Patent ID: 8150316

Claim:
A circuit which includes a communication partner appliance that is designed for contact less communication and as a data carrier with at least one further communication partner appliance, the circuit comprising: activators to activate a first communication mode or a second communication mode of the communication partner appliance; a receiver to receive a carrier signal that is transmitted to the communication partner appliance by the at least one further communication partner appliance; a detector coupled to the receiver, wherein the detector is configured to detect the presence of the received carrier signal and to transmit within the circuit of the communication partner appliance a carrier signal present signal in the event that the carrier signal is present, and otherwise to transmit within the circuit of the communication partner appliance a carrier signal not-present signal as a consequence of a missing carrier signal; and a processor coupled to the detector and the activators, wherein the processor is configured to: recognize a command signal transmitted to the communication partner appliance with the carrier signal; generate and transmit within the circuit of the communication partner appliance a command-end signal that is separate from the transmitted command signal and represents the end of the transmitted command signal; determine whether, after the occurrence of the command-end signal, the carrier signal present signal is present; and transmit a first activation signal to the activators when the carrier signal present signal is present to bring the circuit into the first communication mode, and otherwise transmit a second activation signal to the activators to bring the circuit into the second communication mode.