The combination of supervisory control with other functions on power-line carrier channels

THE PRACTICE of using a single power-line carrier channel to perform several different functions is becoming increasingly common. This practice is encouraged by the savings in equipment and in carrier-channel space that can be effected when a single carrier transmitter and receiver are used jointly by some combination of relaying, telemetering, communication, load control, and supervisory-control equipment. The recent introduction of a wide line of individual rack-mounted carrier components¹ makes it possible to select exactly the apparatus necessary for the combination of functions to be performed and further encourages the use of a single carrier assembly for several co-ordinated functions.