US 4,400,783 AGranted

Event-logging system

AssigneeWestinghouse Electric Corp.

InventorsPhilip F. Locke, Jr., Albert H. Maxwell, Jr.

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Abstract

A solid-state event-logging system records the occurrence of specified events in a removable, solid-state, memory cartridge. Counters continuously count pulses produced by a plurality of electrical energy measuring devices. Sample values of the continuous counts are produced and input to a microprocessor wherein each sample value has the previous sample value subtracted therefrom. The difference is added to an interval sum stored in a random access memory. The interval sums, together with real time information produced by a clock, are input to the memory cartridge according to a predetermined format. The clock is maintained in synchronization with the frequency of the line voltage by the microprocessor.

Claims52

Dependent claims

An event-logging system for recording digital data from a plurality of electrical energy metering devices, comprising:

input counters for continuously counting the pulses of the digital data, said counters producing a plurality of running counts each representative of said data produced by one of the metering devices;
control means for producing a plurality of control signals;
means for sampling said running counts, said means producing sample values of each of said running counts in response to said control signals, each of said sample values being input to said control means wherein said sample value has the previous sample value subtracted therefrom, the difference from said subtraction added to an interval sum stored in said control means;
means for producing an interrupt signal composed of pulses responsive to the frequency of a line voltage, said interrupt signal input to said control means, said control means producing a clock interrogation signal responsive to said interrupt signal, said control means producing a synchronization count in response to said pulses of said interrupt signal;
clock means producing real time information, said real time information input to said control means in response to said clock interrogation signal, said synchronization count compared by said control means to a predetermined value at preselected times, said clock means being reset by said control signals in response to said comparison such that said clock means is kept in synchronization with said line voltage;
a cartridge comprising removable solid state memory means;
and
output interface means, said means inputting said real time information and said interval sums to said removable memory means according to a predetermined format in response to said control signals, said control means resetting said interval sums to zero upon the recording in said removable memory means of said interval sums.

5 more elements

An event-logging system for recording digital data from a plurality of electrical energy metering devices, said system powered by a primary voltage source and comprising:

input counters for continuously counting the pulses of the digital data, said counters producing a plurality of running counts each representative of said data produced by one of the metering devices;
a microprocessor for producing a plurality of control signals;
a read only memory for containing preprogrammed information;
a random access memory, said microprocessor transferring a portion of said preprogrammed information from said read only memory to said random access memory;
means for sampling said running count, said means producing sample values of each of said running counts in response to said control signals, each of said sample values input to said microprocessor wherein said sample value has the previous sample value subtracted therefrom, the difference from said subtraction added to an interval sum stored in said random access memory;
means producing an interrupt signal composed of pulses corresponding to the frequency of a sixty hertz line voltage, said interrupt signal input to said microprocessor, said microprocessor producing a clock interrogation signal responsive to said interrupt signal, said microprocessor producing a synchronization count responsive to the pulses of said interrupt signal;
clock means producing real time information, said real time information stored in said random access memory in response to said clock interrogation signal, said synchronization count compared by said microprocessor to a predetermined value at preselected times, said clock means being reset by said control signals in response to said comparison such that said clock means is kept in synchronization with said line voltage;
removable memory means;
output interface means receiving a stream of data from said random access memory and inputting said stream of data to said removable memory means according to a predetermined format in response to said control signals, said stream of data including said real time information, a portion of said preprogrammed information and said interval sums, said microprocessor resetting said interval sums to zero upon said stream of data being correctly recorded in said removable memory means;
a power outage detection circuit responsive to failure of the primary voltage source for producing a power failure signal;
and
a transmission gate selectively connecting said random access memory and said microprocessor in response to said power failure signal.

9 more elements

Dependencies are inferred from the claim text.