For various decades, the barcode has been a very useful data exchange tool in the industry, owing to its simplicity of use and data retrieval as well as due to its unquestionable profitability. However, it suffers from a certain fragility of the printing quality for applications in aggressive environments and the amount of data to be recorded on the products has increased significantly, exceeding the bar code capacity.

The marking technology which is gaining ground is 2D Coding. Whereas a conventional barcode represents the information in a single direction, two-dimensional coding widens the reach, by using an X-Y data matrix. With a standard barcode, the only way to add information consists in increasing the length of the barcode, making it harder to read. Moreover, a very high contrast (80% up) is required to ensure correct reading of the code. Also, it does not take long for the barcode to deteriorate and even to become completely illegible. By contrast, 2D coding can contain a much greater quantity of data. If a barcode can store 20 bytes of information on a given area, 2D coding will store 2000 bytes on the same area. Additionally, 2D coding features an error correction system and needs only 20% contrast to ensure correct reading.

Data Matrix^TM is the 2D coding system developed by RVSI Acuity CiMatrix. It is a public domain code which is converting itself into a standard. Its major characteristics include:

• The possibility of using a square or a rectangular matrix
• A storage of 1 to 3116 numerals or 2335 alphanumeric characters
• Reed-Solomon error correction, with data redundancy
• Excellent compatibility with dot markers for marking the code on metals, wood, plastics, etc.

One of its most frequent applications is the marking of codes in reduced spaces, such as on printed circuits, master boards, etc. The code is read by a CCD of a video camera. Being an infinitely scalable symbol, it can be read from any distance, subject to an adequate combination of the matrix size and reading device.