RFID (Radio Frequency IDentification) is an electronic method of exchanging data over radio frequency waves. There are three major components to a RFID system: Transponder (Tag), Antenna and a Controller.

The Transponder (Electronic Transmitter/Responder) contains a silicon microchip, smaller than a grain of rice, and a small antenna. Some Transponders have integrated batteries for powering the chip. These are called "Active Tags" while "Passive Tags" are powered by the Radio Frequency waves and do not require batteries.

Typical RFID System

Tags come in a variety of shapes and sizes. Tags can be attached to various objects. These objects include products, cartons, totes, pallets, parts, assemblies in manufacturing, cars, trucks, physical assets, etc. Tags are sold in various types. These include adhesive back labels, credit card shaped laminate, screw down plastic assemblies and a host of other types of tags.

The Antenna is a device that either reads data from tags or, in some cases, writes data to tags using radio Frequency waves. Antenna's come in all shapes and sizes depending on the environment or the required range. Antennas can be mounted on the floor, to sides of conveyors, on lift trucks, or on building structures.

The Controller (Interrogator) is the electronic device that receives the data from the antenna, or transmits data to the antenna, and usually communicates this data to a host computer or PLC. The controller manages the information between the RFID products and the Host system. Some controllers are equipped with programmable I/O points that can be used to make local decisions.

USES FOR RFID
Most of us have seen RFID technology in use but may not recognize it. Most toll booths today offer a prepaid pass that allows the driver to simply drive through the toll booth without stopping. These cars are equipped with a Tag that emits unique RF waves that identify the vehicle and cause the drivers prepaid account to be automatically debited.

For many years RFID technology has been used for tracking livestock on farms. Tags are installed either on or under the skin of animals. These tags store information about the animal such as its identification number, its medical history, and its weight and age. Being able to identify the needs of an animal during feeding and medical attention without having to look up the animals history in printed logs saves the farm considerable time and money.

Some airports currently use RFID technology to track and sort baggage in the terminal. This allows for a completely automated baggage handling facility.

RFID's current uses include material handling, logistics, warehousing, manufacturing, personal identification and many more applications. Simply put, applications are limited only by your imagination.

ADVANTAGES OF RFID
RFID technology is frequently compared to Barcode technology. While RFID technology will probably never replace Barcode technology, it does have many advantages. The following is a list of a few of these advantages:

• You must have 'Line of Sight" to read a barcode label.

• RFID tags can be placed inside containers or on surfaces that are not in the line of
   sight from the antenna.

• RFID technology has a longer read range compared to Barcode Technology.

• Considerably more data can be stored on RFID tags than on a Barcode label.

• You cannot write to a barcode label whereas some RFID tags have Read/Write capablilites.

In many applications, both Barcodes and RFID transponders are incorporated into labels. There are manufacturers who supply barcode label printers that have Transponders built into the label. The labels are both printed and programmed with the identification number.