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AF2 Change document

Please report any errors or other suggestions to Rene J. Pit

Instrument change date  
Instrument change leader  
Other teammembers  

Tick below when all sections are completed

Section 1: preparation Section 4: cables and fibres
Section 7: astronomy checks
Section 2: remove secondary Section 5: setup in control room

Section 3: fit AF2 Section 6: duty checks

 

Section 1 : Preparation (During week before)

 
Check that GHRIL is prepared

  1. Internal inspection of WYFFOS. Clean inside and ensure fibre bundle is connected to the slit.
  2. Check engineering schedule.  Set-up WYFFOS for correct mode (reflection or echelle).
  3. Ask the support astronomer which grating is being used.
  4. Check WYFFOS CCD is prepared and cold, cycle if required.
  5. Ensure clear access is available for WYFFOS grating.
  6. Check WYFFOS is operational and all maintenance etc is complete.
  7. Check WYFFOS Calibration Unit is operational and all maintenance etc is complete.
  8. The following is normally left connected, but needs to be checked.
  9. Set up AF2 Power PC, Interface rack and  power amplifier rack in GHRIL control room.
  10. Connect the AF2 cable loom from prime to the Interface  crate and AF2 servo amp crate.
  11. Connect the AF2 servo amp crate to the Interface crate.
  12. Connect Gripper TV BNC   to Linux Power PC  connector on video in cable.
  13. Connect the video out BNC to Gripper monitor BNC that goes to  No.82 on the patch panel
Check that the Prime Focus Unit is prepared.
  1. Check the Prime Focus Unit is in its handling trolley and ensure that the prime focus instrument platform PFIP has been removed
  2. Ensure the lifting frame is correctly balanced for lifting the Prime Focus unit.
Check AF2
  1. Remove AF2 Robot from its handling trolley and put it in its lifting frame.
  2. Prepare AF2 Robot and the small fibre module for lifting up to the dome area in the morning.
  3. If required AF2 can be tested with the telescope at AP3, with its cables and compressed air connected to the top ring. Instead of moving all the equipment down to the focal test station.
  4. In that case ask the mechanical section to crane up the AF2 robot and fibre module some days before the change.
  5. Its recommended to do the initial robot test without the fibre module in place, as the theta mechanism gets stuck sometimes, when the instrument has been stored along time. If the robot has difficulties moving in Z, and for checking the gripper rotator centre reduce the air pressure to ~3 Bar
  6. After the test the cables can be coiled-up, and left connected to the top ring connector plate until the change. Make sure the cables don't disturb the movement of the flip-ring.
Check Ancillary equipment.
  1. Check you have a working TV camera AG2 head and controller.
  2. Check you have a working autoguider AG1 or AG5 and controller.
  3. With the telescope at zenith park check flip ring operation.
  4. Locate swans neck and CCD controller racks.
  5. Check that all cables are accounted for.
Check lifting equipment
  1. Two one tonne strops and shackles required.
  2. Looking down from AP3. Place the following trolleys on the ground floor to the right of the telescope. Secondary Lifting Trolley and frame, Prime Focus Unit, AF2 robot in its handling trolley.
Check control room is prepared
  1. Connect AF2 video monitor to GHRIL patch panel: video=82.

 

Section 2 : Removing Secondary Mirror  (instrument change day)  

 

Telescope Preparation:

  1. Check Logbook for any restrictions or on going work.
  2. Make entry in the logbook and apply any necessary restrictions or permit locks.
  3. Turn on oil systems and Altitude and Azimuth power amps.
  4. Check that the speaker located on the engineering console is connected.
  5. Bring telesope down to AP1 and check that the flip ring is turned on.
  6. Take the white dust cover off
  7. Send telescope back to zenith park.
  8. At zenith park flip top ring to prime focus position.
  9. Bring telescope down to AP3.
  10. Put in both AP3 telescope ties.
This concludes the telescope preparation complete instrument change can start.  IMPORTANT Do not turn of oil system.

Secondary Mirror Removal:

  1. Remove Secondary Baffle
  2. Un-cable secondary Mirror power supply cable and the 3 LVDT's.
  3. Back off and secure with lock nut, the two top bolts that position the secondary mirror in X,Y translation. Never loosen the bottom two bolts, as you will loose alignment.
  4. Fix lifting frame remove bolts and lift to the ground floor.

 

Section 3 : Installing AF2  

  IMPORTANT: Great care must be taken when placing the PFU in the telescope. This is because the crane beam and telescope axes are not orthogonal.

Fitting Prime Focus Unit.(PFU)

  1. Check that the lifting frame centre of gravity is correct for the PFU.
  2. Lift Unit from ground floor.
  3. Secure PFU to telescope with six bolts.
  4. Lower PFU lift frame to ground floor.
  5. Connect cables from telescope to PFU.
  6. Turn on PFTT power amp in control room and ensure you can rotate the PFU locally. Make sure cables and especially the fibres are not being stressed to much!
Fitting AF2 Robot
  1. Lift AF2 robot from the ground floor to AP3.
  2. Offer AF2 up to PFU unit. Move PFTT until the dowels align.
  3. Secure AF2 to the PFU. Be very carefull to not touch any of the limit switches, or the gripper camera, during this operation!
  4. Are all bolts tight?
  5. Lower lifting frame to the ground floor.
  6. Fit robot cables between AF2 and top ring patch panel.
  7. Connect compressed air supply to robot.
  8. Cover small or large fibre module sensor (depending on which fibre module is being fitted.) with a piece of metal and some sticky tape.
  9. Ensure all staff are clear from the robot, as it can move without warning.
Test that the robot works with a ssh (secure shell) session to the af2pc1
  1. First power on af2 pc, if not already running. (to ensure that the outputs from the motion controller card are in the correct state before powering on the rest of the electronics)
  2. Power on af2 interface crate
  3. Power on af2 servo amplifier crate
  4. Power on af2 power at prime by connecting mains cable
  5. The following is best done with laptop PC in the dome near the AP3, running Linux.
  6. If you need fixed network connection, there is a network switch in the dome PLC cabinet with a long UTP cable coiled up.
  7. Open a terminal and type: xhost +
  8. Then: ssh -X af2pc1.ing.iac.es -l af2
  9. username: af2
  10. password: **********
  11. Bring up the AF2 mimic by typing: AF2EngineeringMimic &
  12. af2 wake
  13. If AF2 wakes, then you will hear the gripper jaws actuate 3 times and will then move to the centre on the field.
  14. af2 sleep
  15. Close ssh session
  16. Remove the metal from the fibre module sensor.

 

Section 4 : Installing fibre module and cabling up:  
Fitting Fibre Module
  1. Two people lift the fibre module out of its box.
  2. Lift the fibre module on to the AF2 robot.
  3. Fit the spacers between the robot and the fibre module.
  4. Secure the fibre module with four cap head bolts and self-aligning washers.

Fit Ancillary items at top end

  1. Fit the swans neck.
  2. Fit A&G controller support frame and install SDSU controller.
  3. Install  TV camera system with AG2. Make sure the camera sits against the two reference faces. Optimum focus is at 5.42 mm on the micrometer. Make sure you use a safety harness, for cable connections and fibre routing to GHRIL!
Cable-UP Top end.
  1. Prime Focus Unit to AF2 Robot, AG1 or AG5 autoguiding, AG2 TV-acquisition.
  2. Cable up Autoguider.  Fibre connects to prime 1.
  3. Connections to the AG2 TV and interface
Connect up Science and Guide TV fibres.
  1. Clear area and ensure only change staff are present.
  2. Lay out all the fibres on the floor.
  3. Take the grey reels off the fibre module and store in cupboard
  4. Run the red science fibres from AF2 up to the topring
  5. Run the grey guide fibre to the  AG2 TV.
  6. Great care must be take when handling the fibres.
  7. Using cable ties secure all the fibres  at the end of the swan's neck. Ensure the cable ties are on the metal part not on the grey mesh.
  8. Very important. Move rotator locally to +/- limits. Check fibres twist OK. When A&G is at the top the rotator PA should be 90 degrees. 
Balance Telescope.
  1. Drive weights to the bottom.
  2. Paper calculation on moments removed and added.
  3. Release telescope ties when you are sure telescope is near to balance and slightly bottom end heavy.
  4. Check top to bottom
  5. Check across cube
  6. Check top to bottom

Section 5 : Setup in the Control Room:

  1. Restart the TCS, to make sure that the prime rotator incremental encoder is zeroset to the absolute encoder.
  2. Then configure the TCS for Prime, by typing: STATION PRIME, INSTRUMENT AUTOFIB, AGSELECT AF2_TV
  3. Change the DEWARS configuration web page to the following setup:
  4. Restart the observing system.
  5. Update the magnet board.
        

Section 6 : AF2/WYFFOS Checks  

        

The following commands that  are to be typed at the ICL command line, are given after the ICL prompt.

Testing AUTOFIB

  1. Waking the robot.
  2. Turn on the WYFFOS back-illumination.
  3. View a science fibre.
  4. View a guide fibre.
  5. Load the small fibre module.
  6. Turn off the backillumination
  7. Park the AF2 Robot
Testing the AG heads used for acquisition and guiding
  1. Turn off all dome lights
  2. Turn a Wyffos calibration lamps on.
  3. Take an 1 sec exposure with AG1 (autoguider)

            You should see the ten fiducial bundles now

  1. To test AG2 we need some light on the mobile probe. This probe is the small circle on the grey square that represents the gripper body (on AF2 mimic). Now make sure the mobile probe is in the field
  2. Take a 1 second exposure with AG2.

            The mobile probe should be illuminated now

  1. Sleep the robot

 

Testing WYFFOS

This is not a detailed check but proves communications. Moving other things like the grating can disturb the observers set-up.

  1. Make sure the Nitrogen flush for the CCD window is switched on (especially in winter with humid conditions) Open Epics engineering consul and switch LN2 flow on.
  2. Switch neon lamp on 
  3. Take an exposure with wyffos on taurus 
  4. Switch calibration lamps off
  5. Take a bias frame with wyffos on taurus
Testing the ADC.
  1. Use the wyffos mimic to display corrector element positions. Another way of doing this test, is using the Instrument Control Console, clicking the corresponding buttons, or ensuring both elements are move while moving the telescope in Elevation.
Section 7: Final Astronomy Checks  

Astronomy Checks (day time)

  1. AF2 field set-up from Taurus
  2. CCD focus.
  3. Check that WYFFOS angle offset is 6200 (wchange).
  4. Datum the two filter slides and lamp slide on the Calibration Lamp Mimic.
  5. Set calibration lamp timeout to 1800 seconds on the Calibration Lamp Mimic.
Astronomy Checks (night time)
  1. Check offsets on mobile and fixed probe. (see Autofib technical note 2. Section 6)


The instrument change and checks are now complete.  The telescope and instrument are ready for the telescope operator and observer.

Make sure all tickboxes are marked. Put this copy in the daily operations logbook.

 

Last updated 17nd Sep 2014 by RJP

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