Date: Thu, 02 Sep 2010 16:56:49 -0500 From: "John E Anderson Jr." Subject: RE: 2.5m obslog 20100901 (MJD 55441) Hello Dan and Jim, From what you are describing, it sounds like the MCP has the desired position being sent to the servo amplifiers. When you depress the stop button, the telescope moves slightly if it is out of balance. When you re-enable the amplifier, the amplifiers are attempting to immediately move the telescope to the last desired position being sent to the amplifiers. However this should not cause a slip. Were the drive motors removed and replaced during the shutdown? If so the tension on the drive may not be set correctly. John -----Original Message----- From: Dan Long [mailto:long@apo.nmsu.edu] Sent: Thursday, September 02, 2010 4:31 PM To: jeg@astro.princeton.edu Cc: long@apo.nmsu.edu; obs-report-25m@apo.nmsu.edu Subject: Re: 2.5m obslog 20100901 (MJD 55441) Hi Jim, Yes, the telescope moves between the time a stop button is pressed sending the amplifiers out of closed loop and the time the brake engages. The error built up is proportional to how out of balance the telescope is. When in balance it is a few hundred ticks. If it is far enough out of balance that it has to push up to go down or push down to go up (more than about 25 counterweight units), it can drift more than 100,000 ticks. The slips tend to occur when the error is larger than about 30,000 ticks. Why there should be an attempt at correction when going into closed loop is mystery to me. I would have thought that by definition the servo error should be zero when entering closed loop, but apparently that is not the case. Another mystery is why this seems to have started causing slips post shutdown when it didn't before the shutdown. Could the acceleration parameters have changed with work over the summer? I am not familiar with where this information is stored. Is it in a file read in by the mcp at boot time? Cheers, Dan >It sounds very much like the telescope is drifting away and then >must do a very large acceleration to zero the servo error to its >desired position. I believe this is a bug, but it is not clear >whether it is hardware or software. At the very least, we need >to review the acceleration limits and be SURE that accelerating at those >limits does not cause slips. If it is drifting, it must be either >that it is doing so after the amplifiers are disabled but before the >brake comes on, OR that somehow the position information is being >clobbered, so there is a built-in `software' servo error when the >servos turn on. > >--jim > >On Thu, 2 Sep 2010, Kaike Pan wrote: > >> >> APACHE POINT OBSERVATORY SDSS 2.5M >> >> OBSERVING LOG >> Wednesday September 1, 2010 >> >> (MJD 55441) >> >>---=== OBSERVING TEAM ===--- >> >>Alaina Shelden >>Kaike Pan >> >>French Leger (support) >> >> >>---=== OBSERVING PLAN ===--- >> >>BOSS and MARVELS >>---=== OBSERVING SUMMARY ===--- >> >>Observed >>Two boss plates: >>cart 17, pl 4066. not quite done yet. >>cart 11, pl 4083. Done. S/N^2: 18.1 (b1), 35.5 (r1), 16.1 (b2), 30 (r2). >> >>Four marvels plate: >>cart 1, pl 3632B. Possible broken fiber: 67/68 >>cart 4, pl 3703A. >>cart 6, pl 3706A Possible broken fibers: 63/64, 87/88 >>cart 6, pl 3706B. possible broken fiber: 87/88 >> >>Note: We left alt bypass on. >> >>Problems: >>1. We had 2 altitude slips on motor #1 at 6 degree when we opened (see log). >>Later, we stuck at 67, and 56 degree (with alt slip bypass on) degree with >>altitude slips. We had to bypass the alt slip. We noticed that "axis init" >>moved the telescope up by ~ 1 degree, a few times but not always. about 60 >>minutes was lost to the problem that occured four times. >> >>2. Had phaseReboot. 5 minutes lost to it. >>3. Guider and gcamera crashed once. 5 minutes lost to it. >>4. GotoField failed on hartmann because sosActor is not connected? >>5. Cartridge 16 plugged but not in the plateDB, mapped? >>6. Heard rotator vibration sound once when slew to instrument change. >> >> >>---=== OBSERVING LOG ===--- >> >>Afternoon: >>---------- >>All systems and actors checked. SosActor is not connected. Restarted it >>from stagemanager did not help. Stagemanger says it is running but >>can not connect to hub. Sent a message to Craig, Fritz etc. >>00:30Z mounted cartridge 16 to check spectra position variations among >>cartridges. >> >>Cartridge 16 (plate 4231) was plugged today but is is not in the >>plate database. >>Has it be mapped? >> >>00:00Z started ventilation. >> >> >>Night: >>------ >>01:35Z enclosure off >>We had two altitude slips at 6 deg with "axis init". At that time, the >>counterweight was at 275. The telescope is slightly bottom heavy. The >>first three "axis init" did not anything (at least we did not notice). >>Then we checked and found All slip on motor #1. Reset it, "axis init" sent >>the telescope to 7 degree and had another alt slip on #1 again. Reset worked >>this time. >> >>02:15Z cartridge 17, plate 4066. sop gotoField failed on hartmann. >>02:30Z and 02:35Z We had a serious alter "phaseReboot on Sp2". But bias taken >>after the first warning seems okay. Play safe we issued a set of commands: >>clearExposure disconnectted, reloaded controllers, iack, clearExposure, bias. >>02:40Z Guider actor and gcameraICC crashed, restared from stageManager. >> >>03:00Z started science exposures. Clear sky with decent seeing, 1.0-1.4" by >>the guider and 0.9" by DIMM. >>We obtained 4 15-min exposures on this plate. It is NOT done. >> >>04:10Z cart 11, plate 4083. Full hartmann was done since hartmann >>on gotoField >>failed on the previous plate. SOGTF. >>04:30Z started science exposures. Clear sky with good seeing (1.1-1.5"). >>5 15-min science exposures were obtained. The plate was DONE. >> >>05:45Z started MARVELS calibs >>05:55Z cart 1, plate 3622A. We stuck at alt=67 degree with alt #1 slip. We >>cleaned both altitude surfaces, tred many times "reset slip + axis >>init". That >>did not help. Every time, the axis clear for one second and came >>back wight on. >>We also noticed that "axis init" moved the telescope up by ~ 1 degree a few >>times. After these attempts, We woke French up, he let us to bypass the alt >>slip. 35 minutes lost. >> >>06:30Z MARVELS calibs. >>T06:25:50.670.fits TIO 46305.555 5063.2754 >>T06:27:55.910.fits THAR 326.63126 740.70355 >>T06:32:30.290.fits TIO 46297.777 5057.6924 >>06:40Z switch to B field. Clear sky with 1.4" seeing. >>T06:47:35.650.fits STAR 40.554668 1118.9559 >>possible broken fiber: 67/68. >> >>07:39Z calibs >>T07:39:27.570.fits TIO 48549.668 5349.5283 >>T07:41:32.870.fits THAR 342.95001 760.18677 >>T07:46:07.370.fits TIO 48614.668 5363.1377 >>During slowing to the instrument change, Kaike heard rotator vibration >>sound. >>07:42Z cart 4, plate 3703. SOGTF. >>07:53Z started science exposure. Thin clouds with okay seeing 1.5-2.0". >>T07:53:49.290.fits STAR 28.686666 895.77496 >> >>08:45Z calibs. >>T08:45:36.690.fits TIO 46871.891 5176.6802 >>T08:47:43.220.fits THAR 331.76874 749.92462 >>T08:52:18.010.fits TIO 46697.891 5173.8188 >>08:50Z cart 6, pl 3706A. SOGTF. Thin high clouds with okay seeing (1.5-2.0"). >>09:30Z The tracking aborted due to a altitude slip (even with altitude slip >>bypass!) at 56 degree. This exposure is actually 40 minutes one. >> T08:55:26.190.fits STAR 20.542999 765.79511 >> Possible broken fibers: 63/64, 87/88. >> >>09:47 calibs. >>10:00Z did more altitude surface cleaning. The surface at SP1 side was >>extremely dirty. Another 30 minutes was losted to the problem. >> >>10:15Z another set of calibs. >>T10:14:36.190.fits TIO 45697.555 5057.2358 >>T10:16:41.570.fits THAR 324.14999 741.86438 >>T10:21:15.930.fits TIO 45724.109 5058.4243 >> >>10:20Z cart 6, 3706B. SOGTF. >>10:35Z started 50 min science. Cloudy sky with bad seeing 1.5-2.0" seeing. >>T10:33:35.020.fits STAR 31.530333 >>Possible broken fiber: 87/88. >> >>11:25Z calibs. >>T11:25:33.650.fits TIO 45609.668 >>T11:27:38.990.fits THAR 322.98126 >>T11:32:13.430.fits TIO 45803.223 >> >>11:35Z enclosure on. >>11:43Z endNight finsihed. >> >> >> >>---=== IMAGING RUN SUMMARY ===--- >> >>Run Time Stripe Lambda Last Flavor Comments >> Start End Begin End Frame >>------------------------------------------------------------------------- >> >>---=== IMAGING RUN DETAILS ===--- >> >> >>---=== SKIPPY RESULTS ===--- >> >>Run Frame nFrames stars muErr muRms nuErr nuRms rot az el >>--------------------------------------------------------------------------- >>---=== LTMATCH RESULTS ===--- >> >>Run Field nFields alt az nGood rowMean rowSig colMean colSig rot >>------------------------------------------------------------------------ >>---=== SPECTROSCOPY DATA SUMMARY ===--- >> >>Summary Checked (y/n): >>QA Procedures Done (y/n): >> >> UT Exp Time flavor comment (S/N)^2 totals >>========================================== b1 r1 b2 r2 >> >>---=== TELESCOPE OFFSETS AND SCALE I ===--- >> >>Time Instrument Az Alt Rot Scale >> pos offset pos offset pos offset >>------------------------------------------------------------------------------ >>04:43Z 11 33.89 0.0000 56.20 0.0000 207.95 0.0000 1.000160 >>07:00Z 1 0 231.72 0.0000 50.80 0.0000 84.64 0.0000 1.000430 >>09:02Z 6 0 290.18 0.0000 63.49 0.0000 122.41 0.0000 1.000410 >> >>---=== TELESCOPE OFFSETS AND SCALE II ===--- >> >> >> >>---=== FOCUS LOG ===--- >> >> setmir piston Temp Wind >>Time Inst scale M1 M2 Foc Az Alt (C) MPH Dir >>filt fwhm >>------------------------------------------------------------------------------ >>04:43Z 11 1.00016 -1580 106 251 34 56.3 16.4 2 332 >>-- 1.5 >>07:00Z 1 0 1.00043 -4246 -2102 234 232 50.7 15.7 4 196 -- 1.4 >>09:01Z 6 0 1.00041 -4049 -1943 264 290 63.5 14.0 1 166 -- 1.6 >> >>---=== WEATHER LOG ===--- >> >> Wind >> Time Temp F Dewp F MPH Direction Dust DIMM Sky >> 01:44Z 62 39 7 302 (WNW) 321 1.0 clear >> 04:44Z 61 41 1 331 (NNW) 364 1.2 clear >> 07:01Z 60 45 4 196 (SSW) 366 1.5 thin high clouds >> 09:02Z 57 47 1 166 (SSE) 402 1.6 thin clouds >> >> >> >>---=== TELESCOPE STATUS ===--- >> >>00:00Z - Began ventilation. Doors and louvers opened, fans on. >>01:35Z - Enclosure off. >>11:35Z - Enclosure on, doors and louvers closed, fans off. >> >>Alt slip bypassed on. >> >>Status at: 11:50Z >>Telescope stowed at: 30,121,00 mount >>Instrument mounted: 6 Cartridge >>Counterweights at: 280 lbs >>LN2 autofill systems: Connected and turned on. >>180L LN2 dewar scales: SP1 216 lbs, 18 psi >> SP2 231 lbs, 17 psi >> >> >>---=== SOFTWARE USED ===--- >> >>TPM: tpm_v3_5_0 >> >> >>STUI: 1.0b2 2010-07-21 >>alerts: trunk+svn114742 >>apo: trunk+svn114701 >>boss: trunk+svn115542M >>boss.daq: 1.2.14 >>boss.specMech: 3.0.1 >>gcamera: v1_1_2 >>guider: v1_0_20h >>hub: Tag: UNTAGGED_REVISION 502:504M >>mcp: v6_6_5 mcp.plc: 25 >>platedb: v1_0_5 sop: v1_1_3 >>tcc: 2.13.0 >> >>sdssProcedure(sdss3): v3_06 >>idlspec2d (sos3) --- v5_4_12 >>plate-mapper3 ------ NOCVS:v5_0_7 >> >>---=== MIRROR NUMBERS ===--- >> >> >>PRIMARY: >>-------- >>Scale: 1.000000 >> >>MIGS TONIGHT NOMINAL >>Axial A -5.5090 -5.5100 >>Axial B 16.0920 16.0940 >>Axial C 15.9200 15.9220 >>Trans D 11.0050 11.0100 >>Lateral E 10.6680 10.6553 >>Lateral F 12.2555 12.2301 >> >>GALILS >>Commanded: 10600. -250. 5800. 10250. 13050. 12650. >>Actual: 10600. -250. 5800. 10250. 13053. 12647. >> >> >>SETMIR VALUES >>PriDesOrient: 0.00 -13.67 10.53 574.80 742.37 >>PriOrient: 0.00 -13.67 10.53 574.80 742.37 >> >>SECONDARY: >>---------- >>Focus: 0.00 >>Air Temp.: 16.9 >>Alt.: 30.000001 >> >>MIGS TONIGHT NOMINAL >>Axial A -7.8340 -7.8320 >>Axial B -0.0350 -0.0410 >>Axial C 13.8170 13.8180 >>Trans D 14.1840 14.1840 >> >>GALILS >>Commanded: 1585406. 1566534. 1599019. -1450. -50. >>Actual: 1585350. 1566695. 1598880. -1462. -69. >> >> >>SETMIR VALUES >>SecDesOrient: 1257.00 -9.00 -4.00 -58.00 23.67 >>SecOrient: 1257.01 -9.08 -4.05 -58.12 23.37 >> >>---=== PROBLEMS IN DETAIL ===--- >> >> >> >>DSS DSS DSS DSS DSS Digital Sky Survey DSS DSS DSS DSS DSS DSS >>DSS *** The information posted to SDSS mailing lists is proprietary *** >>DSS This is message 5346 in the sdss-25mlog archive, URL >>DSS http://www.astro.princeton.edu:81/sdss-25mlog/msg.5346.html >>DSS The index is at http://www.astro.princeton.edu:81/sdss-25mlog/INDEX.html >>DSS To join/leave the list, go to >>DSS >>http://www.astro.princeton.edu:81/cgi-bin/mailinglists.pl/show_subscription?list=sdss-25mlog >>DSS To post a message, mail it to sdss-25mlog@astro.princeton.edu >>DSS >>DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS >> > >DSS DSS DSS DSS DSS Digital Sky Survey DSS DSS DSS DSS DSS DSS >DSS *** The information posted to SDSS mailing lists is proprietary *** >DSS This is message 5347 in the sdss-25mlog archive, URL >DSS http://www.astro.princeton.edu:81/sdss-25mlog/msg.5347.html >DSS The index is at http://www.astro.princeton.edu:81/sdss-25mlog/INDEX.html >DSS To join/leave the list, go to >DSS >http://www.astro.princeton.edu:81/cgi-bin/mailinglists.pl/show_subscription?list=sdss-25mlog >DSS To post a message, mail it to sdss-25mlog@astro.princeton.edu >DSS >DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS Digital Sky Survey DSS DSS DSS DSS DSS DSS DSS *** The information posted to SDSS mailing lists is proprietary *** DSS This is message 5348 in the sdss-25mlog archive, URL DSS http://www.astro.princeton.edu:81/sdss-25mlog/msg.5348.html DSS The index is at http://www.astro.princeton.edu:81/sdss-25mlog/INDEX.html DSS To join/leave the list, go to DSS http://www.astro.princeton.edu:81/cgi-bin/mailinglists.pl/show_subscription?list=sdss-25mlog DSS To post a message, mail it to sdss-25mlog@astro.princeton.edu DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS DSS