VLA Atmospheric Phase Interferometer (API) Maintenance History
Feb01-Aug01 Major upgrade to hardware. New 950 MHz LO card and circuitry. Increases stability dramatically. Also, fixed HVAC and installed temp monitor. Working reliably for months, with better behaved structure functions.
03Mar00 Log files in cactus/convert deleted (filled disk).
20Apr00 The API software generates huge log files in cactus/weather whenever there is a major problem, like power-outage. These fill-up disk and the software then fails.
10Feb00 New 940 MHz sweeping LO card installed. Heater fixed. Back on-line. by W. Dail
15Mar99 The STI/Phase Monitor RF chassis has been removed for repair. Right now it looks like a bad amplifier in the IF chain. Hopefully that's all that it is. VooDoo in progress... The STI/Phase Monitor will be down for another 3-4 weeks. Repair is in progress. Awaiting PCB's and parts. from W. Dail
15Mar99 Major upgrade of facility, including: new container for PC and electronics, weather proofing and re-dressing of wiring and cables, provide telephone interrupt of phase lock and for reboot of PC, fiber optic link for PC communications, redesign of user interface home page (watts, Dooley, Carilli).
99Jul16 Loss of signal due to adjacent satellite users: PLL board adjusted and 15 kHz filter installed in the loop.
98Nov03 Bug: History data runs off bottom of screen. Cannot be called back.
98Nov03 Begin Fiber installation.
98Nov01 Timing seems strange: non-unit records in RMS plot, and MST vs MDT in file creation history
98Oct23 Lightening strike. Down 3 days. Dooley reboot
98Aug24 Data collection stopped
98Aug20 2356 MST for unknown reason. PC rebooted today and data collection restarted. Carilli/Van Horn/Dooley
98Aug13 Attached test module: data collection returned to 1 sample/s. Reconnect to interferometer chassis: rate doubled. Signal @ pins 40 & 48 was only 2V P-P. Was 4V P-P with test module. Traced back to a 74ALS573 chip. Replaced chip and data rate now is normal 1 sample/s. Data are good from 1643 UT. Dooley
98Jun18 Data collection was interrupted for unknown reason and resumed at twice normal rate. Data are bad from 98jun18 to 98aug13. Roy
98Jun04 Down 1715 UTC until 2115 UTC: re-route the AC power into the enclosure, the door now has RFI gaskets, and the AC power cable is routed through a small hole in the side of the chassis, rather than through the front door. All cabling entering/leaving the enclosure have ferrite cloke filters clamped on to them. Hopefully, this will reduce the power level of the 40*N KHz RFI that Rick noticed in 4 band last January, and should close out maintenance item #25235. Mertley
98May20 Test whether the 61-s problem is caused by delay when writing file over network... write 15 min of data to local disc on PC (then restore writing to miranda) -> time intervals between records alternate 60, 61, 60, 61 s -> delay is reduced but not eliminated -> additional speed provided by fibre will help, but won't completely solve the problem. Is the remaining problem in Simon's LabView code? or in something to do with the PC setup? Dooley/Roy
98May15 Swapped in Lab-PC A/D card, sent from Tucson for test. Interferometer runs at normal rate. Interval between successive scans is 61 or 62 s, rather than 60 s. Perhaps due to pcAnywhere overhead? or overhead of writing to remote disk? or a remaining problem in the acquisition routine? Occasional 90-130s break between scans due to remote access? Update O/S with patches, swap back in original A/D card -> interferometer runs at normal rate. Dooley/Radford
98May13 Produced this page. Reconstructed history to this point from notes & emails. Roy
98May13 Found data logging running at 2x normal rate. Tests trace problem to A/D card configuration. Tests crash PC. Roy/Radford
98May12 Extensive help page update. Roy
98May4-8 Extensive display software update. Added coherence function plot, cycle-time recommendations, many cosmetic improvements. Folkers/Roy
98Apr24 PC hung. Rebooted. Dooley
98Apr24 Modified interf_conv.c to read 284 bytes of header instead of 266 as for labview v4. Roy
98Apr24 Found binary file format change between labview v4 & v5. Header contains 18 extra bytes in v5. Roy/Dooley
98Apr14 Data logging back up. Dooley
98Apr08 Data not logging to /home/miranda/phasemon. Dooley
98Apr03 Upgraded to LabView v5.0 from v4.01. Dooley
98Apr03 Upgraded PC motherboard. Dooley
98Mar30 Died for unknown reason. Dooley
97Nov24 Interferometer started producing four 800-kb dlg files per day from today. Reason? Roy
97Nov20 Changed disk on miranda for data logging. Dooley
97Nov12 Install tardis to keep PC clock close to UT. Dooley
97Nov12 Data breaks when hard disk accessed. Ordering faster disk. Dooley
97Nov12 Data breaks when PC is accessed over network. No fix at present. Dooley
97Oct22 Display software mods: remove solar balls, rescale wind speed & saturation rms phase plots, add line to structure function to show wind speed aloft. Folkers
97Sep24 Interferometer started producing seven 400-kb dlg files per day from today. Maybe A/D card configuration changed? Roy
97Sep24 Repaired A/D card installed. Dooley
97Sep18 PC hung; reboot. Petencin
97Sep16 Numerous display software mods. Fix daylight saving time bug. Folkers
97Aug14 Set up captive account on miranda for outside users to fire up displays. Milner/Roy
97Aug14 Replace dead A/D card with spare from Tucson. Dead card sent for repair. Dooley
97Aug12 A/D card dead; due lightning strike? Dooley
97Aug11 Solaris upgrade on miranda. Martin
97May29 VCO locked to wrong signal after cold night. Break lock & reacquire. Petencin
97May19-23 Install display software on miranda. Folkers/Roy
97May19 Shift VCO tuning range to avoid false locks. Reiland/Petencin
97Mar24 First data logged on miranda. Martin
96Sep-97Mar Move interferometer from MK, install at VLA. Petenicin et al.
Modified on Friday, 26-Sep-2008 12:09:05 MDT by Chris Carilli