IC card reader/writer, identification method and program

摘要

This invention provides a reader/writer, ID method and program comprising a response-detection unit of detecting normal responses and collisions from IC cards in response to a request; and a response-invalidation unit of sending a response-invalidation command, which is a command not to respond to requests in the future, to IC cards that sent normal responses when the response-detection unit received normal responses from IC cards even though collisions were detected.