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2-D Data Matrix code is
rapidly becoming the accepted method of direct part marking for most
aircraft and medical device manufacturing. By arranging a grid of black and white checker board-like cells a code can be created that is capable of holding substantially more data in a smaller area than the conventional bar code. |
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![]() 2-D Data Matrix Example |
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Choosing the right two dimensional code for your application requires decisions on: þ Physical space availability þ Contrast issues þ Printing technology (laser marking, dot peening, etc.) þ Scanner/Reader requirements þ Cost considerations þ Mil-Std-130M compliance All-Marks provides equipment to print Mil-Std-130M compliant 2D codes. In addition, we can provide integrated 2D code readers from such major suppliers as Siemens, Ci-Matrix, Microscan, DVT, Cognex and SICK as well as recommend the optimum hand held readers for your application. Background Information Linear or one-dimensional bar codes are limited in the amount of information that can be contained within the code. Other technologies, such as magnetic stripe or RF tags can hold more information but are more expensive to implement. In an effort to develop bar code symbologies that would hold more information, stacked codes were developed. Stacked codes are linear bar codes printed one above the other to form a single symbol. These codes could be read by conventional reading equipment, such as laser or CCD handheld scanners. Some examples of stacked codes are Code 49, Code 16K and PDF417. To increase the density of information even further, matrix codes were developed. Matrix codes encode information using fixed width light and dark cells and also utilize sophisticated error/erasure correction algorithms to compensate for lost or missing data, extraneous marks, or code damage. There is usually some standard locator pattern, that is part of the image, to assure correct orientation when decoding the symbol. This means that print quality and contrast are much less critical than with 1-D bar codes or stacked bar codes. In fact, matrix codes can be applied directly to silicon wafers, PCBs, automotive components, or other applications where paper labels are inappropriate. Since they are not really "barcodes" anymore, conventional scanners can no longer read these codes. They are normally read by scanners using two-dimensional CCD devices that can capture an image of the entire symbol. Examples of matrix codes include Data Matrix, Maxicode, Aztec Code, PDF 417, QR Code and Snowflake.
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