SET MODE

                  SET MODE Imode [/ANTENNA Iant]

         Specifies the observing mode Imode, which can take the values

    INTERferometer:  Select interferometric observing mode,  allowing  AUTO,
    CALIBRATE, GAIN, FOCUS, POINTING, SKYDIP and Cross correlation observing
    procedures.  The correlators are used for pointing and focusing in cross
    correlation  mode.   In addition an ONOFF procedure allows spectra to be
    taken with all antennas at the same time.

    OPTICAL:  This mode is used for  optical  pointing.   The  only  allowed
    commands  are  SOURCE  and  LOAD  in  this  mode.   The optical pointing
    constants and refraction model are used for tracking.

    CONFIGURE:   This  mode  is  used  to  specify  a  change  of   hardware
    configuration, such as new position of antennas, new IF connections, new
    pointing constants, etc...  The OBS\ language becomes inactive, and  the
    SET\  language is turned on.  Observations can be resumed only using the
    SET\OBSERVE command.

    TEST:  This mode is used  for  tests  of  the  correlators.   LO1  Walsh
    switching,  phase  and  delay  tracking  are  suppressed.   The spectral
    correlator  is  automatically  connected  to  the  noise  source.    The
    continuum  correlator must be manually connected to another noise source
    to  be  tested.   Antennas  are  unused  and  several  commands   become
    unavailable in this mode.