Abstract: The present invention, in one embodiment, is a method for operating an electronic electric meter having current and voltage sensors configured to generate measurements of current and voltage, respectively; a microcomputer coupled to the current and voltage sensors and having on-chip masked read only memory (ROM); and a nonvolatile, alterable memory coupled to the microcomputer. The method includes steps of: storing vectors pointing to program portions of the ROM in the non-volatile memory; and using the stored vectors to operate the microcomputer to execute the program portions stored in the ROM to control operation of the meter.

Abstract: The present invention, in one embodiment, is a method for metering energy consumption with an electric meter. The method includes steps of: generating metering quantities for a plurality of phase voltages from a multiphase voltage source, including generating revenue-related data; monitoring voltage changes on at least one of the phase voltages; and performing a predetermined task in response to a voltage change on at least one of the phase voltages while continuing to generate revenue-related data.

Abstract: A method and apparatus for executing a command in a number of electrical metering devices of a power distribution system provides each metering device with a command having a predetermined execution time and subsequently executes the command in each of the metering devices once the present time value equals or exceeds the predetermined execution time. Each electrical metering device includes a clock for providing the present time value as well as a memory device for receiving and storing the command. Each electrical metering device also includes at least one controller or microprocessor for monitoring or comparing the present time value with the predetermined execution time of the stored command and for executing the stored command once the present time value is at least as large as the predetermined execution time. A command may thus be provided to each electrical metering device of a power distribution system at various prior arbitrary times.

Abstract: A demand electronic electricity meter having load profile recording capabilities is presented. Load profile recording requires memory for storing the recorded information, whereby either on-board memory or external memory is required. Load profile parameters include the number of channels (e.g., 1, 2 or more channels), interval size (e.g., 1, 5, 10, 15, 30 or 60 minutes), quantities to be recorded (e.g., kWh and kvarh, kVAh, or Qh) and channel scalar/divisor (e.g., for each channel, a 2 byte divisor and a 2 byte scalar). With two channels, only two quantities are available for recording, kWh and the one other quantity that the meter has been configured to record, (e.g., kvarh, KVAh, or kQh). For each quantity selected, snapshots of the corresponding total accumulator; (i.e. total kWh and total kvarh, kVAh or kQh) are automatically maintained.

Abstract: Line voltage and line current signals are sensed on a power line having at least one conducting path. The sensed line voltages and line currents are converted into a digital signal. A phase-to-neutral voltage signal and phase current signal are computed from the digital signal to thereby define a phase of the power line. An interval of orthogonality is determined from the sensed voltage and current signals, coinciding with passage of an integral number of cycles of a fundamental frequency reference signal which is computed from the computed phase-to-neutral voltage signal. A vector metering quantity is computed for the determined interval of orthogonality from the computed phase-to-neutral voltage signal and the computed phase current signal. The vector metering quantities to be computed may be identified and computed based upon an associated detent. The vector metering quantity is also computed based on an identified circuit topology.

Abstract: An electronic energy meter is described. The meter includes, in one form, voltage and current sensors having their outputs coupled to an analog to digital converter. The digital signals output by the converter are supplied to a digital signal processor (DSP) which outputs digitized metering quantities to a microcomputer. Using the metering quantities supplied by the DSP, the microcomputer performs additional metering calculations and functions. In one aspect, the present invention is directed to a method for determining whether an option board is being used and, if so, controlling meter operations in accordance with the coupled option board.In another aspect, the present invention is directed to a high function option board which, when enabled, operates as a master and the meter microcomputer automatically switches from its normal master mode to slave mode.

Abstract: Line voltage and line current signals are sensed on a power line having at least one conducting path. The sensed line voltages and line currents are converted into a digital signal. A phase-to-neutral voltage signal and phase current signal are computed from the digital signal to thereby define a phase of the power line. An interval of orthogonality is determined from the sensed voltage and current signals, coinciding with passage of an integral number of cycles of a fundamental frequency reference signal which is computed from the computed phase-to-neutral voltage signal. A vector metering quantity is computed for the determined interval of orthogonality from the computed phase-to-neutral voltage signal and the computed phase current signal. The vector metering quantities to be computed may be identified and computed based upon an associated detent. The vector metering quantity is also computed based on an identified circuit topology.

Abstract: A method of processing binary characters received by an electrical energy meter includes the step of generating a clock signal internal to the meter so that asynchronously received serial data can be processed, even though a synchronization clock signal does not accompany the serial data. The method includes the steps of detecting receipt of a first of a string of binary input characters at a serial input/output port of the meter, and then sampling the detected first character by generating a respective first clock signal which is phase-synchronized with a least significant bit of the first character. These steps are then repeated in sequence for each subsequently received character in the string. The sampled characters can be temporarily stored in meter hardware such as a register and written to memory such as programmable read-only or random-access memory.

Abstract: The method and apparatus for sharing passwords includes an electronic meter comprising a metering unit, a register unit, an optical port, and a communications unit. An external reading device, such as a handheld reading device or a personal computer, is coupled to the communication board via the optical port. The method and apparatus for sharing passwords provides that both the meter register and the communications unit have the same security code. In addition, the communications unit is able to distinguish between a security code for the communications unit and a security code for the meter register, and the communications unit will not interfere with communications between the external reading device and the meter register.

Abstract: An energy meter capable of converting from one mode of operation to another mode of operation is described. In the one embodiment, the present apparatus measures energy consumption, and converts operation from a first mode to a second mode.