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2-D bar codes: more options, new ways to manage inventory data.

Even if you have not yet seen many two-dimensional bar codes in use, don't overlook them as a viable data collection tool.

In fact, 2-D bar codes such as PDF417, MaxiCode, and Data Matrix are examples of new technology very much in tune with the times. From the shop floor to the shipping/receiving dock, managers increasingly require immediate access to complete databases about inventory. They also want that information in a format That requires only minimal real estate on that unit of inventory.

Two-dimensional bar codes are built to do all of that. They pack up to 2,500 characters into printed symbols measuring 1 sq in. or smaller. The data can be scanned at a workstation and almost instantaneously displayed on a local terminal.

To say the least, activity in these portable data files is strong. During the past 18 months, several 2-D bar codes have been unveiled, joining others already available. Several have also been placed in the public domain for unrestricted use.

Meanwhile, the trade association AIM USA is busy creating standards for 2-D symbologies. Standards have been released recently for one of the most prominent ones, PDF417. By the end of the year, AIM USA expects to complete standards for Data Matrix and MaxiCode.

As if those developments were not enough, new scanners, both hand held and fixed position, have been announced at a steadily increasing rate. Until 18 months ago, scanner options were severely limited.

Printers able to run 2-D labels have always been more available than scanners. And now there are more models than ever.

All of this activity is creating a burst of new applications. Products as diverse as eyeglass lenses, overnight packages, pallet loads, and semiconductors are being identified and tracked with 2-D bar codes.

Setting the baseline

From their beginning nearly 10 years ago with the introduction of code 49, these symbologies have been different from their predecessors such as Interleaved 2 of 5, and code 39.

A conventional bar code acts as a unique identifying license plate for inventory. Only a small number of characters can be printed in this linear format before the bar code becomes too long for practical use. And once that bar code is scanned, a computer-resident database must be accessed to obtain any details about the inventory.

In direct contrast, 2-D symbologies are intended to be small, stand-alone databases. While there are several ways to encode data in such a compact format, there are two generally accepted types of 2-D symbologies.

Stacked symbologies build (stack) rows of bars and spaces, placing them one on top of the other. Both laser and charge coupled device (CCD) scanners read the data by moving across the symbol in a consistent orientation. Examples are PDF417 and Code 49.

Matrix symbologies dispense with bars and spaces and encode data in a checker-board pattern of shapes from squares to hexagons and circles. Each symbology uses a finder pattern such as a bull's eye (MaxiCode) or "L" perimeter (Data Matrix) to orient the scanner. As a result, there is no right-side-up or upside-down orientation to these symbols. They can be read by omni-directional and CCD scanners at any angle.

Some stacked and matrix symbologies encode only alphanumeric characters or simple ASCII. Others encode binary data that makes it possible to include photographs and even fingerprints. For instance, PDF417 was used on identification cards at the Atlanta Olympics and included the person's photo in the code. The U.S. military is also using PDF417 on personnel i.d. cards and the Chinese government is doing the same with Data Matrix.

The prominent symbologies

At this point, PDF417, MaxiCode and Data Matrix are the most widely used and recognized 2-D symbologies.

Following on the heels of AIM USA's development of standards for those three, hardware development has been rapid.

Scanners are now available from Symbol Technologies, Welch Allyn, Intermec, Metanetics Impact Technologies, I.D. Matrix, Computer Identics, Accu-Sort, and CSPI/Vision Systems, to name the most active.

Most printer suppliers also support 2-D bar codes on a wide range of equipment. While the majority of the focus is on thermal/thermal transfer printers, high-resolution ink jet systems are coding eyeglass lenses with Data Matrix.

For end users, various industry organizations have made recommendations for use of the three leading symbologies.

For instance, the American National Standards Institute MH10.8 committee recommends PDF417 for shipping/EDI labels and MaxiCode for sortation applications. The Automotive Industry Action Group (AIAG) has made similar recommendations plus it recommends use of Data Matrix for small parts marking.

Simultaneously, development work in 2-D bar codes continues.

For instance, SuperCode encodes large amounts of data and is expected to meet various shipping/EDI requirements as does PDF417. Matrix symbology Aztec Code was designed to maximize ease of printing and decoding of small to large amounts of data. Ultracode is the first 2-D symbology that can be printed in various colors and accommodates all natural languages. Details on these public domain symbologies are detailed in the box on the previous page.

Some other recently developed symbologies require either a license or have some proprietary restrictions on their use. These include 3-DI (Lynn Ltd., Ann Arbor, Mich.), and CP Code (CP Tron Inc., El Cerrito, Calif.)

Proprietary codes especially developed for industrial applications include ArrayTag (ArrayTech Systems, Victoria, British Columbia, Canada) and MiniCode (Omniplanar, Princeton, N.J.). The former is optimized for data collection at a distance or under variable lighting. MiniCode is for sortation applications and shipping manifests.

In short, 2-D bar codes may still be in the early stages of acceptance by industry, but there's little doubt they have a significant future.
     Average annual growth
      in 2-D bar code use,
         1995 to 2000

Automotive        110%
Wholesaling       105%
Electronics        85%
Pharmaceuticals    82%
Food/beverage      80%
Retail             62%
Aerospace          51%
Transportation      33%
1995 = $14.9 million 2000 = $200 million

Source: Venture Development Corp.
COPYRIGHT 1996 Peerless Media, LLC
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Copyright 1996 Gale, Cengage Learning. All rights reserved.

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Author:Forger, Gary
Publication:Modern Materials Handling
Date:Sep 1, 1996
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