It is often necessary to refer to an ADAM program parameter in a message. There are two kinds of reference required:
Parameter references can be included in the text of a message by prefixing their names with the appropriate escape character. To include the keyword associated with a parameter, its name is prefixed with the percent escape character, ``%'', e.g.
CALL MSG_OUT( 'ET_RANGE', '%ET parameter is ignored.', STATUS )
Here, the parameter `ET' might be associated in the interface file with the keyword ``EXPOSURE_TIME'', e.g.
parameter ET type '_INTEGER' keyword 'EXPOSURE_TIME' prompt 'Exposure time required' endparameter
In this case, the resultant output would be
EXPOSURE_TIME parameter is ignored.
To include the name of an object, device or file associated with a parameter, the parameter name is prefixed with the dollar escape character, ``$'', e.g.
CALL MSG_OUT( 'DS_CREATE', 'Creating $DATASET.', STATUS )
If the parameter `DATASET' is associated with the object called ``SWP1234'' then this would produce the output
MERS (MSG and ERR) Message and Error Reporting Systems