FOCUS

                  OBS\FOCUS [Length [Npos]] [/ANTENNA A1 ...  An]

         In  INTERferometric   mode,   starts   an   interferometric   focus
    measurement.   A1 ...  An is the list of antennas to focus (default: all
    antennas).  Three or more antennas must be connected,  or  one  must  be
    fixed.  Npos  is  the number of focus position to check (3 or 5, default
    3).

         Length is the focus displacement in millimeter (default 2.0  at  86
    GHz).  The command is forbidden in OPTICAL or TEST modes.