National Instruments Image Acqusition Software NI-IMAQdx Manual De Usuario

© National Instruments Corporation

The Vision and Motion»NI-IMAQdx»NI-IMAQdx Low Level palette 
contains VIs for more advanced applications.

Refer to the NI-IMAQdx VI Reference Help for more information about 
using these VIs.

The following sections describe commonly used VIs and important 
parameters common to many VIs.

IMAQdx Session is a unique identifier that specifies which interface file to 
use for the acquisition. The 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 use IMAQdx Session Out, which is identical to IMAQdx 
Session, to simplify dataflow programming. IMAQdx 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 IMAQdx 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 IMAQdx properties before the acquisition

To get and set properties of the acquisition and camera, wire the IMAQdx 
Session to the LabVIEW property node. 

Many acquisition VIs require an image buffer to receive the captured 
image. You can create this image buffer with IMAQ Create. Refer to the 

 section of this chapter for more information about 

using buffers. Image In receives the image buffer. Image Out returns the 
captured image.