Lexmark Forms Printer 2491 Technical Reference - Page 148

UPC-A and EAN-13 barcodes use a flag character for number system encoding and country code. Your printer provides the capability of printing the human readable form of this flag character either in the vertical center along the left side of the barcode, or under the barcode with the other human readable characters. Some barcodes use a check character, a character at a predetermined position within a barcode, whose value is computed by a mathematical algorithm. When the barcode is scanned, the scanner can check the data using the same algorithm to validate that the barcode was read correctly. Flag Character Human Readable Characters Check Character Each barcode type has a defined set of characters. Specific parameters for each barcode type, including their character set definitions, are covered in the Barcode Symbologies section beginning on page 153. Accessing the printer's resident barcode function requires sending two escape sequences to the printer: • Barcode setup command • Data transfer command The barcode function is explained in the following four sections: Barcode Setup Command Data Transfer Command Barcode Symbologies Notes on Barcoding Barcode Setup Command This command specifies all the necessary parameters to define the desired barcode symbology. Syntax: ESC [ f 6 0 k m s v1 v2 c Decimal: 27 91 102 6 0 k m s v1 v2 c Hex: 1B 5B 66 0 0 k m s v1 v2 c 60 148 Section 8: Barcodes