Basics on Radio Frequency Identification (RFID)
Posted: Sunday, Feb. 21, 2010 by Roger ThomasRFID is one of the most commonly used forms of Automatic Identification & Data Capture (AIDC) technology and forms the foundation of many asset management solutions, so let’s take a closer look at this particular technology. RFID utilizes radio waves to identify and track assets as they move from place to place. Whether used alone or in conjunction with other AIDC technologies, such as bar code or GPS, RFID can reveal valuable information about the inner workings of supply chains.
In a typical RFID implementation, electronic devices referred to as RFID tags are affixed to or incorporated into an asset or product that needs to be tracked. When the tag and its associated asset come within range of an RFID reader, data stored in the tag is collected by the reader, passed up through various software platforms and presented to users. Information stored on an RFID tag can include an asset identification number, sensor data and information on the asset’s history. This information helps users cut costs through more efficient management of their assets.
RFID technology is mainly available in two forms: active and passive. The table below outlines how active and passive RFID devices stack up.
| Active RFID | Passive RFID | |
| Tag Power Source | Internal to tag | Energy transferred using RF from reader |
| Tag Battery | Yes | No |
| Availability of Power | Continuous | Only in field of reader |
| Required Signal Strength to Tag | Very low | Very high |
| Range | Up to 100 meters | Up to 3–5 meters, usually less |
| Multi-tag Reading | 1000s of tags recognized — up to 100 meters | Few hundred tags within 3 meters of reader |
| Memory | Up to 128 kilobytes of read/write with sophisticated search and access | Up to 128 bytes of read/write |
| Price | Low-end active tags may cost as little as $10, while premium active tags can cost several hundred dollars | Passive tags vary in price from 10¢ to about $5 |
