Gotcha!: Frequent Radio Frequency ObstaclesBy David F. Carr | Posted 2005-02-01 Email Print
Radio Frequency Identification still faces static.
Broad adoption of Radio Frequency Identification technology by distributors and retailers of consumer goods continues to inch forward, spurred by new standards such as the 28-digit Electronic Product Code. This breaks through the limits of the near-ubiquitous 12-digit Universal Product Code bar code, which stores manufacturer and product information. The added room allows for serial numbers that companies can use to track and trace individual items as they wend their way from factory to store. But those digits still have to deal with fundamental problems radio waves encounter when reading microcircuit tags on packages and pallets.
Problem: Metals and fluids can interfere with radio signals.
Resolution: Extensively prototype any equipment that will read tags on packages that include metal or contain liquids. If there is interference, determine the cause. Find out if a metal or fluid is impeding the transmission of radio waves, and be ready to move the tag or reader to a more suitable spot.
Sometimes the fix can be simple, such as moving a tag from the side of a bottle to the cap. But keep track of your testing. "The way you build your proof of concept is key," says Sam Brooks, vice president of InLogic, a consultancy in Kennesaw, Ga.
With enough experimentation, RFID will work on virtually any product, he says. But there's always an exception. Brooks remembers one trial involving a foil-lined box of Cascade powdered dishwasher detergent. No matter what InLogic tried, it could not get a read off a radio tag affixed to the box.
Problem: Tag quality is uneven.
Resolution: Test all tags before attaching them to a product or pallet. Some buyers report receiving shipments where 10% to 15% of the tags were defective. The only way to make sure 100% of your tags work is to test 100% of the tags, using actual signals from a working RFID reader. This will be necessary until tag quality improves and reliability is unquestionable.
Problem: Affixing tags may slow down manufacturing.
Resolution: Carefully choose where you begin to use tags. Why? It may only be possible to put tags on 30 cases of product per minute. If your production line had been churning out 100 cases of product before this, the tagging becomes a bottleneck, according to R4 Global Solutions, a consultancy in San Francisco.
For pilots and initial implementations, consider products that are relatively high value and low volume. What's impractical for cases of cigarettes might be reasonable for cases of hand-rolled cigars.
Problem: Costs may be too high to use the new Electronic Product Codes in radio tags.
Resolution: Consider other means of deploying EPC codes. For instance, a supplier could print EPC codeswhich look like typical bar codes but hold more informationon its products. EPC codes can be read by existing bar-code systems. The supplier also could print numbers on its packages that represent the EPC information. Those numbers could then be punched into a partner's computer systems, much as a cashier does when a register fails to read a conventional bar code.
Printing EPC code on products also provides a backup should a radio system fail, notes Ross Stapleton-Gray, a principal with Stapleton-Gray & Associates in Berkeley, Calif.