Continuing to the RFID question vessel, and the RFID question vessel

摘要

PROBLEM TO BE SOLVED: To autonomously avoid interference between a reader/writer and an electronic tag.;SOLUTION: The reader/writer judges, after starting command transmission to the IC tag, interference detection between the reader/writer and an IC tag when an IC tag nonresponse ratio in second timeout time Tcheck time at the last of the timeout time Tto is larger than a second fixed value when a ratio that the IC tag becomes nonresponse to a command in the timeout time Tto is larger than a first fixed value. When the interference is detected, command transmission to the IC tag is stopped by transmission stop time Tsleep and performs carrier sense again after the elapse of the transmission stop time Tsleep. Interference detection processing is repeated in timeout judgment continuation time Tct from the starting of the command transmission and a reader/writer which does not become timeout in the timeout judgment continuation time Tct continuously perform communication to the maximum continuous transmissison time T₁ as the upper limit.;COPYRIGHT: (C)2008,JPO&INPIT