A radio-frequency-identification (RFID) reader and an RFID tag exchange data using electromagnetic fields. Labels, clothes and plastic cards, among other items, can all include RFID tags.
The tags often include data that identifies the object, as well as its position and other details. It is the perfect technology for tracking items in stores and warehouses, since the reader can access the data from as far as 20 m away without any physical touch. Motorola used RFID technology as a way to track factory inventories, which was the initial use for it.
Also read: How to integrate RFID in any tracking application
In addition to these applications, RFID technology is utilized in air traffic control, toll collection, parking meters, petrol pumps, access control systems for buildings and rooms, and fare collection for public transportation. Monitoring high-value items and managing the supply chain are two other areas where RFID is used.
RFID tags can be either battery-powered or passive. As the name implies, battery-powered RFID tags use an internal battery as a power source, whereas passive RFID tags do not and instead rely on electromagnetic energy from an RFID reader.
Three basic frequencies—low frequency, high frequency and ultra high frequency—are used by passive RFID tags to convey information. RFID systems with a low frequency of operation range between 30 and 500 kHz. The transmission range of low-frequency RFID is relatively short, ranging from a few inches to less than 6 feet.
RFID systems with high frequencies range from 3 MHz to 30 MHz. The typical range is a few inches to many feet. Ultra-high-frequency RFID systems can typically be read from a distance of 25 feet or more and have frequencies ranging from 300 MHz to 960 MHz.
When a passive RFID tag is scanned by a reader, the scanner sends energy to the tag, enabling the chip and antenna to be powered and transmit data back to the reader. A tag, an antenna and an interrogator are the three essential components of an active RFID tag. An active RFID tag's battery should give enough power, but, if it dies, the device must be replaced because the batteries are not yet interchangeable.
Beacons and transponders are the two types of active RFID tags. Because an active RFID is always delivering a signal, it is a fantastic choice for anyone looking for real-time tracking. They are expensive instruments, but they have a large read range, which may be beneficial depending on the application.
The cost of using passive RFID tags is much lower. They are therefore a common option for applications such as access control, file management, supply-chain management and race tracking. Comparatively speaking, a passive RFID tag's read range is much smaller than an active RFID tag's read range.
RFID is becoming more common as a barcode substitute. Both barcodes and RFID are used to track inventory, albeit there are some differences between the two. Here are a few important differences between RFID and barcodes. RFID identifies goods without requiring a direct line of sight, unlike barcodes, which do. RFID can scan from inches to feet, whereas barcodes must scan at close ranges. RFID requires electricity, but barcodes do not. RFID data is always up to date, whereas barcode data is read-only and cannot be changed.
RFID has several drawbacks, notably collisions and expense. Reader collision occurs when a signal from one RFID reader interferes with a signal from another. This can be avoided using an anti-collision method. RFID tags will be required to broadcast to their respective readers as part of the protocol.
Tag collision is another prevalent problem, which occurs when many tags submit data to an RFID reader at the same time. This issue may be avoided by employing a reader that collects data one tag at a time.
RFID has many downsides, including security and technical concerns. Because RFID tags cannot discriminate between numerous readers, when data is transferred, it can be received by anybody. This is especially problematic because RFID readers are portable, and certain RFID tags have a long range, making it easier for unauthorized parties to obtain the data.
Another barrier for RFID systems is the expense, which is related to the system being time-consuming and labor-heavy. Companies spend a significant amount of time evaluating a wide range of hardware and systems in order to discover the greatest fit for their needs. These problems are frequently mitigated when using barcodes, which is why they remain a popular data-collection and inventory-control option for many organizations.
About the author: Shawn Cox
Shawn Cox is a licensed master electrician/PLC programmer. He was co-owner/operator of Bobby Cox Electric for 15 years and is currently employed by BMW Manufacturing as an ESA. Contact him at [email protected].
