Abstract: A remote-readable identification tag (T) that is provided with at least two resonance circuits (81 . . . 8n) and at least one transmitter/receiver antenna system (1) coupled with the circuits. The at least two circuits have a respectively different resonant frequency. A delay device (6) of the remote-readable identification tag delays a signal response between a signal received by the antenna system and a signal emitted in response by the antenna system, e.g., by delaying feeding the received signal into the resonance circuits.

Abstract: A remote-readable identification tag (T) that is provided with at least two resonance circuits (81 . . . 8n) and at least one transmitter/receiver antenna system (1) coupled with the circuits. The at least two circuits have a respectively different resonant frequency. A delay device (6) of the remote-readable identification tag delays a signal response between a signal received by the antenna system and a signal emitted in response by the antenna system, e.g., by delaying feeding the received signal into the resonance circuits.

Abstract: An active electrical-optical rear wall for connection of electronic devices to be brought into communication with one another, in plug-in technology, whereby optoelectronic terminal installations for respective connection of an electronic device are arranged on the rear wall, which installations are connected, by means of unguided beam connections, with optical transmission channels that connect adjacent terminal installations with one another, whereby each terminal installation respectively comprises one optoelectrical transmission and reception unit per transmission channel, which unit can be connected, by means of an optical unguided beam connection, with an optoelectrical transmission and reception unit of an electronic device that is to be connected to this terminal installation. The transmission channels form a bus whose operation is completely independent of whether electronic devices are connected to terminal installations or not.