| date yymmdd |
td | description |
| 080623 |
12 |
load cell 2 replaced with spare
that had come back from being calibrated. |
| 080619 |
4 |
transmission
replaced. loadcell
recalibrated. |
| 080616 |
12 |
Found that load cell amplifier
was causing trouble with 5 volts supply. After disconnecting amplifier
the analog inputs read ok and the encoder stopped jumping. |
| 080608 |
12 |
encoder card on td 12 blown out
by lightning. |
| 080529 |
4 |
replaced
jack on tiedown 4. |
| 080407 |
8 |
td 8 stopped moving at
19.57. commanded velocity remained 0. |
| 080407 |
12,4,8 |
the torque readback
has occasional level shifts of up to 55 a/d counts. |
| 080312 |
12,4,8 |
recalibrated all 3 load cells.
td 12 now has hectors amp adjustement board (it was the last to not
have it). |
| 080228 |
12 |
replaced
transmission. Had a
loud knocking noise ... |
| 071011 |
- |
after 2nd set of az swings
updated the reference position to be: 15.0718,15.3196,15.0926 |
| 071010 |
- |
updated the tiedown reference
position. After azswing updated the reference position to be 15.1140,15.2028,15.1670 |
| 071209 |
4,8 |
moved the nuts on td4 down .5
inches, td8 nut up 3.25 inches to equalize the tiedown extensions. |
| 071004 |
12 |
motor faults. replaced motor. |
| 070328 | 4,8 | New amplifiers with hector's calibration boards installed on ldcells. Recalibrated ld cells. |
| 070206 | 4 | ldcells recalibrated |
| 061114 | 12 | ldcell 1 replaced. all load cells recalibrated |
| 061111 | 12 | ldcell 1 has bad resistance on 1 of the legs of the wheatstone bridge. ldcell2 is driving both inputs now. |
| 061108 | 12 | recalibrated both load cells. load cell 1 had water in the cover at the load cell. |
| 061101 | 4,8 | recalibrated load cells. |
| 061028 | 12 | replaced ldcell2 amplifier that was blown out on 061014. |
| 061014 | 8 12 |
lightning strike blew out td8. Had to change little star,
some of the
i/o boards, and some of the analog signal conditioning boards. td12 blew out ldcell2 amplifier. This is one of the new amplifiers. |
| 060908 | 12 | new online ups installed in td 12. |
| 060831 | 12 | forgot to swap the pots when the amps were swapped yesterday. corrected at 9:00 am |
| 060830 | 12 | load cell cable before the amplifiers back to normal order. ldc1-> output ldc1 now. |
| 060824 | 12 | load cell cables at load cell put back to normal order load Cell cable before amplifiers switched. ( in the morning). |
| 060823 | 12 | switched the load cell cables as they leave the load cells. |
| 060822 | 12 | cleaned the load cell cables where they connect to the load cells. They were pretty dirty (full of corrosion) |
| 060814 | 12 | swapped td12 ldcells back to normal position. They had been crossed at the analog input since 060719. Soldcell1 is again ldcell 1. Found the jumping problem was the db25 connector at box. Cleaning this fixed it. This td has no filters. |
| 060812 | 12 | td12 encoder reading failed around noon after a power dip.
The encoder
always read 9 inches and did not report an error. When requested to
move
to a higher or lower position (than 9 ") the tiedown would move until
it
hit the limit switch (since it was looking at the encoder to see when
it
got there). I manually moved td 12 to 12" using the tape measure.
I moved the other two tiedowns to the correct position when td 12 is at
12". This position is close to where the tiedowns were the previous
nite. I checked the voltage on the encoder board and it was ok (5 volts). On 060814 the problem had fixed itself. |
| 060719 | 12 | swapped td load cell inputs to a/d signal conditioning board to see if problem with ldcell 1 jumps to load cell 2. |
| 060628 | 12 | td 12 ldcell 1 started to fail on 28jun06. jumped to 40 kips and then back. Remained bad thru at least 17jul06 (date of this entry). |
| 060612 | 8 12,4,8 |
td 8 ldcell #1 amp changed. load cells recalibrated. td 12 ld cell 2 amplifier switched to new amplifier |
| 060526 | 12 | analog output values wrong (velocity feedback not eq to
requested).
Replaced analog output signal conditioning brd. The same problem
occurred
for a short thime on 21may06. The zero vel offset for the dacs jumped back up to 2016. There is something funny going on when we replace the analog output board for td12. The offset either sits around 2020 or 2000. Are we mixing the old and new boards when we replace them ??? see /home/phil/vw/datatk/pnt/ttt/tie/tieParms.log (at the bottom) for the history of the offsets. |
| 060426 | 12 | analog output board fails. replaced. |
| 060420 | 12 | digital i/o output was causing the master contactor to not close reliably (more info) |
| 060306 | 12 | encoder replaced. Also noted that the cable that encoder plugged into may have been dirty . cleaned with water displacer. |
| 060303 | 12 | replaced encoder interface board. |
| 060302 | 12 | td12 releases because of bad enc reading. |
| 051027 | all | installed db25 connector filters for load cell inputs and pcu . |
| 051026 | td12 | replaced analog output board and analog output signal condioning board. |
| 051014 | td4 | replaced amplifier. It went bad about a week ago. Recalibrated amp1 , amp2 of td4 |
| 050916 | td8 | the analog inputs from td 8 had trouble during the morning of 16sep05. The plots show all of the analog inputs vs time for the morning of 16sep05 (.ps) (.pdf) (black td12,red td4,green td8). The first 6 (+24volts, -24volts, brake24volts, ldcell1, ldcell2, and encoder 5 volts all jumped together. At 2:50 they jumped to the maxium value for a few minutes. From 3:30 to 4:00 and again at 6:10 they where at the maximum value. The velocity feedback and master amp speed monitor did not have this problem (the short spikes they have is rfi in the cabinet). The master amp current looks like it jumped up at 2:50 but not at the later times. Need to find out what these inputs have in common. |
| 050914 | td4 | Load cells out of calibration (again). ldcell1 amp had dc offset of 1.5 volts. Both load cells had small oscillations in the output (with no input load). Replaced both load cell amplifiers. |
| 050904 | td12 | db25 filter for pcu cable shorted out 24 volt supply. removed filter. |
| 050902 | td8 | both ldcell amplifiers 8-1, 8-2 had their excitation voltage
at 0.
replaced both load cell amplifiers then recalibrated. This had happened
a while back (probably on 25aug05. removed the db25 filter for loadcell 8-1. it was bad (need to send away for more filters). |
| 050902 | td4 | both load cell amplifiers have excitation voltage of 0. need to be fixed.. |
| 050825 | td8 | lightning.. replaced little star |
| 050825 | td12 | lightning .. replaced encoder interface board, signal conditioning for dac, analog input fuse for input 3? |
| 050728 | td12 | trouble with td 12. replaced little star. releasing. |
| 050625 | td12 | lightning trouble. See writeup. Ended up replacing little start, amp. |
| 050317 | td12 | replaced jack td 12. looked at prelim encoder position. moved by about .2 inches. |
| 050317 | td12 | replaced encoder board on td12. The encoder value had jumped from 13 to 24 inches at around 9am. |
| 050225 | td4 | td 4 jack breaks. looks like bad ball bearing. replaced jack 28feb05. reset limit switches, encoder. |
| 050131 | td12 | changed filter ldcell1,2. then the values were fine. Must have been water in the filter. |
| 050126 | td12 | td12 ldcell 2 value value jumped to a lower reading. this means that both load cells are reading low. |
| 050124 | ts12 | td12 ldcel 1 dropped about 10kips in 45 minutes. |
| 050117 | td4 | replaced filter on ldc1 cable.
it was
bad.. recalibrated all ldcells for the 3 tiedowns |
| 041116 | td4 | still trouble with td 4. occasionally when command from stop,
td 4
would 1.release the brakes 2. wait a few seconds 3. go max speed.. this caused and overspeed fault . replaced amplifier. Still had trouble. replaced a number of little stars, had trouble with parameters. Loaded ok but when we cycled power on LS, they went back to the original values. CB2,3 tripped again. Had to disable the fan on the box. Then it worked ok. Tried another little star and this time it worked. Left the box off till we could get the box fan working. |
| 041112 | td4 | jack released. kolmorgan power supply failed...replaced
15nov04. It
had a short. also changed the dac board and signal conditioning. |
| 040510 | td4 | loud noise from the jack. replaced the jack. This required dismantling the limit switches, encoder and then replaced after new jack installed. reference may have moved some. (our tape measurement were not longer valid since new jack). |
| 040317 | td8 | safety relay problem was water in liftoff switches. Only had 15 volts rather then 24. Cleaned the switch and it started working. |
| 040317 | td8 | db25 feed thru filter for pc. Replaced it and the pcu started working. |
| 040315 | pcu | pcu was not working . brought it up to the lab to check it out. (problem was feed thru filter td8) |
| 040315 | 8 | safety relay was not closing with result pulse. after cycling it manually a few times it started to work. Switched pcu relay with safety relay. problem was feed water in switch. ( see 040317) |
| 040315 | 4 | encoder jumping to 24". started 4th march, 12 march shut off. 15mar replaced encoder intf board. |
| 030930 | mod4 | changed little star td4 (battery was low). updated parameters in little star. |
| 030806 | mod 8 |
recalibrated loadcells on td 8 |
| 030806 | mod 4 |
rotated mounting bracket for limit switches to face away from the box. Old tape measurements no longer valid for td4. |
| 030730 | mod 8 |
final lower limit td 8 reset to be at encoder position 1.19". Ran the jack all the way to 0" encoder value and still did not hit end of jack (although it is probably pretty close). |
| 030728 | Note | The limit switches were changed to a newer type that did not leak (i'm not sure what date). It looks like they were mounted in the same position as the old switches even though the mechanical layout is different. The jack positions for where the limits triggered are now different. For td8, the jack runs all the way to the end of the jack and the limit switch has still not tripped. This is what caused the limits to not trip on 030728. All of the limit switches need to be repositioned so they are at the correct jack positions. |
| 030728 | Fail | lightning afternoon. |
| 8 | blew out dac. Td went all the way up. Final limit switch did
not trip. Replaced dac. Final limit switch has moved by more than 1 inch. Probably not the encoder since we actually ran into the end of the jack without hitting the limit. |
|
| 4 | Encoder board blown. Replaced board. Encoder before problem was 13.301. After it was 12.6?? Someone must have moved the td while board was bad. Since abs encoder was ok, position is probably ok | |
| 031111 | Fail 4 |
td4 drive disabled itself even though program thought it was
still
running. Luis found that the voltage regulator for the dac was shorted. Replaced dac. |
| 021003 | mod all |
5 volt supply for dacs is now coming from a separate power supply. It used to come from the dc to dc converter on the encoder board. Change made to t12. Need to also update the others. Need to move the 5 volt encoder voltage monitoring line from the dac to the a/d. |
| 021002 | Fail | lightning |
| 12 | blew out encoder interface. replaced. The kips were reading 81,82 until the encoder board was replaced. The lcd display on 12 was also acting up. | |
| 8 | blew out encoder interface board. replaced. Recalibrated td8 load cells. |
|
| 020923
|
fail 8 |
Axis fault always on. tiedown was oscillating. This can be
from encoder
init error or master contactor did not close after 20 cycles. This
encoder
interface board had been installed 10sep02. Replacing the encoder
interface
board fixed the problem. Updated the zero velocity offsets for td12 and td8. |
| 020910 | fail | lightning struck platform. |
| 12 | signal conditioning bad. Dac may also have been blown. Swapping encoder interface board screwed up dac or signal conditioning again.. This was an old encoder interface board. roc 424. | |
| 8 | encoder bad. Dac or signal conditioning also bad. | |
| 020815 | fail | power dip or lightning?? |
| 12 | dac output reading -2048 counts. cycling power fixed it. | |
| 4 | dac signal conditioning board blew. Outputting -24 volts. | |
| 8 | encoder reading 24 inches. encoder interface replaced with new encoder board/pal (425q pals. | |
| 020424
|
fail 8
|
power dip td8 not responding. +24 pwr supply has 3.5 volts. Removing little star fixed it so little start was shorting out pwr supply. Put in new little star, didn't work. Put in 2nd little start. Worked but had to update parameters. After updating parameters, would only move up , not down. Maxpos was 0 so i set it to 24000. Next day rebooted and it worked ok. Looks like for some parameters you need a reboot to take affect. |
| 011203 | fail8 | lightning . td 8 dead. Short in +24 volt power supply. |
| 011101 | fail8 | little start digital input lspin09 bad. opto-isolator on signal conditioning board shot. This caused the master contactor to always read closed, even when it was open. |
| 011101 | all | Tiedowns back on the air. They'd been off since 23sep01 |
| 011101
|
fail 8
|
amplifier for td8 amp had missing connections on a capacitor, resistor, and a blown capacitor. Replaced amp with repaired amp from kolmorgan. This amp had speed offset for the azimuth (it was an az motor). On td this caused and over speed. The dac output was 8 volts and the speed output (of amp) was over 11 volts. Tried adjusting a pot to bring the speed voltage to 0 but it looks like it screwed up the gain. Installed another amp and it worked ok. |
| 011031
|
fail8
|
load cell td8 amp1 jumped 1.2 volts in dc offset. (ldcell:#90407). Switched cables at output of load cells and still had the problem. Removed db25 connector at case and it worked ok. Replaced connector (these connectors have built in filters). Measured the resistance for the wheatstone bridge in td8,4 load cells. records in manual so you can easily check if the db25 connector is blown (it changes the resistance). |
| 011030 | mod | Td 8,td4 now have roq424/425 encoders. They work fine. Td 12
has old
roq424 encoder. it jumps in the 3rd hex digit from the right. Td8 A/D card jumper was not cut. did it today. |
| 011029 | mod | Replaced ldcell amp td8 #1. Recalibrated (but the a/d resistor had not been cut. |
| 010923 | fail | lightning. tiedowns remain down until 01nov01 |
| 12
|
encoder moving in wrong direction. Changed encoder, started
to move
and then little start died. changed little start. Luis had measured the
position at 14.7 inches. So moved td to luis's tape measurement and
then
set the encoder to 14.7 inches. Then went to the limits and got: expected measured 1.43 1.8473 .4 inches off 22.29 22.28 .01 inches off |
|
| 4 | encoder reads 24 inches. resetting td 4 seemed to fix it , but moving 4 then made a terrible noise. Dac is shot, red light is off. Replaced dac and switched to single ended mode on signal conditioning board (no jumper and 10k resistor). | |
| 8 | encoder reads 24 inches. cycling power it then reads 0
inches. Lifted bus cable to dac,di1,di2 and a/d started working. looks like dac is screwing up bus. Replaced dac, signal conditioning. still troubles. looks like encoder board is messing up the bus (need to build some more encoder boards for the new encoders). |