imaq1394GetAttributeCW

NI-IMAQ for IEEE 1394 Cameras Function

imaq1394GetAttributeCW

Format

imaq1394GetAttributeCW (sessionId As SESSION_ID, Attribute As Attribute, value) As IMG_ERR

Purpose

Gets an attribute for a camera.

Parameters

Parameter Type Description
sessionId SESSION_ID A valid Session ID, which you can obtain using imaq1394CameraOpen2.
attribute Attribute The Attribute whose value you want to obtain. Refer to Attributes for a list of attributes.
value VARIANT (passed by reference) The value of the specified attributes when the function returns.

Parameter Discussion

attribute specifies the attribute whose value you want to obtain. In LabWindows/CVI, when you click the control or press <Enter>, <spacebar>, or <Ctrl-down arrow>, a dialog box opens containing a hierarchical list of the available attributes. Attributes whose values cannot be obtained are dimmed. You can access function help text for each attribute by double-clicking an attribute or by selecting the attribute and pressing <Enter>.

If the attribute shown in this ring control has named constants as valid values, you can bring up a list of them by moving to the Attribute Value control and pressing <ENTER>. If there is a value shown in the bottom half of the Attribute Value control, the corresponding constant is marked in the displayed list.

If the specified attribute is a camera attribute, the driver may return one of the following values:

  • IMG1394_AUTOMODE: Allows the camera to always control the selected camera attribute.
  • IMG1394_ONEPUSHMODE: Allows the camera to control the selected camera attribute once, and then return to the manual control state with adjusted values.
  • IMG1394_OFFMODE: Disables the selected camera attribute.
  • IMG1394_ABSOLUTEMODE: Sets the selected camera attribute to use 32-bit floating-point numbers that map to real-world units. In this mode, the driver refers to the absolute camera attribute for the control value.
  • IMG1394_IGNOREMODE: Prevents the driver from accessing the selected camera attribute.

Return Value

On success, this function returns IMG1394_ERR_GOOD. On failure, this function returns an error code. You can obtain a more detailed error message with imaq1394ShowErrorCW.