Common VI Parameters

NI-IMAQdx

Common VI Parameters

Image Buffer

Many acquisition VIs require an image buffer to receive the captured image. You can create this image buffer using the IMAQ Create VI. Refer to Buffer Management for more information about using buffers. Image In receives the image buffer. Image Out returns the captured image.

Session In and Session Out

Session In is a unique identifier that specifies which interface file to use for the acquisition. An NI-IMAQdx Session is produced by the IMAQdx Open Camera VI and used as an input to all other NI-IMAQdx VIs. The NI-IMAQdx VIs also use Session Out, which is identical to Session In, to simplify dataflow programming. Session Out is similar to the duplicate file sessions provided by the file I/O VIs. The high-level acquisition VIs—IMAQdx Snap, IMAQdx Configure Grab, and IMAQdx Sequence—require you to wire Session In only in the following instances.

  • If you are using an interface other than the default cam0
  • If you are using multiple cameras
  • If you need to set NI-IMAQdx properties before the acquisition

To get and set properties of the acquisition and camera, wire the Session In to the LabVIEW Property Node.