RFID FAQ

RFID System FAQ

What is RFID system?

RFID system is a non-contact ID system which can read and write data on a tag via radio waves or electromagnetic waves. It consists of a tag (data carrier, ID card) which stores data, an antenna which communicates with the tag, a controller which controls the antenna, and higher-level equipment (system) which controls the controller. Communication methods between the tag and the antenna include a microwave type using radio waves, and an electromagnetic inductive coupling type applying the electromagnetic principle (transformer principle).

How does an RFID system work?

An RFID system consists of a tag, which is made up of a microchip with an antenna, and an interrogator or reader with an antenna. The reader sends out electromagnetic waves. The tag antenna is tuned to receive these waves. A passive RFID tag draws power from field created by the reader and uses it to power the microchip’s circuits. The chip then modulates the waves that the tag sends back to the reader and the reader converts the new waves into digital data.

What is reader collision?

One problem encountered with RFID is the signal from one reader can interfere with the signal from another where coverage overlaps. This is called reader collision. One way to avoid the problem is to use a technique called time division multiple access, or TDMA. In simple terms, the readers are instructed to read at different times, rather than both trying to read at the same time. This ensures that they don't interfere with each other. But it means any RFID tag in an area where two readers overlap will be read twice. So the system has to be set up so that if one reader reads a tag another reader does not read it again.

How much does a fully functional RFID system cost?

The cost depends on the application, the size of the installation, the type of system and many other factors, so it is not possible to give a ballpark figure. In addition to tag and reader costs, companies might to purchase middleware to filter RFID data. They will likely need to hire a systems integrator and upgrade enterprise applications, such as warehouse management systems. They might also need to upgrade networks within facilities. And they will need to pay for the installation of the readers. Not only do the readers need to be mounted, they need electrical power and to be connected to a corporate network. All of these factors are different for each deployment, depending on the application, the environment and so on.