RFID on the Production Line
nt technological advances have reduced RFID tags to almost semiconductor chip-sized, which is small enough to be inserted into barcodes, other labels, or directly into products. They're usually attached to increasingly smaller cases and packages, and are meant to be disposable, which is referred to as an 'open-loop' application.

Despite these advances, passive RFID tags typically cost 35-45 cents in large quantities, 75-80 cents in small quantities, or up to 85 cents and more for active RFID t

ags with more reading, writing, data storage, range, and other performance capabilities. Unfortunately, this remains higher than the 5-10-cent threshold that RFID tags reportedly would have to achieve to make them economically viable in most mainstream, disposable, open-loop applications.

Passive tags are powered by the small amount of RF energy that excites them when they enter the electromagnetic field surrounding the RFID system's antenna or reader. For example, 13.56 Mhz tags allow readings at up to 1 m. Once the tag is charged, the reader can interact with it, and pass the tag's data to a linked controller, PLC, PC, or on up to higher-level enterprise systems.

Interference, security, robustness

Similar to any wireless technology, RFID is subject to interference, usually when close to metals and liquids. Physical hurdles typically require more capable and costly tags, readers, or other customized methods.

Simple distance and physical read-write limits usually prevent unauthorized access to tag data, while new RFID Gen 2 standards under development by the EPCglobal organization are expected to address some of these ongoing concerns. Gen 1 is a published EPCglobal standard that is already being used by many RFID developers.

Impinj reports that it recently launched a fully integrated RFID Gen 2 system that includes its fully compliant Gen 2 chips, tags, labels, inlays, and readers.

'Barcodes are the cheapest way to tell what a part is and where it's going, but there are ma