Instrument Readers
Owning Palette: Machine VisionInstalled With: NI Vision Development ModuleUse the Instrument Reader VIs to develop applications that require reading from seven-segment displays, meters or gauges, or one-dimensional barcodes.
| Palette Object | Description |
|---|---|
| IMAQ Get LCD ROI |
Use this VI to locate a seven-segment display within an area of interest. The display can contain multiple digits. To find the area of each digit, all of the segments of the seven-segment indicator must be activated. |
| IMAQ Read LCD |
Reads an LCD display in an input image using the descriptor of the ROI calculated by the IMAQ Get LCD ROI. IMAQ Read LCD returns the number as a double and as a string. The Segments status output indicates whether the number is recognized properly or any of the digits are not recognized fully. This output returns the status of each of the digits in the display. This VI reads LCD or LED indicators and tolerates light drift. |
| IMAQ Read Single Digit |
Reads a single seven-segment digit from a rectangular area of interest drawn around this digit. This VI reads LCD and LED indicators. It returns a value as a string and a cluster containing the state of each segment (ON or OFF). |
| IMAQ Get Meter |
Calibrates the meter or gauge using the initial and the full-scale position of the needle. It calculates the position of the base of the needle and the arc traced by the tip of the needle. |
| IMAQ Read Meter |
Reads the position of the needle using the base of the needle and the array of the points of the arc traced by the tip of the needle. This VI reads meters with a dark needle on a light background or with a light needle on a dark background. It returns the location of the tip of the needle as a percentage of the full range of the meter. |
| IMAQ Get Meter 2 |
Calibrates the meter or gauge using three points on the meter: the base of the needle, the tip of the needle at its initial position, and the tip of the needle at its full-scale position. It calculates the position of the points along the arc covered by the tip of the needle. |
| IMAQ Read QR Code |
Locates and then reads the value encoded in a QR code. |
| IMAQ Read Barcode |
Reads common 1D barcode types, including Codabar, Code 39, Code 93, Code 128, EAN 8, EAN 13, Interleaved 2 of 5, MSI, UPCA, Pharmacode, and RSS Limited. |
| IMAQ Read Data Matrix Barcode 2 |
Locates and then reads the value encoded in a Data Matrix barcode. |
| IMAQ Grade Data Matrix Barcode AIM |
Grades a Data Matrix barcode using the AIM Print Quality metrics included in the ISO 16022 specification. You must first prepare this Data Matrix barcode image for grading using IMAQ Read Data Matrix Barcode 2. |
| IMAQ Read PDF417 Barcode |
Reads values encoded into a PDF417 barcode. You can compare the decoded data to a reference string or check whether the data contains a specific pattern. |