MPIComparePoint

Declaration

typedef struct MPIComparePoint{
	long                        position; 
	MPIComparePointDirection    direction;
	MPIComparePointAction       action;
	long                        width;
}MPIComparePoint;

 

Required Header: compare.h

Change History: 04.00.07

Description

MPIComparePoint specifies the information required to specify a single point for compare.

position Represents the position(or delta in case of delta point) to trigger the output action. .
direction Represents the direction of motion (positive or negative).
action Represents the action to perform when the position from feedback matches the compare value.
width Represents the output pulse width. Width maybe specified in either time (ns) or position counts.

Sample Code

This code fragment shows how to initialize a point before loading it into the controller:


		MPIComparePoint comparePoint;
		/*Generate an output pulse starting when position feedback >= 10000 
		 *and ending when postion feedback >= 12000*/
		comparePoint.position	= 10000;
		comparePoint.direction	= MPIComparePointDirectionPOSITIVE;
		comparePoint.action		= MPIComparePointActionPOSITION;
		comparePoint.width		= 2000;

		/*Generate an output pulse starting when position feedback < 10000 
		 *and ending after 2000 ns */
		comparePoint.position	= 1000;
		comparePoint.direction	= MPIComparePointDirectionNEGATIVE;
		comparePoint.action		= MPIComparePointActionTIMED;
		comparePoint.width		= 2000;

		/*Assert the output signal when position feedback >= 15000*/
		comparePoint.position	= 15000;
		comparePoint.direction	= MPIComparePointDirectionPOSITIVE;
		comparePoint.action		= MPIComparePointActionNEGATED;
		comparePoint.width		= 0;	/*Not applicable*/
		
		/*Negate output signal when position feedback < 20000 */
		comparePoint.position	= 20000;
		comparePoint.direction	= MPIComparePointDirectionNEGATIVE;
		comparePoint.action		= MPIComparePointActionASSERTED;
		comparePoint.width		= 0;	/*Not applicable*/	

		/*Compare hardware waits for position feedback >= 25000 (no output signal) */
		comparePoint.position	= 25000;
		comparePoint.direction	= MPIComparePointDirectionPOSITIVE;
		comparePoint.action		= MPIComparePointActionNOP;
		comparePoint.width		= 200;	/*Width for NOP is ignored*/

		/*Generate position delta in positive direction */
		comparePoint.position	= 500;
		comparePoint.direction	= MPIComparePointDirectionPOSITIVE;
		comparePoint.action		= MPIComparePointActionPOSITION;
		comparePoint.width		= 200;	

		/*Generate time delta in positive direction */
		comparePoint.position	= 500;
		comparePoint.direction	= MPIComparePointDirectionPOSITIVE;
		comparePoint.action		= MPIComparePointActionTIMED;
		comparePoint.width		= 200;

See Also

mpiCompareConfig