What is RFID?

Radio Frequency Identification (RFID) is a generic term for technologies that use electromagnetic field or radio waves to automatically identify people and objects. Wireless communication takes place between a reader (sometimes interrogator) and a small transponder called tag.

RFID is a technology often seen as a descendant of the ubiquitous barcode, which has been used since the late 1960's as a printed means of identifying product categories. Unlike barcodes, no clear line of sight is required to obtain an accurate read. There are different versions of barcode technology (EAN, JAN) encompassing 8 to 14 digit systems and same coding schemes can be combined for RFID.

The basic RFID system comprises a tran­sponder, a reader and an antenna. Data is stored in a tag. Current tags, depending on applica­tion, can hold up to 64 kilobits of data. Tags can be read-only, one time programmable or read/write.

A radio frequency signal is transmitted from the reader to a transponder that passes within range of the reader's antenna. The signal triggers RF emissions from the tag. The transponder holds bits of data, which is either reflected or sent back to the reader, depending on whether the tag is passive or active. Transponder data includes information such as the transaction record type, the unique transponder ID number, the reader ID number, the transaction status code, and the error detection code. Customer data can be specified as well.

Glossary