Example

Suppose there is a program DISP that draws an image on an image display device. It has three parameters:

IMAGE

the dataset containing the image to be drawn,

DISPLAY

the name of the image display device, and

LIMITS

an integer array of limiting values.

The Interface File might be:

INTERFACE DISP
   .
   PARAMETER IMAGE
         .
      TYPE IMAGE
         .
   ENDPARAMETER
   PARAMETER DISPLAY
         .
      TYPE IMAGEDISPLAY
         .
   ENDPARAMETER
   PARAMETER LIMITS
         .
      TYPE _INTEGER
         .
   ENDPARAMETER
      .
ENDINTERFACE

If the user specified a value of [1.2,511.8,255.6,512.1] for the LIMITS array, i.e. a _REAL array where type _INTEGER is specified for the parameter, the system knows that this is a valid conversion and can perform it for the user (i.e. [1,511,255,512] is stored).

Similarly, the program could try to obtain a _REAL array from the parameter storage (by calling PAR_GET1R). In that case, the array would be converted back to _REAL although the numbers supplied by the user would have been truncated (i.e. [1.0,511.0,255.0,512.0] would be supplied to the program).