Barcode SymbologyWhat is a symbology?A symbology is basically an alphabet. Different patterns of bars represent each "letter" in the alphabet. For most barcode systems, patterns represent numbers (0-9) and some control characters. A well-defined symbology is needed so that writers and readers of barcodes can communicate in a system. What character sets can a symbology have? A symbology including numbers only (and control) is called Numeric. A symbology including numbers, letters, and control is called Alpha-Numeric. A symbology including all 128 ASCII characters (the characters used by computers including punctuation, etc.) is called a Full ASCII symbology. How do you tell where the characters are in a barcode? There are two types of bar codes, discrete and continuous. In a discrete barcode, the bars representing each character are separated by a large gap, called intercharacter spacing. Each character itself begins and ends with a bar. The intercharacter spacing contains no information. Discrete barcodes make each character easier to find, but take up more space to print as well. Discrete barcodes have higher tolerance for low print quality. In a continuous barcode, the end of one charater is the beginning of the next. There is no spacing between characters. Continuous barcodes take up less space but require a bit more quality in printing. Back |