Despite grand plans for RFID, bar codes will continue to dominate data capture in the warehouse and plant for years to come. After all, bar codes are low-cost and proven. But that doesn't mean that either the technology or its use is static.

Three decades after bar codes debuted at a grocery checkout, the needs of end users of traditional linear bar codes continue to evolve. Easier to use and configure, greater versatility, wireless, and RFID-capable are just some of the key interests here.

In addition, there are new initiatives to take advantage of two-dimensional symbologies that are capable of carrying more information than a traditional linear bar code.

The U.S. Postal Service, for instance, is working on a single bar code that can carry all of the information about a parcel or letter. And the Army recently awarded a contract for advanced mobile computing that included a requirement to read Data Matrix codes.

In addition, both the automotive and aerospace industries have launched part marking programs that use 2-D bar codes to track the genealogy of a part to simplify a recall, for instance.

As the applications and expectations for bar codes expand, suppliers of bar code scanning devices are developing new innovations in laser scanners and imaging devices.

In the industrial world, scanners come in two form factors: handheld and fixed position. The former, often called a scanning gun, is typically connected to a fixed computer at a workstation or a mobile terminal that is either hand carried or mounted on a lift truck. Some portable terminals have the scanner built into the unit for ease of use. Fixed-position scanners are usually installed along or above a conveyor line or sortation system to automatically scan bar codes as cartons pass by.

Within those form factors, different technologies capture the information.

The most common is a laser that scans in a straight line. Lasers are used where the orientation of the bar code can be controlled, such as a worker aiming a handheld scanner directly at a bar code.

Raster scanning sends out multiple lines that sweep across a field where the bar code will appear. That allows for accurate reads even if the bar code isn't in the same position every time. A user can control the angle of the sweep and the width that it scans.

Omnidirectional scanning solutions are used where the orientation of a carton or bar code can't be controlled, like a sortation line. 'An omnidirectional scanner emits a light that can capture data in any direction,' says Jeff Osterhues, director, automatic identification, SICK (952-941-6780, www.sickusa.com). He adds that when arranged as a scanning tunnel, 'it can also capture data from the top, bottom, and sides of a carton.'

While laser scanning is most often associated with scanning linear bar codes, it can also be used to read two-dimensional bar codes such as PDF 417. Unlike a linear bar code which is a picket fence of data, 2-D symbols arrange data in a complex matrix that can store several thousand characters of data rather than a few.

To read this more dense collection of data, imaging devices are typically required. This digital camera-based technology reads an area and captures an image of a bar code, human readable information, like a signature, or even an object.

'A laser scanner gets a string of data,' says Don DeLash, vice president of sales for Accu-Sort (800-227-2633, www.accusort.com). 'With an imager, you can get an actual image. It can also detect boxes that are side by side, which is beyond traditional scanning devices.'

Parcel distributors and high-throughput retail distribution centers are increasingly turning to imaging technology to read labels and verify printed characters with optical character verification (OCV) technology.

The automotive industry is interested in imaging because of the added depth of information that can be added to a 2-D symbol. 'If you ever have a recall, automotive manufacturers only want to recall the affected parts,' says Bill Callahan, director of product marketing, Symbol Technologies (866-416-8545, www.symbol.com). 'With a 2-D bar code, you know not just that a door was produced, but when and where the door was produced.'

After 30 years of laser scanning, the performance of today's systems will meet most needs. Nevertheless, suppliers are still under pressure to further refine scanners.

'We're focusing on more rugged and reliable scanners,' says Callahan. 'That means devices with an IP64 rating for dust along with the ability to withstand multiple drops from six feet. This is important because these devices are constantly being bumped.'

The latest scanners are also easier to configure at start up. For example, fixed-position scanners once were programmed to read a bar code at the factory. 'We're now seeing scanners with programming software that allows the user to position the symbol in front of the scanner and it will auto-calibrate, which allows for quicker uptime,' says Matt Allen, product manager, Microscan Systems (425-226-5700, www.microscan.com).

They are also designed to be easier to install and maintain. 'We're embedding field BUS components directly into scanners that reduce cabling requirements and make it easy to connect to a factory network,' says Osterhues. 'And changing the laser diode is almost like changing a light bulb.'

Finally, the next generation of scanners is becoming more versatile. 'In the past, a long-range scanner that worked well from twenty feet away didn't work from two feet away,' says Richard Bauly, vice president of strategy and business development, Psion Teklogix (905-813-9900, www.psionteklogix.com). 'That meant you needed two different devices. Today, one device can handle both situations.'

While scanners capable of handling multiple read ranges are bulky for now, other new devices have been designed to be easier to handle, adds Tracy Hillstrom, product manager for data capture, Intermec (800-934-3163, www.intermec.com).

'We've developed a unique form factor that looks like a flashlight,' Hillstrom says. 'It easily disconnects and can be put away in a holster, belt clip, or sash when it's not in use.'

Cordless technology is also coming to the forefront, especially in lift truck-mounted scanning devices.

Improved Bluetooth technology, a technology that creates a wireless personal area network, is making this possible. 'In the past, it just wasn't economically feasible to replace a $30 cable with a new device, a reader, and batteries,' says Paul Denimarck, senior product manager, HHP (800-782-4263, www.hhp.com). 'With Bluetooth, we're seeing the emergence of a new generation of low-cost, cordless devices.'

Early devices had a range of about 30 feet. The next generation of Bluetooth cordless devices are expected to have a range of up to 100 feet.

The increased use of 2-D symbols is driving the demand for camera-based technology which takes a digital picture of the symbol. That opens up other possibilities beyond reading symbols such as capturing proof of delivery signatures or even a picture of a damaged carton.

'As recently as three years ago, image capture was relatively slow in comparison to traditional bar code data capture and much more expensive,' says Ron Caines, president and CEO, Symagery (613-592-2592, www.symagery.com), which builds image-based scanning engines for original equipment manufacturers. 'Today, the cost has come down and the speed of throughput has improved.'

Today's camera-based systems can support manufacturing line speeds of up to 7,200 parts per minute, adds Carl Gerst, manager of product marketing for ID products business unit, Cognex (508-650-3000, www.cognex.com). And, as with other bar code technologies, image-based readers are becoming easier to use.

For instance, some new handheld and fixed position readers feature an integrated lighting system. 'You can plug one in to your existing network, point it at a bar code, and it'll start reading,' says Gerst. 'Manufacturers can move forward on part traceability projects with confidence that the readers will read reliably and quickly.'

While bar codes still dominate, RFID is coming. As a result, leading suppliers like Symbol and Intermec are working on scanning devices that will be able to address laser scanning, imaging, and RFID in one device.

'The industry is moving toward a single handheld device that will be capable of interrogating an RFID tag, reading a bar code, and capturing a digital image,' says Caines of Symagery. 'It's not ready now, but we think you'll see these devices in 2005,' he adds.

Click on the icon to read more about image-based scanning - (I can see clearly now - April 2003)