| 摘要 |
<p>The electronic cards respond to an interrogation signal (CALL) by emitting a response signal within a time slot (W0). After the interrogation signal the interrogation unit emits markers (M1, M2) of different types which are received and interpreted by the cards. Markers of the first type indicate the start of the time slot to the card, and of the second type cause the card to change state.</p> |
