Barcode

Data Matrix is one of the smallest and most dependable barcode symbologies(smaller than QR Code). The size difference of popular barcode types is compared in the Barcode Symbology Evaluation and Test Sheet.

GS1 Data Matrix barcode symbols do not encode the last digit of the GTIN, which is a check digit. If the full 14-digit GTIN is needed after reading the symbol, it may be generated with a MOD10 calculation.

According to GS1 specifications, the first FNC1 character should be decoded as "]d2" and any additional FNC1 characters will be decoded as (ASCII 29). The function is usually only visible when scanned with the Barcode Scanner ASCII String Decoder. Not all scanners properly decode the first FNC1 character as "]d2".

GS1 DataMatrix uses a special start combination to differentiate the GS1 DataMatrix symbol from the other Data Matrix ECC 200 symbols. This is achieved by using the Function 1 Symbol Character (FNC1) in the first position of the data encoded. It enables scanners to process the information according to the GS1 System Rules. 

The FNC1 is encoded in two separate ways within GS1 DataMatrix:

Start character (ASCII 232)

Field Separator (ASCII 29: )

When used as part of the special combination – use ASCII 232

When used as a field separator (see 2.2.2 Concatenation,) - ASCII 29 :

Using GS1 DataMatrix, it is possible to concatenate (chain together) discrete Application Identifier (AIs) and their data into a single symbol. When the AI data is of  pre-defined length, no field separator is required when the next Application Identifier and data are concatenated immediately after the last character of the previous AI data. Where the AI data is not of pre-defined length, it must be followed by a field separator when concatenating more AIs. 

Global Trade Item Number (GTIN) is an identifier for trade items developed by GS1. Such identifiers are used to look up product information in a database (often by inputting the number through a bar code scanner pointed at an actual product) which may belong to a retailer, manufacturer, collector, researcher, or other entity.

The Global Trade Item Number (GTIN) only identifies the product type or stock-keeping unit (SKU) rather than an individual instance of a particular product type. To ensure that an EPC always uniquely identifies an individual physical object, in the case of a GTIN, the EPC is constructed as a serialised Serialised Global Trade Item Number (SGTIN) by combining a GTIN product identifier with a unique serial number.

The Universal Product Code (UPC) is a barcode symbology. Its most common form, the UPC-A, consists of 12 numerical digits, which are uniquely assigned to each trade item.

An EAN-13 (European Article Number) barcode is a 13 digit (12 data and 1 check) barcoding standard which is a superset of the original 12-digit Universal Product Code (UPC) system developed in the United States.