Setting the central wavelength

last update: June 9 1996 by ejb

1. Edit "instrpar" and give "tiltpos=7725" and "order=0"
2. Run "instrument" the echelle and prism will now move
   to the required position.
3. Sometimes the echelle (on CCD movement in dispersion direction)
   or the prism (on the CCD movements in the cross-dispersion direction)
   cannot be changes by small amounts in the tiltpos,,e.g. 1 angstrom.
   In this case go to a unix window and:
   * type "cd /usr/local/src/2dcoude"
   * type "source setup_2dcoude.csh"
   * type "2dcoude_test"
  0) Return
  1) Hardware Reset
  2) Hardware Abort
  3) Soft Stop
  4) Request Limit Switch Status
  5) Read Input Ports and Motion Status
  6) Read Motion Constants
  7) Set Motion Constants
  8) Compute prism encoder reading for a specified wavelength
  9) Compute wavelength for a specified prism encoder reading
 10) Compute echelle encoder reading for a specified wavelength
 11) Compute wavelength for a specified echelle encoder reading
 12) Read an encoder
 13) Move prism to a new central wavelength
 14) Move prism by an increment in wavelength in either direction
 15) Move echelle to a new central wavelength
 16) Move echelle by an increment in wavelength in either direction
 17) Send a known byte pattern to the stepper motor port
 18) Send a command manually to the stepper motor controller
 19) Toggle the status of the echelle/prism cradle brake

   this should give you a tool to change the tiltpos by small amounts.
4. If you are ready to observe:
   * in IRAF type "observe" and respectively "1" "object" and "200"
     to make an integration of 200 seconds of a star or sky spectrum.
     if you want to make a dark type "1" "dark" and "0"
     for a flat type "1" "flat" and "180".