Electronic remote data recorder with facsimile output for utility AC power systems

An electronic remote data recorder with facsimile output for utility AC power systems comprising:

• a. a first analog measuring apparatus coupled to an AC power line for measuring voltage and current signals through the power line;
• b. a first isolation circuit coupled to the AC power line for isolating appropriate voltage levels from the voltage signal;
• c. a scaling circuit coupled to the first isolation circuit for scaling the signals;
• d. a first filtering circuit coupled to the scaling circuit for filtering unwanted frequencies out of the signals and forming a filtered signal;
• e. an integrating circuit coupled to the first filtering circuit for integrating the filtered signal over time;
• f. a multiplexing circuit coupled to the first isolation circuit, the scaling circuit, the first filtering circuit and the integrating circuit for multiplexing the signals;
• g. an analog-to-digital converter coupled to the multiplexing circuit for converting the signals from analog to digital thereby forming digital signals representing the signals;
• h. a second digital measuring apparatus coupled to switch contacts on the power line for measuring digital signals from the switch contacts;
• i. a second isolation circuit coupled to the second digital measuring apparatus for isolating appropriate voltages from the digital signals;
• j. a second filtering circuit coupled to the second isolation circuit for filtering out frequencies not of interest from the digital signals;
• k. a level shifting circuit coupled to the second filtering circuit for shifting the level of the digital signals to an appropriate level;
• l. a digital multiplexer coupled to the second isolation circuit, the second filtering circuit and the level shifting circuit for multiplexing the digital signals;
• m. a first microprocessor coupled to the analog-to-digital converter and the digital multiplexer;
• n. a first RAM coupled to the first microprocessor for storing system data and accumulated measurement data;
• o. a first ROM coupled to the first microprocessor for storing data and instructions used by the first microprocessor;
• p. a real-time clock and calendar coupled to the first microprocessor for keeping the current time and date accessible by the first microprocessor;
• q. a second microprocessor coupled to the first microprocessor, the first RAM and the real-time clock and calendar for issuing a report of the accumulated measurement data when triggered by the first microprocessor;
• r. a second RAM coupled to the second microprocessor for storing setup and system data and a format for the report;
• s. a second ROM coupled to the second microprocessor for storing data and instructions used by the second microprocessor;
• and
• t. a facsimile modem coupled to the second microprocessor for communicating with other remote systems for receiving the setup data and for transmitting the accumulated measurement data to a remote system periodically or upon a trigger condition.