Barcode Scanning
Data Matrix is a two-dimensional, variable-size matrix symbology that is capable of supporting several different character sets, using up to 2,335 characters in any language. Since its invention in 1989, it has come into widespread use in a variety of industries, especially where small, high-capacity identification symbols are needed, such as with direct parts marking, electronics, and pharmaceuticals.
Data Matrix can be printed in black on a white background or in white on a black background.
There are two types of the Data Matrix symbology, based on the error checking and correction (ECC) methods they use:
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ECC 200, which uses the Reed-Solomon algorithm
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ECC 000, ECC 050, ECC 080, ECC 100, and ECC 140 (known collectively as ECC 000-140), which use convolutional error correction
ECC 200 is the recommended symbol to use. ECC 000-140 symbols should be used only in closed systems.
Data Matrix is defined in ISO/IEC 16022 Information technology - Automatic identification and data capture techniques - Data Matrix bar code symbology specification).
Symbol Structure
The symbol comprises the following elements:
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Data regions that contain square modules in an array
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Alignment patterns (for larger symbols)
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Finder pattern
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Quiet zone border
The finder pattern around the perimeter of the symbol consists of a solid line on the left and bottom edges and a pattern of alternating black and white modules along the right and top edges.
ECC 200 symbols have even numbers of rows and columns and can be either square or rectangular. ECC 000-140 symbols have odd numbers of rows and columns and are square.
Character Set
This symbology supports all 256 ASCII characters, all ISO characters, and all Extended Binary Coded Decimal Interchange Code (EBCDIC) characters.
Error Correction
Data Matrix ECC 200 symbols use the Reed-Solomon algorithm for error correction. Data Matrix ECC 000-140 symbols use convolutional error correction and optionally only error detection.
Dimensions
The size of a Data Matrix symbol depends on the amount of data that is entered. If ECC 000-140 is used, the symbol size in modules can be from 9 x 9 to 49 x 49, with an odd number of rows and columns. If ECC 200 is used, the symbol size in modules can be anywhere from 10 x 10 to 144 x 144, with an even number of rows and columns. It is possible for an ECC 200 symbol to have more columns than rows and therefore have a rectangular shape.
Data Matrix requires a one-module-wide quiet zone on all sides.