SPAN

          REAL SPAN[2]

    SPAN indicates the limits of 2-D plot along the velocity axis,  while  RANGE
    indicates  the  3rd axis range that is displayed in the integrated spectrum.
    The spatial dimension (if any is displayed) is controlled by SIZE  and  CEN-
    TER.

    If  SPAN  is  0, it defaults to RANGE. If RANGE is zero, all planes/channels
    are displayed.