| 摘要 |
Even when a plurality of cards have entered an communication area, the cards within the communication area may be accessible, and, if a data collision occurs, the order of accessing to the cards is expeditiously determined to perform an efficient communication. Each card determines a timing for returning a response block containing an ID code based on conditions directed by a read/write device and the ID code of its own. The read/write device is caused to receive the response block returned by the contactless IC card and to detect a data collision. Based on this result, the conditions are changed so that a respective response block containing an ID code is returned again, thereby concurrently processing the plurality of contactless IC cards. <IMAGE> |
