Abstract: An arrangement for transferring both power and information on one or more common AC power lines in which a first type of information is transmitted by terminating the current from the power supply in periods which constitute a fraction of a halfwave cycle. The transmission of this first type of information is dependent upon the frequency of the AC power supply. A second type of information is transmitted during the periods in which the current from the power supply is terminated, and the second type of information is transmitted at a higher frequency independent of that of the AC power supply.