Data processor apparatus for multitariff meter

TL;DR: In this article, the meter includes a kilowatthour register which is continuously engaged as well as at least one special register (kilowattthour or demand) which is selectively engageable.

Abstract: The meter includes a kilowatthour register which is continuously engaged as well as at least one special register (kilowatthour or demand) which is selectively engageable. A calendar memory (ROM) stores data representative of schedule events and the times (called "calendar times") at which such events are to be effected. The events may include the engagement of a special register or controlling a load under customer programming. A Central Processor Unit (CPU) deriving timing information from the line frequency generates real time data and compares it with the stored calendar time for implementation of a schedule event. When the schedule event time arrives, the CPU implements the event (as by energizing an appropriate register selection circuit) and addresses the next schedule event in the calendar memory. The system includes a display for the real time data as well as means for setting the time data. In the event of a power outage, a battery carryover is provided, in which case, the CPU generates the real time data from its crystal clock and causes the system to enter a power conservation mode in which the display is disabled and the special registers cannot be engaged. The CPU re-initializes itself with the next schedule event whenever the time is set, or the calendar memory is removed, or the real time clock "rolls over" at midnight, or when AC power is re-established following a power outage.