The most common use of Code 128 is for shipping labels. Code 128 is also used on ID cards.
Code 128 is one of the most efficient general-purpose barcode. It can handle any data and encodes the barcode in a relatively lot smaller space by using various compression techniques.
Being a high density barcode, Code 128 cannot be read easily using low resolution scanners.
Code 128 barcode is an alpha-numeric, variable-length, high-density code . Code 128 has 106 different bar and space patterns and each pattern can have one of the three different meanings, depending on which of the three different character sets is employed. Special start characters tell the reader which of the character sets is initially being used and three special shift codes permit changing character sets inside a symbol. Start Code A allows encoding standard alpha-numeric keyboard characters plus control characters and special characters. Start Code B includes all standard alpha-numeric keyboard characters plus lower case alpha and special characters. Start Code C includes a set of 100 digit pairs from 00 to 99 and can be used to double the density of encoding numeric-only data. Code 128 also employs a check digit for data security.
Code 128 data can be of any length. A Code 128 barcode consists of a leading quiet zone, one of the three start codes, the data itself, a check character, a stop character, and a trailing quiet zone.
If you need to generate a numeric only barcode with an even number of characters try using Code 128 C, it will produce a very dense barcode for you. Start Code C includes a set of 100 digit pairs from 00 to 99 and can be used to double the density of encoding numeric-only data.
Code 128 also allows encoding of four special function codes (FNC1 - FNC4). The FNC codes define instructions for the barcode reader. The meaning of function code FNC1 and FNC4 were originally left open for application specific purposes. Recently an agreement was made between Automatic Identification Manufacturers Association. (AIM) and European Article Numbering Association(EAN) to reserve FNC1 for use in EAN applications. FNC4 remains available for use in closed system applications. FNC2 is used to instruct a barcode reader to concatenate the message in a barcode symbol with the message in the next symbol. FNC3 is used to instruct a barcode reader to perform a reset. When FNC3 is encoded anywhere in a symbol, any data contained in the symbol is also discarded.
One can use Label Flow™ barcode software for printing shipping labels with code 128 barcodes or use Asset Track (asset tracking software) for labeling and tracking inventory with code 128 labels or use ID Flow™ ID card software for printing ID cards with code 128 barcodes.