RFID: Print and ship
There's more than one way to get an RFID tag on a carton. And they're all being tried right now.
By Bob Trebilcock, Editor at Large -- Modern Materials Handling, 1/1/2005
On the surface, printing and applying an RFID tag seems like it ought to be easy. The process, after all, utilizes printers and applicators similar to those that apply bar codes by the millions every day. And who gives bar code labeling a second thought?
But as a new world of product identification shifts into a higher gear this month at Wal-Mart and elsewhere, both end users and equipment suppliers are finding that there's more to RFID labels than meets the eye.
"This is a very young marketplace," says Mark Brown, vice president of business development and marketing for Lowry Computer Products (800-733-0210).
And with youth comes experimentation. Some end users are focused on simply printing combination bar code and RFID labels (smart labels), then applying them to cases and pallets by hand (slap and ship). At the other end of the spectrum are print/apply machines that automate the entire process. But these are the early days.
"The design of print engines and applicators is still at some level of flux because it's all so new," says Brown. "You're going to see a lot of system re-designs in 2005."
If that sounds like vendors and users alike are learning on the job, it's because they are. And it's not just a matter of printing and applying labels.
"There are a number of unique issues associated with encoding RFID tags that are not being adequately addressed by a lot of users," says Rick Fox, president of applicator provider FOX IV Technologies (724-387-3500).
Those issues cover the gamut from how to get rid of a bad tag to how a user allocates and manages millions of unique EPC product code numbers across multiple facilities. "As an industry, suppliers are still trying to answer those questions," Fox contends.
As users consider RFID labeling solutions there is one other caution to keep in mind: This technology is a tool, not a panacea.
"A printer solution can generate and manage the RFID data," says Jan Svoboda, RFID business unit manager for printer-maker Sato America (704-644-1650). "But it is not a remedy for bad practices."
A range of optionsA survey of the leading suppliers shows that, regardless of the specific technology used, there are four steps required to get a readable tag onto a carton or pallet.
- Unique product information is first translated into EPC data that will be encoded on the tag.
- That information is electronically written to the RFID tag. Simultaneously, it is printed on a bar code label or printed directly on a carton.
- The tag and label are then applied to a carton or pallet. Most users are working with labels that include an embedded RFID tag, known as a smart label.
- The applied tag is verified again to make sure it's still reading once on the carton.
Each of those steps has proved challenging. And companies participating in the Wal-Mart and Department of Defense pilots are taking a variety of approaches to printing and applying tags and labels (the drawing below details the anatomy of a smart label).
|
Anatomy of a Smart Label |
| 1. Bar code label - the top side of the smart label carries human readable print and bar code information, just like a traditional label.
2. RFID antenna - made from copper or aluminum, the antenna receives an electronic signal from an RFID reader. 3. RFID chip - The silicon chip contains memory, a capacitor, leads to attach to an antenna. 4. Label liner - The protective liner is automatically pealed away before a smart label is applied. |
A few early adopters (and very few by most accounts) are setting up systems to automate the process. The most common model involves delivering a pallet load to a separate work area that already has a bar code label identifying the product. The cases are de-palletized onto a conveyor, and the bar code label scanned. Then an automated printer/applicator prints and applies a smart label as cartons pass by. This process ties the case to both a customer and a specific order. At the other end of the conveyor, cases are re-palletized for shipment.
Other solutions encode and apply the RFID tag separately from the bar code label. This improves throughput and optimizes positioning of the RFID chip for readability. Meanwhile, the bar code label can be applied in a standard position for ease of scanning. Another scenario uses an ink jet printer to apply bar code data directly on each carton in a standard position while the RFID tag is applied separately for optimum readability.
At the other end of the spectrum is the minimalist approach. "These companies are printing a normal label with a blank RFID tag that they apply by hand," says Doug Hall, Intermec's director of printer and data capture marketing, (800-934-3163). "Then they scan a bar code by hand which tells the system what information to write onto the new smart label. "Some aren't even bothering with automatic readers, Hall adds. "They're just buying a hand-held reader to do auditing or testing," he says.
Others are bypassing the encoding process altogether by buying pre-encoded tags or smart labels.
"We're working with customers who e-mail us their serialized product data in an Excel spread sheet," says John Powell, vice president of service and system integration, Paxar (800-543-6650). "With that, we can pre-print, pre-encode, and verify the tags. For some it's a short-term solution."
Most users are somewhere in between. They're installing workstations equipped with a portable printer, where they print and encode smart labels that are then applied by hand.
Meanwhile, even some household names are tire-kicking the applicator market as they wait to see what retailers ultimately demand of them before placing an order.
Managing data
But the printing and application of labels is only part of the story. Whatever model is chosen, traditional UPC information needs to be serialized and translated into a format that can be written to an RFID chip before encoding a tag.
This requires a new software application, since warehouse management systems (WMS) and middleware solutions for bar code applications aren't designed to work with RFID tags. Several leading WMS suppliers have created RFID-compliance packages or are working with middleware applications that bolt to their software. Another approach is to use a smart printer with the middleware application built in. "A smart printer has intelligence onboard which allows it to be programmed to manipulate the data streams and communicate with a host system," explains Hall of Intermec. These printers can scan a UPC bar code label on the product and alter its structure to create an EPC number that is written to the tag. "The printer can proactively query the host system to get the EPC information, or you can store a database of EPC numbers in the printer," explains Sarah Schabacker, business development manager, Datamax (407-578-8007). Getting it right Several companies are using smart labels. In these setups, the label printer encodes the RFID tag, verifies the tag, and then prints a bar code label on the tag. Still others are doing those processes separately: encoding a stand-alone RFID tag and separately printing a bar code label or printing directly to a carton. There are several factors to consider when evaluating which solution is best. Some find it more economical to combine the two processes into one. Others have discovered that they get better performance when they place the RFID tag in a spot other than the prescribed location for the bar code label. And some users believe they get better throughput by applying the labels first, which is a relatively error-free process. Then the RFID tags are applied and verified to ensure an accurate read. Printer manufacturers are building flexibility into their units, especially around tag encoding. "Multi-protocol" printers, for instance, are designed to work with the Class 1, Class 0, 0+ and international tags currently available. "These allow a customer to use the best tag for each of their customers' applications," says Matt Ream, senior manager, RFID systems, Zebra Technologies (800-423-0422). There is also the issue of encoding only one tag at a time, says Powell of Paxar. "If you're printing 4-inch by 6-inch labels, it's not an issue. But if you want to use 1-inch labels to increase throughput, you don't want the printer talking to the tag before or after the one you're trying to encode." One solution is automatic calibration. "With a calibration feature, the printer head can move back and forth, so the chip doesn't have to be in the same place every time," explains Dan Williams, marketing manager, Avery Dennison Printer Systems (215-728-8054). "Because it can move back and forth, it can also jump over the chip, so it doesn't potentially damage the chip or wear the printer head." Error-processing and error-reporting are also considerations. Some printers can alert an operator, or another piece of equipment down the line, that a tag failed to write. "The reporting can get very sophisticated," says Schabacker of Datamax. "If a tag was partially written, the system can report what information exists on that tag. Or, to maintain the flow of product, it can tell a conveyor that the tag was bad and divert that carton to another area for retagging. The printer becomes an intelligent component of an overall system." The final consideration is the printer provider's ability to upgrade the system as new standards emerge. "You want to have a printer/encoder that's capable of doing what your current printer is doing in terms of throughput and programming functionality," says Svoboda of Sato America. "But you also want to make sure there's an upgrade path since everyone is awaiting the implementation of the Gen2 protocol." Applying tags For now, most companies are applying RFID tags and smart labels by hand until volumes ramp up enough to justify an automated solution. But several printer/applicators are available now. In RFID-land, applicators make sense in at least three scenarios. One is to reduce tag damage. "An applicator peels the liner away from the label without bending the chip and antenna," explains Tom Thatcher, president, Tharo Systems, Inc. (330-273-4408). "An operator, on the other hand, peels the label off the line, which means they'll bend the label as it's coming off." Another is if Wal-Mart or the Department of Defense represents enough of your business that you can create volume for the system. "An applicator makes sense where at least several hundred sequential boxes coming down the line need to have an RFID label on them," Thatcher says. "Otherwise, you're probably going to put them on by hand." The third scenario is if a company can move the application of the RFID tag back into the manufacturing process. "Applying the tag at the manufacturing line is where the cost will be the lowest," says Todd Warden, vice president of business development, MARKEM Corp. (603-352-1130). "That's because manufacturing is a highly controlled environment, with machines you rely on for high levels of data integrity." By applying the RFID tag in the manufacturing process, Warden adds, manufacturers can scan raw materials at the front end of the process and associate that information with lots, batches, products, cases and pallets for complete track and trace of that product. Along with applying tags, applicators have to contend with bad tags. One solution is to fast-forward a bad tag to a take-off roll. "That allows the bad tags to be accounted for," explains Brown of Lowry Computer Products. Dealing with bad tags also impacts the throughputs of these systems. "Throughputs depend on the length of the tags, but it also depends on the quality of the tags," says Ann Marie Phaneuf, director of marketing, Weber Marking Systems (847-364-8534). "Our equipment can apply from 20 to 40 cartons per minute. But if a system hits multiple bad tags in a row, you're going to slow down throughput." Phaneuf says end users will have to decide whether to hold a carton in place until a good tag can be encoded and applied. Or they can divert that carton to a rework area to maintain the line speed. End of the line When all is said and done and a tag or smart label is applied, that tag has to be verified as working once it's on a carton or pallet. This is typically going to involve a separate reader down the line from the print and apply station. "The issue is not whether the tag could be read when it came out of the printer, but whether it can still be read once it's on your product," says Fox of FOX IV. Since a good read can be affected by a multitude of things, Fox says Wal-Mart and other retailers need to develop a verification standard to test a tag once it's applied to a carton. "A bar code will work anywhere," says Fox. "That's not the case with RFID. You may verify your tag with a reader equipped with five antennas, but the readers at your customers' distribution centers may only have two antennas. And there are different specifications in Europe. We're going to have to come up with a standard way that everyone can verify their tags."
View All Blogs
