| 摘要 |
In a data carrier (2) which is provided as a communication partner appliance for a communication system with at least one further communication partner appliance (3, 40), a first communication mode or a second communication mode can be activated. A detection device (32) for detecting the presence of a received carrier signal (RS) transmits a carrier signal present signal (PS) in the event of a carrier signal (RS) being present, and otherwise a carrier signal not-present signal (NPS). A command signal that can be transmitted with the aid of the carrier signal (RS) triggers a determination stage (27) for determining whether after the end of the command signal has occurred, at a given measurement point in time, the carrier signal present signal (PS) is present. If the carrier signal present signal (PS) is present, the data carrier (2) is brought into the first communication mode with the aid of activators (30, 35); otherwise, it is brought into the second communication mode. |
