Patent ID: 8325046

Claim:
A radio frequency identification (RFID) system, comprising: a plurality of RFID a tags, each having a tag antenna and a tag circuit that stores identification information; and a reader-writer including a first transceiver that reads the identification information of the plurality of RFID tags using an antenna, wherein, when the identification information is not read from one of the plurality of RFID tags due to an occurrence of a reading error in the first transceiver after a reading command for reading the identification information is transmitted from the first transceiver via the antenna, the reader-writer adds reading error information, which indicates the occurrence of the reading error, to a next reading command to be transmitted, and transmits the next reading command from the first transceiver via the antenna, and wherein each of the plurality of RFID tag includes: a reading error detector that analyzes the reading error information added to the reading command to determine whether the reading error occurs; a reading-completion flag that indicates information on whether the identification information is completely read by the reader-writer; and a controller that sets the reading-completion flag based on a determination result of the reading error detector.