How RFID Systems Work

RFID is similar concept to bar coding. Bar systems use a reader and coded labels that are attahed to an item, where as RFID uses a reader and special RFID devices that attached to an item. Bar codes use optical signals to transfer information from the label to the reader RFID uses RF signals to transfer information from the RFID device to the reader.

Radio waves transfer data between an item to which a RFID device is attached and an RFID reader. the device can contain data about the item, such as what the item is, what time the device travelled through a certain zone, perhaps even an parameter such as temperature. RFID devices, such as a tag or label, can be attached to virtually anything, from a vehicle, to a pallet of merchandise.

The reader and tag communication using the antennas and a defined command set. The communication protocol is defined such that the reader first sends a command and the tag responds. The command set includes commands to read and write data, to control the anti-collion protocol, to lock individual memory cells, and teh deactivate the tag.