Bar Code Primer

Bar codes play a large part in many data collection systems. Data Net offers a wide range of bar code data collection products. Understanding how bar codes and the devices that create and read them fit into your particular data collection solution can be daunting. Fortunately, Data Net is an expert in the field and can help you sort out information from hype. The following sections provide a gentle introduction to bar codes, bar code readers, bar code printers and other technologies associated with bar codes. You can skip to the section you are interested in by clicking on the list below:

Industrial Uses for Bar Codes
Bar Code Symbologies
Bar Code Generation Software
Bar Code Printers
Bar Code Scanners
Industrial Uses for Bar Codes

Bar Codes are used in many industries and for many purposes. Some industries have specialized requirements for bar codes. The most common application for bar codes is in retail stores where UPC bar codes appear on nearly all products. Bar codes have wide application in industrial settings. The list below summarizes some of the industries that use bar codes and a few of the applications they have for bar codes:

Industries
Applications
Aerospace Asset Tracking/Tool Room
Automotive Auto Industry (AIAG) Labeling
Consumer Products/Electronics Circuit Board Identification
Pharmaceuticals Compliance Labeling / Standards
Textiles Chemical Drum Labeling
Pulp & Paper Roll and Pallet Labeling
Food & Beverage Shipping and Distribution Labeling
Retail Stores Compliance Labeling
Transportation Receiving and Cross-Docking

If you have a product you wish to sell in a store and need a UPC bar code, please visit the Uniform Code Council, Inc.
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Bar Code Symbologies

Bar codes have come a long way since their introduction in 1959. Today, they can be found on nearly all products you purchase in the store. There's probably a bar code on a product on your desk. Your computer probably has a bar code on it somewhere.

Bar codes come in various types, sizes and formats. The most common and recognizable type of bar code is the 'one-dimensional' linear bar code. One-dimensional bar code symbologies include UPC (the bar codes you see on groceries), code 128 and code 3 of 9. Two-dimensional bar codes are a relatively recent development. These special purpose bar codes can store a great deal of information in a small space. Two-dimensional bar codes include PDF 417, Data Matrix and Maxicode. There are even special three-dimensional bar codes called Bumpy Bar Codes™. The images below show some common bar code symbologies:

Bar Code Symbologies: Code 128, Codabar, QR Code, Maxicode, Data Matrix, UPCA, PDF 417, Code 12 of 5

How do you know which bar code to use with your application? Certain industries have standardized on certain symbologies (and sometimes even the format of the entire bar code label). Certain applications require specialized bar codes. Understanding which bar codes to use with your application is complicated by the fact that not all bar code symbologies can be read by all bar code scanners. Certain symbologies require special scanners or readers. The table below lists many of the common bar code symbologies, their typical industry and the type of reader required:

Bar Code
Industry
Reader/Scanner
Code 3 of 9 Mfg Laser, CCD, Wand, Imager
UCC/EAN 128 Mfg, Retail Laser, CCD, Wand, Imager
Code 128 Mfg, Retail Laser, CCD, Wand, Imager
UPC Retail Laser, CCD, Wand, Imager
EAN European Laser, CCD, Wand, Imager
Interleave 2 of 5 Mfg, Retail Laser, CCD, Wand, Imager
PDF 417 Mfg Modified Laser, CCD, Imager
Data Matrix 2D Mfg Imager
Bumpy Bar Code 3D Mfg Special Reader
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Bar Code Generation Software

One way to generate bar codes is to use special purpose bar code generation software. There are many different software packages to design and print bar codes. It is not necessary to print your own bar codes. It is possible to order pre-printed bar code labels. If you do require the ability to generate custom bar codes on demand you will need to know what platform you will be printing from. The table below lists some popular bar code design and printing software and the platforms they work with.

Bar Code Software
Platform
Codesoft (www.teklynx.com) PC based
Easy Label (www.easylabel.com) PC based
BAR-ONE (www.zebra.com) PC based
TL Ashford (www.tlashford.com) AS/400
BarTender (www.seagullscientific.com) PC based
LabelMatrix (www.teklynx.com) PC based
LabelVision (www.labelvision.com) PC based
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Bar Code Printers

Once you have designed a bar code label you will have to decide how to print it. Depending on your application you may need to print bar codes on plain paper, special label stock or directly onto box or item. When it comes to bar code printers there many, many choices. Because of the complexity of matching printer, ribbon, label medium, label width and application it is impossible to provide a comprehensive description here. A Data Net specialist can help you find the correct combination for your needs.

As a general overview, most bar code printers are either direct thermal printers or thermal transfer printers. Direct thermal printers use special label stock that turns black when heated by the print head inside the printer. Thermal transfer printers are similar to direct thermal printers in that they include a print head that heats up. However, thermal transfer printers heat a ribbon to transfer the image to the label stock. Direct thermal labels tend to fade with age and will darken if exposed to heat or strong sunlight. Thermal transfer printers can cost more to operate because of the extra cost of the ribbon; however, there are many choices for ribbon composition and color, allowing greater flexibility in label output.

Bar code printers come in a variety of shapes and sizes, including portable printers. Data Net can help you find the right printer for your application.

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Bar Code Scanners

Bar code scanners come in many different shapes, sizes and capabilities. The simplest bar codes scanners are called 'wands'. Because of the small size, lack of moving parts and simple construction wands are the most cost effective bar code scanners. Other bar code scanning technologies include laser, CCD and imaging scanners. Laser scanners work by rapidly passing a laser beam across the bar code to be scanned. Detectors inside the scanner sense the light and dark bars that make up the bar code. CCD scanners work off a similar principle but have no moving parts. Bright light emitting diodes (LEDs) take the place of the moving laser beam. Imaging scanners are the most complex scanners. Imaging scanners contain a special detector that takes a picture of the bar code to be scanned and then decodes it internally. The following table highlights some of the difference between these technologies:

Technology Strength Weakness Range
Wand Low cost Tethered, limited to 1-D bar codes Contact
Laser Scanning range Cost, most limited to 1-D bar codes, some PDF 417 Short to long
CCD Cost, reliability Scanning range, 1-D or PDF 417 Short
Imaging Reads 2-D bar codes, some have ability to capture images Cost Short

Bar code scanners can be separate peripherals that can be attached to a data collection terminal or PC or they can be incorporated directly into a data collection device. The best technology is the one that meets your needs. Data Net can assist you in choosing the correct device for your application.


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