imaqIOChangeDetectQuery

Format

rval = imaqIOChangeDetectQuery(IMAQIO_SESSION id, IMAQIOSignalType triggerType, unsigned long triggerNumber, unsigned long* changed);

Purpose

Queries the NI-IMAQ I/O device for information about whether the given trigger line has changed. For this function to behave properly, you must have previously configured the change detector for the same trigger line using imaqIOChangeDetectConfigure. After a change has been registered for a trigger line, this function will continually report that the trigger line has changed until you reset it by calling imaqIOChangeDetectReset.

Parameters

Name	Type	Direction
id	IMAQIO_SESSION	input
triggerType	IMAQIOSignalType	input
triggerNumber	unsigned long	input
changed	unsigned long*	output

Parameter Discussion

id is the ID of the NI-IMAQ I/O device that will be detecting trigger line changes.

triggerType is the type of trigger line to detect a change on.

triggerNumber is the trigger number to detect a change on.

detectMode is the change detection mode. This specifies what type of edge to be sensitive to.

changed is a pointer to a variable to receive the trigger changed information. If no change was detected, the variable will be set to 0. Otherwise, the variable will be set to 1.