Abstract: The network comprises a master node and a plurality of slave nodes. To configure the network, the master node transmits over the network a hailing message at any attenuated level compared to normal communication signals to be transmitted over the network. Upon receiving the hailing message at one of the slave node, a reply message is transmitted, also at an attenuated level. Receiving the reply message at the master node allows it to configure the slave node from which the reply message originated. Also disclosed are a method of managing a network so as to monitor the connections between the slave nodes, and a method of managing a network when a recovery operation is required.

Abstract: The power line communication system includes a transmitter and a receiver, both providing a communication path between two communication control devices over a power line. The transmitter includes a voltage amplifier and a current amplifier. A switch between the transmit and receive modes is implemented within the voltage amplifier. The current amplifier also has a two-step output impedance. When the transmitter is active, the current amplifier shows a low impedance on the line to overcome other loads. If, however, the communication medium shows a high level of noise, the output impedance of the current amplifier decreases even further and creates a path to ground. The receiver advantageously uses a logarithmic amplifier for signal range compression. This type of amplifier preserves the shape of the signal that is important when the modulation scheme uses the zero crossings to store information.

Abstract: The present invention relates to a system for centralized controlling of a plurality of temperature regulating devices by an existing network of power lines comprising a central control means provided to send or receive predetermined commands to and from a plurality of temperature regulating devices. Each of those devices comprises a communication means adapted to provide two way communication with the central control means, a microprocessor means adapted to store predetermined information received from the central control means, a temperature sensor means adapted to send signals to the microprocessor means and an output means adapted to supply power to temperature varying units. The system further includes a network protecting means adapted to regulate the supply of power to output supply means during sudden change in power supply or due to changes in temperature conditions and a locking means adapted to prevent an unauthorized entry to change temperature condition.