| 摘要 |
PROBLEM TO BE SOLVED: To efficiently shorten processing time by efficiently detecting plural radio cards. SOLUTION: When a polling command with ID specified in the number of times of automatic retry (one time) is issued from a host device 1, first of all, a reader/writer 3 issues a polling command with ID (ID number = 00h), receives a response from the radio card, which enters a communication enable area, and automatically issues the received polling command with ID (IDm1) once more this time. Since a radio card (IDm1) 5 is an ID (IDm1) designated by this polling command, a response from the other radio card 5 is received and the received responses of ID (IDm1, IDm2 and IDm3) or radio cards 5... are returned to the host device 1. |
