly activities underway in the staging building. I will rerun the transfer functions tonight when the building is quiet.
[Alex, Cheryl, Deepak, Giacomo]
Yesterday, all ECDs have been set in place (position "2", i.e. 2 x 0.025" feeler gauges between magnet holder and bracket).
DC pitch of all optics has been set to 0 +- 0.5 mrad, except IM4 (set to pitch up by 4 +- 0.5 mrad).
All OSEMs have been centered, with the connectors (and the LED-PD line) in vertical, away from the optical axis. Although their relative position to the optic moved by some 50 um when we moved the suspensions in different positions on the table, clamped them and put the barrel on, all OSEMs can be set to read less than about 10 um by applying suitable offsets (basically showing that the "butterfly misalignment" is of this order). See data just after 17:45 local time on September 4.
We took TFs between about 6:00 and 7:30 pm yesterday, OSEMs' offset set to keep them centered and minimize non-linearities. Then left the suspensions undamped (but with offsets on) for the night. TFs and PSDs starting at 10:00 pm last night are attached.
Today I have spent most of the day trying to do a ringdown measurement on bounce, roll and transverse. I drove the "butterfly" mode at the frequencies previously measured for this mode, exploiting the parasitic coupling to excite them. I was able to excites all the modes, but I haven't had time to analyze the data yet. This are the relevant times for the excitations:
2012-09-05 12:28 Switching on "butterfly excitation" on IM1 and IM2. Amplitude = 10000 (per coil), frequency matching the measured one for bounce.
2012-09-05 12:50 Switching off excitation. Let it ringdown...
2012-09-05 13:57 Switching on "butterfly excitation" on IM3 and IM4. Amplitude = 10000 (per coil), frequency matching the measured one for bounce.
2012-09-05 13:19 Switching off excitation. Let it ringdown...
2012-09-05 13:32 Switching on "butterfly excitation" on IM1 and IM2. Amplitude = 10000 (per coil), frequency matching the measured one for roll.
2012-09-05 14:15 Switching off excitation. Let it ringdown...
2012-09-05 14:25 Switching on "butterfly excitation" on IM3 and IM4. Amplitude = 10000 (per coil), frequency matching the measured one for roll.
2012-09-05 14:47 Switching off excitation. Let it ringdown...
2012-09-05 14:55 Switching on "butterfly excitation" on IM1 and IM2. Amplitude = 10000 (per coil), frequency matching the measured one for trans.
2012-09-05 15:22 Switching off excitation. Let it ringdown...
2012-09-05 15:30 Switching on "butterfly excitation" on IM3 and IM4. Amplitude = 10000 (per coil), frequency matching the measured one for trans.
2012-09-05 15:50 Switching off excitation. Let it ringdown...
After the last measurement we removed the barrel and moved the HAUX in the middle of the table to make some space for HxTS testing.
Modifications to the old enclosure on the 'SMART TABLE UT2' in the LVEA laser lab area are complete (see picture 1). There were several components missing on this enclosure when I arrived that could not be located which I borrowed from the enclosure currently on the IOT1 table (bottom of the two stacked enclosures). These include angle brackets, 3 panels, and some panel bolts. This newly modified enclosure will serve as that for IOT1. The new 3' x 5' table, legs, and enclosure to serve as IOT2 have been assembled and is resting outside of the LVEA laser lab area. I noted that the new enclosures do not include the cable tray system that is being installed on the modded enclosures. I used the cable tray system intended for LIGO India's IOT1 enclosure and modified it to fit in the IOT2 enclosure. I unpacked and stowed the Light Pipe assembly inside the IOT2 enclosure awaiting install.
Valved-out aux. cart for overnight -> Will valve-in and continue tomorrow. I expect the ion pump to come on scale after a day or two of this.
Foton GUI quietly discarded (some of?) notch filter definitions and replaced them with a flat gain of 1.
This is easily reproduced by first opening e.g. /opt/rtcds/lho/h2/chans/filter_archive/h2iscey/H2ISCEY_120828_143926.txt and saving it to some other file, e.g. test.txt, and take a diff (attached).
Probably because of this bug, all WFS notches are gone from current H2ISCEY filter file.
This is extremely worrisome.
It's not notches, it's zero ramp time.
bugzilla report of this:
https://bugzilla.ligo-wa.caltech.edu/bugzilla/show_bug.cgi?id=414
Jim Batch already found the cause of this (ramp time was zero for the filter), and is working on a future workaround. In the mean time, if you select "ramp" switching, don't forget to set the ramp time manually to something non-zero.
Noisy day, use of crane and forklift, lots.
