National Instruments Image Acquisition Software User Manual

Also see for NI-IMAQ: User manual

Contents

National Instruments Image Acquisition Software User Manual Manual pdf 25 page image

Chapter 3 Programming with NI-IMAQ©National Instruments Corporation3-5NI-IMAQ User Manualattribute value is a numeric value of type integer. Float indicates that theattribute value is a numeric value of type floating point. The valid integerand float values are indicated in Possible Values.Use the imgSetCameraAttributeString andimgGetCameraAttributeString functions to set and get the value ofString, Float and Integer attributes. Use theimgSetCameraAttributeNumeric andimgGetCameraAttributeNumeric functions to set and get the value ofFloat and Integer attributes.Note The spelling and syntax of the Attribute Name and string values must match thecamera attribute file exactly.NI-IMAQ Status SignalsNI-IMAQ has several status signals that can be used to trigger thegeneration of a pulse or invoke a callback function. Acquisition inProgress indicates that the board is acquiring image data. This signal goesTRUE when the board initiates the acquisition either through a software orhardware triggered start. When the last piece of image data is transferred tomemory, this signal goes FALSE. If the acquisition is a sequence,acquisition in progress will stay TRUE throughout the acquisition until theentire sequence is completed. Acquisition Done is the reverse ofAcquisition in Progress. This signal goes TRUE when the last piece ofdata is transferred to memory indicating that the acquisition has completed.Frame Start and Frame Stop indicate the status of an acquisition on abuffer basis. Frame Start indicates that a buffer is being acquired. Thissignal goes TRUE when the first valid pixel is detected by the board (evenif this pixel is not in the current region of interest). The signal goes FALSEwhen the last valid pixel is detected by the board. If the acquisition is asequence or a ring, Frame Start will pulse for every buffer in theacquisition. Frame Done is the reverse of Frame Start and indicates whenthe image is transferred from the camera to the IMAQ board.Buffer Complete indicates when the image data has been transferred tomemory and is available for image processing. Buffer Complete will goTRUE when the data in an image buffer has been transferred to memory(either onboard or system memory, depending on the acquisition).