IMAQ Snap VI

NI-IMAQ VI

IMAQ Snap VI

Installed With: NI Vision Acquisition Software

Acquires a single image into Image out. A snap is appropriate for low-speed or single-capture applications where ease of programming is essential.

If necessary, this VI performs a system initialization using IMAQ Init before the acquisition. When you invoke a snap, the VI initializes the device and acquires the next incoming video frame to a buffer.

IMAQ Snap

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Channel specifies the device channel to acquire from. This parameter is valid only for NI PCI/PXI-1409 and NI PCI-1410 devices.

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Region of Interest specifies a rectangular portion of the image. Region of Interest is defined by an array of four elements [Left, Top, Right, Bottom]. You must set the width [Right-Left] to a multiple of eight. The [Right] and [Bottom] coordinates are exclusive. If Region of Interest is not connected or empty, the current region of interest is captured.

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IMAQ Session In identifies the device.

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Image In is a reference to an image that receives the captured pixel data.

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error in (no error) describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.

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status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.

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code code is the number identifying an error or warning. If status is TRUE, code is a non-zero error code. If status is FALSE, code can be zero or a warning code. Use the error handler VIs to look up the meaning of this code and to display the corresponding error message.

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source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.

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Step x is a horizontal sampling step or horizontal reduction factor. If Step x is set to 1, each column of the image is transferred. If Step x is not connected or is set to -1, the current value of the Horizontal Scaling property is used. Step x accepts only values of -1, 1, 2, 4, or 8.

Note  This parameter is deprecated and not available on all NI image acquisition devices. Horizontal scaling is not supported on the NI 1427, NI 1429, NI 1430 or NI 17xx smart cameras.
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Step y is a vertical sampling step or vertical reduction factor. If Step y is set to 1, each column of the image is transferred. If Step y is not connected or is set to -1, the current value of the Vertical Scaling property is used. Step x accepts only values of -1, 1, 2, 4, or 8.

Note  This parameter is deprecated and not available on all NI image acquisition devices. Vertical scaling is not supported on the NI 1427, NI 1429, NI 1430 or NI 17xx smart cameras.
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IMAQ Session Out has the same value as IMAQ Session In.

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Image Out is a reference to the image.

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error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out indicator on the front panel and select Explain Error from the shortcut menu for more information about the error.

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status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.

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code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.

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source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.