Bar code technology innovations continue to drive the creation of more sophisticated automation systems and also promote more capable solutions to information management challenges. Records managers are familiar with this technology in their experiences with bar codes printed on the adhesive labels used to inventory and track documents. They have seen bar code labels on file folders, storage boxes, retail merchandise, purchase requisitions, shipping containers, and mail envelopes. These small repositories of information are commonly used to identify records that will be more completely indexed in a database management system. By using bar code labels as miniature data storage media, automation systems can expand both the quantity and quality of the data input and the information processed. "To many people, automated data collection is nearly synonymous with bar code. There are other methods of keyless data entry, but the sheer ubiquitousness of bar code is testimony to its success."
Without bar code technology many automated records management systems would be far less capable of providing cost effective aids to managing documents. A common component of the justification of most automation systems is the assumption that many more records will be processed. Even a casual observer of such systems will realize that such assumptions occur due to the considerable data entry labor savings realized by scanning bar codes for the entry of data. Employee badge numbers, document numbers, and other alphanumeric data scanned into a database with bar code technology are processed more quickly and accurately than when data must be entered by "keyboarding." A good example of bar code technology is the PostNet bar code used by the U.S. Postal Service for delivering mail.
However, there are innovative and enterprising ways to use this information management medium that can enable improving organizational business processes. New bar code symbologies and recording methods allow increasingly larger amounts of more accurate data to be stored in what are called "portable data files." High resolution laser printers and more complex two- and three-dimensional data recording methodologies are making it possible to store an entire page of information in bar code format. Such bar codes can be faxed or transmitted electronically between locations as primitive electronic data interchange (EDI). As new means of using bar code technologies are incorporated into the workplace, records managers will want to assure they can contribute to any new professional challenges that may arise.
This discussion of bar code technology will cover symbologies, standards, reader technology, printer technology, and label media. It will also provide some references to available software and vendors. By having a good general understanding of this technology, records managers will be better positioned to participate in the design and implementation of information systems using this technology.
SYMBOLOGIES AND STANDARDS
So what exactly is a bar code? A standard "bar code can be thought of as a printed version of the Morse code, with narrow bars representing dots, and wide bars representing dashes. To read the information contained in a bar code symbol, a scanning device such as a light pen is moved across the symbol, from one side to the other..." This reading technique will vary depending on the particular nature and configuration of the bar code symbology. However, the basic idea is always the same - the alternating dark and light areas of the bar code represent data that can be quickly converted to digital format in a bar code reader or wand.
Other data entry technologies related in functionality to bar codes are optical character recognition, magnetic ink, magnetic strips, voice recognition, radio frequency tags, and smart cards. All these technologies have their own particular advantages; however, few are as inexpensive to implement in a reliable and flexible manner as is bar code technology.
Several standard bar code symbols are used in today's business applications. The Universal Product Code (UPC) is used commonly in the retail industry to identify products and manufacturers. Interleaved 2 of 5 is a numeric symbology, whereas Codabar uses both numbers and special characters. Code 39 is alphanumeric, using both numbers and characters. All symbologies differ in the width, spacing, and patterns of the alternating black bars and the white spaces between them. Additional symbologies include Code 128, Code 93, Code 49, and others. Each of these symbologies works best with differing business applications with Codabar and Code 39 having become two of the most commonly used approaches for library and records management applications.
Although these symbologies are usually seen as "standards," true bar code standards actually include application and print quality considerations. Concerns with label adhesion, bar width or spacing tolerances, and optical or reflectivity properties of labels are important. In addition, print resolution and quality can determine the ability of the bar code readers to interpret the data accurately. Many standards groups exist to guide the specification of bar code symbology, application format, and print quality. Such organizations include the American National Standards Institute, the Uniform Code Council, Department of Defense, American Paper Institute, and the United States Postal Service. Many trade and industry associations such as the Automotive Industry Action Group, the International Air Transport Association, and the Electronic Industries Associations also make industry specific recommendations.
BAR CODE READERS
Scanning a bar code label with a hand-held reader is the most visible action in operating a bar code enhanced automation system. This manual procedure is the part of the bar code system work flow that casual observers most readily recognize. It is also the primary interface of most users with the system and the area where technology enables the largest savings in labor over manual data entry. For these reasons, selection of bar code reader equipment is very important to the overall viability of the automation system and should be carefully planned and considered.
Bar code readers can be operated by hand, mounted below glass plates in checkout counters, or located along assembly lines for very mechanized scanning. Readers are available in many varying configurations, sizes, and prices. They can be "hand-held wands or light pens, hand-held lasers, stationary fixed beam scanners, stationary moving beam scanners, and photo diode array (PDA) bar code readers." The primary technology considerations in equipment selection "are the three functional elements: opto-electronics, signal conditioning, and digital processing." For bar code information to be communicated from the label to the computer system, the bar code symbol is illuminated with a light source and the reflected light is measured. Dark areas or bars reflect very little light, whereas the white spaces between the bars feed back more light to the reader's light detector. The alternating electrical signals generated in the bar code reader are converted to digital data for transmission to a computer system for processing.
A very common implementation of bar code readers is to attach them to computer terminals or even replace the terminal with a portable bar code reader. Since automation of data entry is a primary function of these devices, this arrangement is a natural integration. Data that would normally be typed is simply wanded into the database fields and appears on the screen as if entered by keyboard operator. "Key operators enter data at an average rate of two to five characters per second. Bar code data entry rates often are 30 characters per second. The key operator averages one error in every 300 characters entered. This error rate can be reduced to one error in every 45 trillion characters when bar coded date entry is used."
Readers can be attached to computers or their terminals through several configurations. Direct transmission of data from the reader to the host computer is possible, or the information may be displayed on a computer screen for validation by an operator prior to acceptance and commitment of the data to the computer system's database. Completely portable devices are available for batch loading of data into a local reader's memory buffer. The data is transmitted later over telecommunications lines or by radio signals to the host processor for batch upload into the system. Such portable readers are potentially less expensive than complete terminals or microcomputers and can use small visual displays and/or keyboards for data validation or executing custom programs. Additional technical specification issues for selecting bar code reading equipment are the particular light wave length read, label light reflectance requirements, bar resolution needed, and depth of field required for accurate operation.
Some bar code readers also work with radio frequency identification (RFID) tags. These intelligent tags can be programmed with several thousand characters of information, that can be reprogrammed as the data needs to be changed. Energy created by the portable reader is directed at the tag. Once energized, the tag emits radio frequency information back to reader over a considerable distance, making it possible to track moving items if needed. Now being used in industrial applications, this technology could also be applied to large records centers. The contents of boxes could be altered, the attached RFID tag updated, and then an inventory conducted without the necessity of climbing shelves and ladders to inspect individual boxes of records.
BAR CODE PRINTING
To select a bar code reader is to have jumped only one of the hurdles in the acquisition of technology hardware. An important consideration is that the morale of the data entry staff will decline if they must constantly re-wand bar codes due to labels being hard to read. The quality of the bar code labels will determine the accuracy of the data entered and the rate at which data can be transmitted to the database. Many automation systems will need printers capable of printing very high quality bar code labels.
This close interplay between bar code symbology, reader capability, and label resolution is the subject of much research and development. As an example of one research effort, "Stacked bar code symbologies, like Code 49, are not recommended for automated ammunition and rearm supply applications. The data content for a Code 49 symbol is limited to only 49 characters. Without error correction capabilities, stacked bar code systems depend on symbol print quality for success. Moving beam scanners used for stacked bar codes cannot reliably capture machine-readable data from symbols moving at high speed." Each new application of bar code technology has new requirements for the label media and symbology used and the capabilities of each technology will change over time with new research and development. Print quality will always be extremely important for applications where accurate inventories must be performed under special conditions.
The actual printing of bar code labels by different printer technologies has been studied extensively. Good text printers do not necessarily make good printers for bar code labels. "A round dot produces a bar with a scalloped edge, harder for the bar code reader to read, but it makes a human readable character that is more pleasing to the eye than the harsh corners of a square dot. Square dots make better bar codes while round dots are better suited for text documents."
Dot matrix printers can be used for printing bar code labels, especially if overprinting is used to smooth out bar edges. However, due to limitations in the resolution of their print heads, they are best limited to low resolution reader applications. Direct thermal and thermal transfer printers are well adapted to specific applications where burning the bar code into the label permanently or using bright colors is advantageous. Ink jet printers can be used for printing bar codes if the media used does not allow the ink to be absorbed to the point of causing loss of print resolution. Laser printers are increasingly used to print bar codes due to their high resolution and excellent print quality. A dedicated laser printer that can feed continuous pin-fed label forms is best. Such printers allow one to avoid the jamming difFiculties associated with feeding label sheets through the normal friction feed mechanisms of most laser printers, as well as avoiding constant paper tray loading of single sheet label stock.
Additional printing requirements for bar code labels often include the generation of standard text characters, type of differing font sizes, or graphics. This additional information on a bar code enhances its usefulness or friendliness. Many job tasks require the creation of occasional single bar code labels. Since standard text printers are expected to feed standard sizes of sheet paper, they are often not suitable for such a task. Using such a printer one might expect to print numerous labels on one sheet of full size paper. For these applications, a dedicated label printer is more cost effective. In any case, the software selected should meet a well-defined set of business requirements. "Be sure the label software supports your printer's capabilities ... the software written to control a printer can only use the features that the manufacturer has engineered into that printer."
Media selection should be performed based on the application requirements. Bar code labels are customized for each application depending on several operational and environmental considerations. The paper or laminated media on which bar codes are printed determines the level of bar code resolution possible with a given printer technology. The density of the information on the labels must be acceptable for the resolution of the bar code reader.
Background light in the environment, the scanning rate, and the shape of the reader's scanning beam width affect the best size and reflectivity of the label media. The orientation and position of the scanner relative to the label can also determine label design as label reflectivity requirements may change depending on the angle at which a label is read. For harsh operating environments, label media must often resist temperature extremes, corrosive chemicals, or assaults by adverse weather conditions. Special adhesives are available to assure that labels are not lost. Label life expectancy may call for the use of special compositions of laminated media. "The key to selecting the right bar code label is knowing exactly what your labels have to endure before and after they reach their destination."
Systems that use bar code labels with serial numbers produced commercially off-site in mass quantities still must assure quality labels are produced. A possible advantage of having labels produced commercially is that one is more likely to be able to afford the use of color, special paper stock, or extremely large or small label sizes. Very large labels, for instance, are readable at a greater distance from the object to which the label is attached. Label longevity should exceed or match the lifetime of the item or document to which it is attached. Adequate inventories of label stock are best ordered in advance to assure an adequate number are on-hand to meet item processing requirements. The nature and type of label stock will have a great procedural impact on staff training or the methods that are planned for applying the labels to each item.
SYSTEMS AND SOFTWARE IMPACTS
As increasing numbers of business applications use bar code technology, concerns will arise about data security. These "portable data files" will contain growing volumes of information as the ability of advanced bar coding techniques allows packing more information into each label. Since the label itself becomes the information base, actual connection to a computer host could become unnecessary. "Purchase orders may be faxed with the information encoded in electronic data interchange (EDI) format." Character transmission is sufficiently accurate that error rates can easily average less that 1 character substitution error in 10.5 million characters read. Considerable testing has shown that "these new high-capacity codes are quite reliable for most applications."
Document processing applications are an excellent opportunity for bar code technology, including the tracking of sensitive documents. An example of such an application is the publishing, printing, and distribution of academic tests and testing programs. A bar code tracking system has been used by The Psychological Corporation (TPC) of San Antonio, Texas, to "label, record, verify, and track secure materials throughout the distribution and return processes. The expenditure for the system was justified in part by the system's capability to process more than 3.2 million booklets distributed by TPC in early 1992, The Secure Materials Identification and Tracking System provided by AccuSort functions in three distinct areas: secure package assembly, order fulfillment, and secure item log-in." The functional analogies of the operation of such a system to the tracking of sensitive or classified government documents should be apparent to any records manager.
New bar code symbologies are arising that use two and three dimensional representations of data and look like square boxes full of dots or black and white checkerboards. "These special codes are most often used in factory automation and document processing." Vericode, Double Identification, Data Matrix, and Phillips Dot Code are oriented toward reducing the overall paper work and administrative overhead required in performing business operations. Quite often these are warehousing or storage center operations that are closely analogous to the operations of any records storage center.
Bar codes will increasingly store much valuable information that flows throughout many business systems. Most of the resources that are tracked by bar code enabled automation systems have associated correspondence, forms, and other administrative paperwork that are stored and managed by records managers. Records managers and records center operators will want to consult standard reference resources[14,15] and occasionally search bar code specific Internet Web sites to keep abreast of bar code technology developments. Following are some examples of presently available Internet Web sites providing information about bar codes related scanning technologies:
http://www.skandata.com/ttf.html - has information on a software package (Skandata.ttf) that allows creating bar codes directly from Windows software such as Access, Excel, Word, FoxPro, WordPerfect, and other popular programs.
http://www.visionshape.com/introbar.html - an introduction to bar codes and imaging systems
http://www.abarcode.com/barcodes.htm#Contents - a Web site entitled Frequently Asked Questions About Bar Codes: A Bar Code Primer.
http://www.globalscan.com/barcode.htm - bar code and point of sale equipment Web Site for Global Scan Technologies wholesale distributors.
http://www.riversedge.com - PostNet bar code fonts software by River's Edge.
http://www.xpoint.com - FormsXpress/UNIX 2.0 software by Xpoint Corporation.
http://www.textware.com - FormWare 1.0 software by TextWare Corporation.
http://www.postalsoft.com - Postware and Postware Plus Software 5.0 by Postalsoft, Inc.
http://www.kofax.com - Ascent Capture 1.2 software by Kofax Image Products.
http://www.tharo.com/tharo/ - EASYLABEL software by Tharo Systems Inc.
http://www.zebra.com/ - Barcode Anything software by Zebra Technologies.
1. Sam Dickey, "Keyless entry," MIDRANGE Systems, June 14, 1996, 9(9), p. 56.
2. Roger C. Palmer, The Bar Code Book, Helmets Publishing, Inc., Peterborough, NH, 1991.
3. Palmer, p. 4
4. Craig K. Harmon and Russ Adams, Reading Between the Lines - An Introduction to Bar Code Technology, Helmers Publishing, Inc., Peterborough, NH, 1989, p. 91.
5. Harmon, p. 128.
6. Gary Forger, "RFID: Poised for breakthroughs in industrial applications," Scan Tech News, May 1997, p. S-15.
7. Bradley S. Well, Automatic Ammunition Identification Technology Test Report for Datamatrix and Code 49 Symbologies, ORNL/TM-12330, Martin Marietta Energy Systems, Oak Ridge, TN, March 1993, p. 51.
8. Ernest E. Campbell, Bar Code Printing, Market Resources, Sandy, Utah, 1991, p. 5.15.2.
9. Mary C. S. Langen, "Get The Right Label Printing Package," IDSystems, 17(4), April 1997, p. 50.
10. Ann Marie Cook, "Ensuring Bar Code Label Quality," IDSystems, 17(4), April 1997, p. 52.
11. Roger S. Vincent, "Portable Data Files - Can You Trust Them?," EDI WORLD, November, 1993, p. 9.
12. Donald DeLash, "Passing the Security Test," IDSystems, 13(2), February, 1993, p. 34.
13. Craig K. Harmon, "Cures for the Common Code - Special-purpose codes and their applications," IDSystems, April, 1993, p. 24.
14. Harry E. Burke, Automating Management Information Systems - Principles of Barcode Applications, Vol. 1, Van Nostrand Reinhold, New York, 1990.
15. Robert D. La Moreaux, Barcodes and Other Automatic Identification Systems, Technomic Publishing Company, 1995.…