Apparatus for addressably controlling remote units

Abstract

A load management system which includes a central message generator and a plurality of addressable remote load controllers which selectively connect and disconnect high power deferrable loads to and from a power source in response to transmitted messages. The load controllers include means for translating coded tone pair inputs into digital data. Tones selected from three such tone pairs are used in one scheme, where a tone selected from the first tone pair is used for the initial bit of a message, and subsequent tones are alternately selected from the remaining two tone pairs or the remaining bits. One of the tones of the first tone pair is utilized as a test tone which initiates a test routine sequence. The test tone can be transmitted by a portable, low power transmitter to test the functioning of the remote units. A message format includes two code sets, a zone code set and a command/address code set. Each load controller has a preprogrammed zone identifier and a preprogrammed address identifier, and is responsive to a command/address code message only when the last received zone code message has identified the preprogrammed zone identifier of that load controller and the command/address message indicates the preprogrammed address identifier of that load controller. All load controllers having a common zone identifier are responsive to a scram instruction message which identifies that zone.