This invention provides a trigger for a vision system that can be set using a user interface that allows the straightforward variation of a plurality of exposed trigger parameters. Illustratively, the vision system includes a triggering mode in which the system keeps acquiring an image of a field of view with respect to objects in relative motion. The system runs user-configurable “trigger logic”. When the trigger logic succeeds/passes, the current image or a newly acquired image is then transmitted to the main inspection logic for processing. The trigger logic can be readily configured by a user operating an interface, which can also be used to configure the main inspection process, to trigger the vision system by tools such as presence-absence, edge finding, barcode finding, pattern matching, image thresholding, or any arbitrary combination of tools exposed by the vision system in the interface.