User`s guide

6 Acquiring Image Data

6-14

To execute another manual trigger, you must first restart the video input object.

Note that this deletes the frames acquired by the first trigger. To execute multiple

manual triggers, specify a value for the TriggerRepeat property. See “Specifying

Multiple Triggers” on page 6-32 for more information.

Clean up — Always remove image acquisition objects from memory, and the

variables that reference them, when you no longer need them.

delete(vid)

clear vid

Using a Hardware Trigger

To use a hardware trigger, create a video input object and set the value of the

TriggerType property to 'hardware'. You must also specify the source of the

hardware trigger and the condition type. The hardware monitors the source you specify

for the condition you specify. The following figure illustrates a hardware trigger. For

hardware triggers, the video stream does not start until the trigger occurs.

Note Trigger sources and the conditions that control hardware triggers are device

specific. Use the triggerinfo function to determine whether your image acquisition

device supports hardware triggers and, if it does, which conditions you can configure.

Refer to the documentation that came with your device for more detailed information

about its hardware triggering capabilities.