WORKING ON IT: TROUBLESHOOTING AND TIPS

TCS

• When entering the coordinates manually, press POSITION ENTRY switch twice to send the coordinates to the TCS, this will help to avoid some errors in positioning.
• Do not forget to run INCL on Tycho, at beginning and end of night, to keep track of how the pointing is doing. The encoders values for both focal are on the board.
• To correct the encoders values at zenith,
  • ENCODERS in TCS window,
  • run INCL,
  • Z in TCS window.
  Note: For the INCL program, one count corresponds to 3.2 near zenith, +/- 1.8 degre from sensors vertical position.
• Do not forget there is a STOP SLEW switch on the right tcs console...
• EVIG. STP light on (top left, left TCS console), check emergency stop buttons are not locked.
• Check the RA arm whenever the telescope has hit something, if you need to move it back, somebody else should be holding the main reset button (inside structure).
• EMERGENCY STOP light on (two in the Dome), you have to hold on the main reset button, while the observer resets them.
• In case of COMPUTER FAILURE,
  • disk drives on,
  • reload the last version of the disks,
  • answer TCS window questions,
  • CHRONO-TIME for extra check,
  • disk drive off,
  • correct the pointing on a BS,
  • If you cannot find a BS, see Z procedure above.
  • No BS,
    • turn off all switches on right console, to avoid they come back at once when power back on,
    • turn off LSI-II (inside switch),
    • open left TCS panel and turn off the power switch (up),
    • reload the last version of the disks,
    • the TCS software will ask you to turn switches back on one by one.
  • If the astronomer wants you to enter the OFFSETS, enter (-)##.# (RA) (-)##.# (DEC) OFFSET in TCS window, exple, to offset 230N, enter 0.0 230.0 OFFSET, to go 10 further N, enter 0.0 240.0 OFFSET (absolute offsets). OV sets the offset velocity.

POINTING

• The SAO star is not in the field, another SAO nearby is not in the field neither, go back to zenith, try to find a bright star, the astronomer can take an exposure, or you can search with the guider probe on axis, the field is much smaller but you will see reflections from a very bright star. Make a Z procedure (ENCODERS, INCL, Z), then check on a BS and a nearby SAO.
• A consistant move in one direction, eg E-W, may be due to
  • resonance with the Telescope, change the integration time, the average or treshold,
  • windshake, try another direction,
  • the Telescope is out of balance, the DECLINATION PRE-LOAD might be off (right TCS console), or the RA weight is not set.
• The meters indicate excessive motor currents on RA or DEC, see out of balance condition above.
• If you have positionning or tracking problems, check the RA arm jack is still in position, the platform might have hit the telescope. Positionning errors might also occur when the observer and you have been sending commands simultaneously.
• The Telescope has lost pointing, and it cannot be restored by setting proper values to the encoders. The Telescope has to be moved back to the zenith by centering the bubbles, type ENCODERS in TCS window, center the bubbles using the paddle in the dome, with the audio on to ask slower or faster tracking rates to the observer (1 t0 50), then type Z in TCS window to set the zenith coordinates.
• You have reached a limit and lost the pointing, check the brakes are not enabled, move to the zenith, you might have to do it manually, then Z procedure (ENCODERS, INCL, Z).

DOME

• Type DOME in TCS window,
• check the dome control switch (left TCS console) is in Computer position,
• try to move the dome a little bit manually,
• try to go to the zenith,
• check the wind is not too strong, try in another direction,
• reload the TCS software
• follow the usual closing procedure, power down the control system (inside left TCS console) and LSI-11,
• if dome consistantly off, try fudgedome in xterm window.

TIC

• Make sure SM window is on.
• If TIC program behaving weirdly, exit and enter the program again.

AUTOGUIDER

• The guiding rate must be 0.5 arcsec/sec (automatic update).
• Choose the GS according to the offsets the astronomers plan to do.
• If the guider is having a hard time or crashed, they might have sent an A offset (Telescope only) instead of a G offset (Telescope + Probe), so offset the probe or offset back the Telescope.
• On ATLAS,
  • check focal ratio and rotator angle are properly set,
  • if running loose, try to click in another window,
  • go in and out the program if problems.
• On OTTO, the autoguider does not acquire the GS using Tip-Tilt and Enable buttons, the star goes out of the mirror corrections area, shut down all programs on Viper and log out. Log back in and start over. Try this more than once, if it fails, log out then power down the PI controller on the Telescope, then back on.

INSTRUMENT

• Round fuzziness in image, ice buildup or condensation on window.
• Shadow or edge of brightness on image, light reflecting on the guider probe.
• Edge or tunnel or spiral dark image, the shutter is not opening or closing fully, or not holding properly.
• Line or edge in image, the filter wheels is not in proper position, or pieces of tape have fallen off while moving it.
• Streaks or stars trails on image, check the tracking, make sure the Telescope has not hit something, or if the power on RA and DEC is off.
• With f/31, scattered background light, or ghosts, or reflections, check the baffle is on (send the Telescope to the South and look inside), it could also be any of the reasons above. If nothing is working, make sure you turned on the Tip-Tilt controller.
• Make sure you lock properly the rotator anytime you move the slit.
• The instrument is not communicating with the computer, turn on and off the switches for that particular instrument, if it does not work, turn on/off again, then on/off the computer (Wekiu,Halley?), if it still does not work, turn on/off the computer first, then the instrument.

SOFTWARE

• NEXT
  • Click on another window, then in Viper if running loose.
  • Quit the program and enter it back.
  • Shutdown with Power key on keyboard, Power key again to bring it back.
  • To power it down is usually a source of worst troubles.
• TYCHO or other Sun stations
  • Try to kill the appropriate process from Obs on Next.
  • Kill TO on top of processes.
  • Shutdown with /etc/shutdown -r now
  • Halt with /etc/shutdown -h now, then b to reboot.
  • Halt before power down (eg for a lightning procedure).
  • If you have rebooted several computers, Tycho has to be brought back up first.
  • If the guider does not communicate with Tycho, log out Next, then shutdown Tycho.
• TCS
  • TCS window locked, check for computer failure on right TCS console, try a START, if not enough, reload the last version.
  • Alt-A to get capital letters.
  • To manually check communications from Tycho to XY stage, type tip xystage, you should get a :, hit return, then enter TP to read XY position, ~. to end session.
  • To check on tcsd problems, enter ps -aux | grep tcsd. Old tcs daemon is /usr/loca/etc/tcsd, new tcs daemon is ~to/bin/tcsd.new

OPENING PROCEDURE / RIGHT TCS CONSOLE / LEFT TCS CONSOLE / CLOSING PROCEDURE / Back to 88inch Menu /

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