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ISO/IEC 15693, is an ISO standard for ''vicinity cards'', i.e. cards which can be read from a greater distance as compared to proximity cards. ISO/IEC 15693 systems operate at the 13.56 MHz frequency, and offer maximum read distance of 1–1.5 meters. As the vicinity cards have to operate at a greater distance, the necessary magnetic field is less (0.15 to 5 A/m) than that for a proximity card (1.5 to 7.5 A/m). == Communication to the card == Communication from the reader to the card uses an amplitude-shift keying with 10% or 100% modulation index. The data coding is: ;1 out of 4 pulse position modulation : 2 bits are coded as the position of a 9.44 µs pause in a 75.52 µs symbol time, giving a bit rate of 26.48 kilobits per second The least-significant bits are sent first. ;1 out of 256 pulse position modulation : 8 bits are coded as the position of a 9.44 µs pause in a 4.833 ms symbol time, giving a bit rate of 1.65 kbit/s. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「ISO/IEC 15693」の詳細全文を読む スポンサード リンク
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