• To change gratings on IDS you must type the following command on lpss7:
      SYS> change_ids
• This pops up the INT IDS change window.  Click on  Access grating port  and answer 'yes' in the new window
  
• Go to the telescope and take your old and new grating boxes
• Open the grating box, open the three screws which fix the grating, and remove it
• Mount the new grating with the labels in the correct position (this depends on the camera, check the labels under the grating door) and fix the screws
• Close the grating door and come back to the telescope control room
• Click the CLOSE botton and change the appropiate information on the grating box, click on Save Changes and Exit
• Open the camera and the grating shutters: 

            SYS> gshut open            
            SYS> camshut open

• Select the requested central wavelenght by typing:
    SYS> cenwave 6000

• To change collimators on IDS you must type the following command on lpss7:
       SYS> change_ids
• Go to the telescope and take your old and new collimators boxes
• Open the collimator box and open the three screw which fix the collimator
• Take out the actual collimator in IDS
• Mount the new collimator. There is just one permitted position for collimator.
• Close the collimator door and come back to the telescope control room.
• Click the OK botton and change the appropiate information on the collimator box
• If necessary, open the camera shutter and the grating shutter:

  SYS> gshut open

  SYS> camshut open

• Mount a grating that gives well separated and well distributed lines on the CCD (e.g. R1200R)
• Select an appropiate central wavelength (e.g. cenwave 7300)
• Window the CCD so as to cover only the slit area. Recent window values are (20060613):
       SYS> window 1 "[730:1230,1:4200]"
  
• Take an arc to check counts and rotation
       SYS> complamps CuNe+CuAr
       SYS> arc 4 ``CuNe+CuAr''
• In IRAF, type ing to initialise the ING package
• Run ids_rotation to check the image rotation:
       ing> ids_rotation r??????[1]
• If necessary (rotation > 0.5 pixels), go into the dome and apply the recommended rotation offset
• To correct from tilts, select three isolated spectral lines in your arc. Those lines should have good SN, not saturated, and be located in the upper, middle, and lower part of the CCD (but not too close to the edge, otherwise one or the other of the Hartmann shutters might cover some of them)
• Put the collimator at the nominal position:
      SYS> collimator 225
• Take two exposures, one with the left hartmann shutter closed and one with the right Hartmann:

      SYS> hart 1 0 

      SYS> arc 8 ``Hartman L''

      SYS> hart 0 1

      SYS> arc 8 ``Hartman R''

• In the DRS, run the ids_tilt script:
       ing> ids_tilt r345678[1] r345679[1] 177 559 978
• Check that the computed pixels shifts are reasonable, otherwise the lines selection might have to be changed
• Apply the recommended turns for A,B, and C capstan or the focus offset, or if only focus should be corrected then change only the collimator value, by typing e.g.
       SYS> collimator 230                        (note that the recommended collimator value should be between 215 and 240)
• If all the pixels shifts are lower than 0.5 pixels, do not apply any capstan offset. Sometime there are errors in the capstan recommended values.
• Repeat the above procedure until pixel shifts are lower than 0.5 pix in the nine positions
• Do not forget to open both Hartmann shutters:
      SYS> hart 0 0
• Do not forget to update the web table with the micrometers positions for capstans A,B,C, and D (rotation).