Bar Code Traceability

Data Matrix 2D Barcode – DPM (DIRECT PART MARKING)
	Data Matrix is a two-dimensional matrix symbology consisting of black and white square modules arranged in either a square or rectangular pattern. The ECC 200 version of the symbol utilizes Reed-Solomon error correction to ensure data reliability. A Data Matrix symbol can store up to 2335 alphanumeric characters.
Applications One of the most popular applications for Data Matrix are direct part laser marking including small items such as integrated circuits and printed circuit boards and larger parts for the automotive, aeronautical and military. These applications make use of the code’s ability to encode approximately fifty characters of data in a symbol 2 or 3mm square and the fact that the code can be read with only a 20 percent contrast ratio. Benefits Data Matrix is designed to pack a lot of information in a very small space. Since the information is encoded by absolute dot position rather relative dot position, it is not as susceptible to printing defects as are traditional linear barcodes. Readers 2D barcode CCD reader scanners with Data Matrix support are required for reading Data Matrix. Technical Specifications Data Matrix encodes information in a machine-readable binary code that is dynamically variable in size, format and density. The coding scheme has a high level of redundancy with the data "scattered" throughout the symbol. This allows the symbol to be read correctly even if part of it is missing. The binary code is formed as a matrix. Each binary code symbol has two adjacent sides printed as solid bars, while the remaining adjacent sides are printed as a series of equally spaced square dots. These patterns are used to determine the size, the orientation and the printing density of the symbol. Two main subsets of Data Matrix symbols exist. First subset is the conventional coding for error correction that was used in the initial installations of Data Matrix systems. These versions are referenced from ECC-000 to ECC-140. The second subset is referenced as ECC-200 and uses Reed-Solomon error correction techniques. ECC-000 to 140 symbols all have an odd number of modules along each square side. ECC-200 symbols have an even number of modules on each side. Maximum data capacity of an ECC-200 symbol is 3116 numeric digits, or 2335 alphanumeric characters, in 144 symbol modules.
Direct Part Marking Definition: Direct Part Marking (DPM) is a technology used to produce two different surface conditions directly on the surface of a part. These markings can be created by laser marking, molding, dot peening, Concern: Traditional print quality measures are based on the assumption that there will be a measurable difference between dark and light elements of a symbol. Because DPM symbols frequently do not have sufficient contrast between elements intended to be dark and light, it is often necessary to provide specialized lighting in order to produce highlights or shadows in order to distinguish the various elements of the symbol. (See examples below.) Table of Contents: Reading Data Matrix bar codes with missing information Background Example Demo Code BACKGROUND: 2-D barcodes like Data Matrix are being used extensively in several industries such as automotive, aerospace, consumer goods, electronics, semiconductor, and life sciences. Major benefits of 2D codes over 1D barcodes include: Small size - more information can be packed into a smaller area Does not require precise sizing of individual elements (cells), because all elements are the same size. This is a major improvement over 1D barcodes, where bar thickness is critical to decoding. Built in error correction allows all information to be recovered even when a portion of the code is missing. DataMatrix codes have 3 basic areas of interest. The 2D code in Figure 1 below illustrates these regions. Next >>> 1 \| 2 \| 3 \| 4 \| 5 \| 6 \| 7