*+
*  Name:
*     IMG_CONST

*  Purpose:
*     Define private (internal) constants for the IMG_ system.

*  Type of Module:
*     Fortran include file.

*  Language:
*     Starlink Fortran 77

*  Description:
*     This file contains PARAMETER definitions of constants which are
*     used internally by the IMG_ system.

*  Authors:
*     RFWS: R.F. Warren-Smith (STARLINK, RAL)
*     PDRAPER: P.W. Draper (STARLINK - Durham University)
*     {enter_new_authors_here}

*  History:
*     18-FEB-1992 (RFWS):
*        Original version.
*     19-JUL-1994 (PDRAPER):
*        Added IMG__MXEXT to define number of extensions an NDF
*        can have open.
*     28-NOV-1994 (PDRAPER):
*        Added size of NDF name.
*     {enter_further_changes_here}

*  Bugs:
*     {note_any_bugs_here}

*-

*  Global Constants:
      INTEGER IMG__MXPAR         ! Max. number of active parameters
      PARAMETER ( IMG__MXPAR = 256 )

      INTEGER IMG__NOPTR         ! Null mapped data pointer value
      PARAMETER ( IMG__NOPTR = 0 )

      INTEGER IMG__SZPAR         ! Length of a parameter name
      PARAMETER ( IMG__SZPAR = 15 )

      INTEGER IMG__MXEXT         ! Maximum number of "open" extensions
      PARAMETER ( IMG__MXEXT = 10 )

      INTEGER IMG__NEXTS         ! Product of IMG__MXPAR and IMG__MXEXT
      PARAMETER ( IMG__NEXTS = 2560 )

      INTEGER IMG__SZNAM         ! Size of NDF name string
      PARAMETER ( IMG__SZNAM = 200 )

*.
* $Id: img_const,v 1.1 1998/06/03 13:15:21 pdraper Exp $
