Communications device for offering an electrical data signal as an acoustic/optical signal has a transmitter to make a link to a sender and transmit a message to the sender by using an electronic letter to detect the sender.

摘要

Data output devices (10-13) supply an acoustic/optical signal. A receiver device (8) connected in series to the data output devices receives an electronic letter from a sender and transmits this letter as an electronic data signal to the data output devices. A transmitter (9) makes a link to the sender and transmits a message to the sender. It also uses the electronic letter to detect the sender and selects the most suitable connection path to the sender.