Distance Encoder Automates RFID Tag Writing

By Claire Swedberg

RF Controls has built a new functionality into its overhead reader antennas to encode UHF RFID tags, or to change their EPC IDs, from up to 50 feet away.

May 30, 2023Writing to radio frequency identification (RFID) tags usually requires close proximity between a tag and an encoding or writing device (often a handheld reader), and the tag typically needs to remain still during that process. In comparison with reading a passive UHF tag, which can be accomplished in bulk, at a distance and in motion, the process of encoding one or updating its Electronic Product Code (EPC) can be time-consuming. That limits some RFID applications in which users need to commission or decommission tags in a hurry or in large batches.

Passive real-time location system (RTLS) company RF Controls has built a solution that it released this spring as a software upgrade to its existing overhead RFID reader antennas. With the new distance RFID encoder functionality, the overhead reader antennas can isolate and then write to a tag from the distance of a high ceiling. The solution enables manufacturers or other companies tracking goods via RFID to change a tag's EPC ID, or to encode the tag for the first time, automatically.

The distance-encoding feature relies on the company's steerable phased-array technology and updated software to pinpoint a specific tag's location for encoding, even at a distance.

The new feature earned the company a finalist spot for Best New Product in this year's RFID Journal Awards, which was presented at RFID Journal LIVE! 2023. The system is now being tested in early deployments by a military agency, as well as by manufacturers and logistics providers, and it is intended to solve a problem with existing technology, according to Zak Dingsdale, RF Controls' VP of marketing and corporate finance. Traditionally, a reader must isolate a particular tag within a group to ensure it properly receives the data. This requires either a worker using a handheld reader directly in front of a tag, or a desktop reader or printer, all of which can be time-consuming.

For RFID printers, Dingsdale explains, commissioning tags at a manufacturing facility, which could have a high metal presence, can be difficult or impossible. "RFID printers certainly have their place with commissioning tags in many environments," he says, "but certainly not all environments." Instead, RF Controls' encoding function is intended to provide automation, even in metallic, industrial environments. The functionality was designed for use with the company's CS Smart Antenna bidirectional devices—either the CS-490 or CS-445B RTLS model (see Best New RFID Products of 2020: RF Controls' CS-490 Smart Antenna and Times-7's Packing Station).

The company's wide-area passive RFID RTLS solutions and dock doors are already being used at warehouses and factories to provide real-time location data. Both antennas had encoding functionality built in, but the latest software makes the distance greater, at a higher speed. The distance-encoding feature relies on the company's steerable phased-array technology and updated software to pinpoint a specific tag's location for encoding, even at a distance.

To encode or write to tags with the overhead antennas, individuals can employ their RFID software to select specific tag IDs, including their serialized transponder IDs (TIDs), and to determine which tags need to be changed or encoded. Once a particular tag ID is selected, the reader will seek that specific tag as items pass within range, such as on forklifts moving into or out of a dock door, or into and out of specific zones. Alex Gaddie, an RF Controls software developer, says the antenna uses its new software to find and then "lock" its beam onto a specific tag, and to follow it as it moves.

RF Controls' encoding function is intended to provide automation, even in metallic, industrial environments.

Once locked in on the tag, Gaddie explains, the antenna transmits a highly focused RF beam with the encoding instructions. That can mean writing a specific EPC code to a new tag, or it can involve changing one or more digits of the tag's existing EPC number, thereby creating what is functionally a new tag, or a decommissioned tag. In the future, he says, the antenna will be able to manage batches of tag changes. In that case, an individual could seek to change the EPC numbers for a set of tags—based on a given category, for instance—and those tags would then each have a new ID.

Some companies are using the distance-encoding feature to commission new tags that have not yet been encoded. They would apply a new RFID tag to a box, pallet or bin that has no EPC encoded on it, then instruct the software to automatically encode them, without requiring any additional manual effort. Alternatively, companies can change the tag's ID number, and the item to which it is applied, to have a new identity. For instance, if a reusable tote has been emptied of its contents and is slated to be reused to transport other materials or supplies, the new tag ID would create a different identity for the next transit journey.

Companies now testing the new feature include several manufacturers, RF Controls reports. If users wish to change a tag's ID, they can instruct the software to alter a single digit within the EPC number. One example might involve changing the status of a product being assembled. Two separate components could be tracked with an RFID tag, each with its own unique ID.

Once those two components are fitted together, they become a single combined component (such as two pieces of pipe that create a joint). The antennas could then switch a digit in the two tags' EPC numbers, thus creating a new number that would represent the single component. Sales personnel could use the re-encoded data to track customer orders in real time, simply by logging into a company's enterprise resource planning systems and checking the current EPC value for the order.

Zak Dingsdale

For logistics, businesses can utilize the system to track reusable bins and totes. Traditionally, some companies have been applying a new RFID tag to a bin every time it is used for a new shipment. In this scenario, however, users could simply set the software to update a single tag for each journey. Once the digit is changed, the number is updated in the software, and the bin begins another journey as though it were a new container. In that way, companies can differentiate each shipment with one container, as well as monitor how many times that container has been used, and thus when it needs to be removed from the supply chain.

In addition, military agencies are testing the technology to decommission a tag (or zero it out) by switching the EPC number to zeros, thereby making it no longer operable. In that way, the system can update the status of a particular piece of equipment or vehicle to which a tag is attached, as being out of commission. In the future, the technology could update a tag's user memory, though it is currently designed only to update EPC numbers.

The goal, Dingsdale says, is to reduce the incidence of bottlenecks in systems that had previously required a close-range connection between an encoder and a tag. The distance encoder is poised to make parts, materials and products move through the various stages of production and transportation more quickly, he states, adding, "The potential applications are broad across the many sectors of the global economy."