Siemens Power Transmission & Distribution, Inc.

Landis+gyr, Inc.

Gregory A Grisham

Gordon R Burns

Warren Thomas Martin

John P Junker

Randal K Bond

William James Watson

Michael K Anderson

A utility meter implementing the ANSI C12.19 standard is able to bypass security processing using Decade4 security tables for a single data access operation. The meter includes a procedure that is executed by a processor in the meter to process requests for security keys. Data internal to the meter is used to generate a security key. The security key is used by the requesting external device and the procedure to generate an access key. The external device sends its access key to the procedure so it may be compared to the internally generated access key. If both access keys are the same, a data access operation performed by the external device is allowed without reference to the Decade4 security tables. Once a timeout or data access operation is performed, subsequent data access operations are subject to processing in accordance with the Decade4 security tables unless another security key is requested for repetition of the process.

System and method for accessing read only ANSI tables in an electricity meter

An electrical utility meter includes measurement error diagnostic capabilities with intelligent communication capabilities. In an exemplary embodiment, the present invention includes an electrical utility meter for measuring energy consumption by a load. The electrical utility meter includes, sensor circuitry, a conversion circuit, a communication circuit, and a controller. The sensor circuitry connects to a meter socket. The meter socket connects to a plurality of power lines that, in turn, connect the load to a source of electrical power. The source of electrical power provides power to the load in a plurality of phases. The sensor circuitry generates voltage and current measurement signals representative of the voltage and current waveforms on the plurality of power lines. The conversion circuit is connected to the sensor circuitry and generates a power consumption measurement, as well as measured phase angle data for the plurality of phases, all of which are generated based on the voltage and current measurement signals. The communication circuit is connected to a remotely located control device. The controller is connected to the memory, the communication circuit, and the conversion circuit. The controller is operable to receive measured phase angle data for the plurality of phases, periodically perform a plurality of diagnostic tests using the measured phase angle data to determine whether a measurement error is present, and provide an alert signal to the communication circuit if a measurement error is present. The communication circuit, upon receiving the alert signal, is operable to obtain information identifying the measurement error and transmit an error signal containing information identifying the measurement error to remotely located control device.

Watt-hour meter with communication on diagnostic error detection

An electrical utility meter includes a controller that determines a list of highest demands using event-triggered windows of time to ensure that only one of the entries on the list corresponds to any one high consumption event. The controller generates a demand value corresponding to the quantity of energy consumed within a demand interval, and then determines whether the demand value for the demand interval is greater than a smallest demand value on a list of highest demands in a memory location. If so, the controller opens a demand window, the demand window having a duration exceeding the demand interval. The controller then obtains a plurality of additional demand values for the duration of the demand window, each of the additional demand values corresponding to one of a plurality of additional demand intervals within the demand window. The controller records in the list of highest demands in the memory location a select one of the demand value and plurality of additional demand values. The select demand value may suitably be the largest demand in the window.

Electrical utility meter with event-triggered window for highest demands

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West Lafayette, IN, United States of America

Gregory A Grisham