Can someone explain a little bit about the Low-Level grab async.vi (Lv 8.5)

[lshi]

Is this build for the external triggering? What is the "BufferInterval" right under the "FrameDone" for? The example wires 2 for it. Would that make the "ActualBufferNumber" always located in the place of Buffer # 0? My understanding if not wrong is that the "Get Image" always waits for the current buffer to be finished and then takes this as the image.  So would it make any difference if I set "Number of Buffers" to 2 (since it has to be > 1) and "BufferInterval" to 1?

Thanks in advance,

Lei

[seVEMes]

In the NI-IMAQdx Function Reference Help there is information on this Low-Level Event.

The register frame done event "configures the NI-IMAQdx driver to execute a callback function when a frame done event occurs." The buffer interval specifies "the number of images to acquire before executing the callback function. Specify a buffer interval of 1 to receive a callback for every buffer."

Let me know if this does not answer your questions.