Passive RFID for asset management

Until now, active RFID solutions have owned the asset management space. But passive RFID is poised to enter the market.

By Bob Trebilcock, Editor at Large -- Modern Materials Handling, 2/22/2007

Traditionally, the market for industrial RFID has consisted of two distinct camps.

Inexpensive passive tags, like the Gen II tags favored by Wal-Mart, were used for one-time, disposable applications.

Expensive active tags, with their own battery source and longer read ranges, were better suited for asset management applications, where the same tag might be used hundreds of times. That’s because an active tag uses power from the onboard battery to constantly transmit a signal that can be read by any reader in its range; a passive tag, on the other hand, has no battery and can’t transmit a signal until it’s interrogated by a reader.

“When you’re talking about real-time asset management and locating systems, you’re talking about active solutions because the tag is constantly transmitting a signal over a long range,” says Mike Liard, research director of RFID and contactless for ABI Research.

As the market for these solutions expands, however, new less-expensive passive solutions are in the works, according to Jerry McNerney, a senior director with Motorola Inc. (Note to readers: Motorola recently completed its acquisition of Symbol Technologies. Information about Motorola’s mobile computing and automated data collection solutions, including bar code and RFID technologies, can still be found at www.symbol.com)

“In the past, passive technology hadn’t matured enough to provide the read ranges, accuracy and read rates that active tags could provide in an industrial setting,” says McNerney. “But today, passive tags are coming to market that can operate in those environments at a much lower price.”

The solutions do operate differently.

In a yard management solution using active tags, for instance, active tags on trailers are constantly transmitting a signal to fixed readers located throughout the yard.

In a passive yard management solution, the yard jockeys used to shuttle trailers from a parking space to the dock are equipped with mobile readers. The readers interrogate passive tags on the trailers as the yard jockey travels up and down storage lanes.

“You do make some sacrifices, like read ranges,” says McNerney. “But when you take the price point into consideration, passive technology is becoming a compelling solution.”