A method for transmitting data by using a power line. The method includes: setting i=1 and j=1; receiving an i-th zero crossing signal at a time point ti, and determining, based on the i-th zero crossing signal, a start time when synchronization signals of a j-th data packet are transmitted, the start time when the synchronization signals of the j-th data packet are transmitted being t.sub.i+t; transmitting the synchronization signals of the j-th data packet at the start time when the synchronization signals of the j-th data packet are transmitted; transmitting data signals of the j-th data packet in sequence; and determining whether j is equal to M; when j is not equal to M, continuing a data transmission; and when j is equal to M, ending the data transmission, M being a number of data packets into which data to be transmitted is divided.

Systems, devices, and methods include a controller and a power unit coupled to a load device. The controller receives an altered AC signal, the altered AC signal comprising delays within an AC signal during a downward portion of a positive half cycle of the AC signal, determines a message from the delays within the altered AC signal, determines an action to execute based on the message, determines whether the delays present within a portion of the altered AC signal include a rising type delay, in response to determining the presence of the rising type delay in the altered AC signal, causes the power unit to introduce voltage within the altered AC signal transforming the portion of the altered AC signal including the rising type delay into a conditioned power signal, and transmits the altered AC signal or the conditioned power signal to the load device based on the action.

In one embodiment, a method includes transmitting pulse power on two wire pairs, the pulse power comprising a plurality of high voltage pulses with the high voltage pulses on the wire pairs offset between the wire pairs to provide continuous power, performing low voltage fault detection on each of the wire pairs between the high voltage pulses, and transmitting data on at least one of the wire pairs during transmittal of the high voltage pulses. Data transmittal is suspended during the low voltage fault detection.

Systems, methods, and processor readable media for distributing digital data and electrical power to a plurality of devices over high-impedance cables are disclosed. Certain embodiments include a gateway device connected to a power source, a first device connected to the gateway device by a cable, the cable being a high-impedance cable having at least two conductive paths, and wherein the first device receives electrical power and digital data from the gateway device via the cable over the same conductive path of the cable, a second device connected to the gateway device by the cable wherein the second device receives power and digital data from the gateway device via the cable over the same conductive path, and wherein the power source provides power to the first and second devices via the cable, and wherein the second device is connected to the gateway device through the first device via a daisy-chain topology.

An electrical meter (M) installed at a facility (F) supplied electrical power by a utility's (U) electrical distribution system (EDS) utilizes a two-way automatic communications system (TWACS) for receiving messages from the utility sent over the electrical distribution system using the TWACS. An improvement to the meter comprises reconfiguring existing components installed in the meter to function as an analog-to-digital (ADC) converter so to facilitate processing of powerline waveforms (WF) propagated through the electrical distribution system by application of a signal based detection algorithm. This improves detection of signal elements comprising a message sent via the TWACS and by other means and incorporated in the electrical waveforms thereby reducing occurrence of a false synchronization with the message elements so a content of a message is readily ascertained by the meter.

A component of an HVAC system includes a controller; a communications module in communication with the controller, the communications module including: a modulator/demodulator configured to encode and decode data in a modulated waveform on a communications interface.

In one embodiment, a method includes transmitting pulse power on two wire pairs, the pulse power comprising a plurality of high voltage pulses with the high voltage pulses on the wire pairs offset between the wire pairs to provide continuous power, performing low voltage fault detection on each of the wire pairs between the high voltage pulses, and transmitting data on at least one of the wire pairs during transmittal of the high voltage pulses. Data transmittal is suspended during the low voltage fault detection.

Techniques for computing electrical phase of electrical metering devices are described. In an example, data indicating zero-crossing times at first and second metering devices is obtained. A time-difference between the zero-crossing times may be determined. In a first example, the time-difference may be based at least in part on calculations involving a first value of a first free-run timer on a first metering device, a second value of a second free-run timer on a second metering device, and a time of a transmission between the metering devices. In a second example, the time-difference may be based at least in part on calculations involving a start or end time of a time-slot of a spread spectrum radio frequency transmission scheme. A phase difference between the first zero-crossing and the second zero-crossing may be determined, based at least in part on the determined time-difference.

An electrical meter (M) installed at a facility (F) supplied electrical power by a utility's (U) electrical distribution system (EDS) utilizes a two-way automatic communications system (TWACS) for receiving messages from the utility sent over the electrical distribution system using the TWACS. An improvement to the meter comprises reconfiguring existing components installed in the meter to function as an analog-to-digital (ADC) converter so to facilitate processing of powerline waveforms (WF) propagated through the electrical distribution system by application of a signal based detection algorithm. This improves detection of signal elements comprising a message sent via the TWACS and by other means and incorporated in the electrical waveforms thereby reducing occurrence of a false synchronization with the message elements so a content of a message is readily ascertained by the meter.

Disclosed are a power interruption method and a power interruption device based on a period measurement of an instantaneous power level. The present invention provides a power interruption method and a power interruption device which accurately determine, when a value measured by a current transformer (CT), a voltage detector, etc., is input into a main control unit, whether the measured value is a value equal to or more than a predetermined threshold during a digital analysis processing process to effectively protect a load which receives power by rapid and accurate power interruption for load-side instantaneous overcurrent or overcurrent caused by electric leakage/short-circuit.