摘要 |
An electronic demand register performs rolling demand metering in which a demand interval is divided into N subintervals. At the end of each subinterval, the demand data from the just-completed subinterval is summed with the demand in the most-recent N-1 contiguous subintervals to derive an interval demand. A test operation is provided in which the stored maximum demand, a number representing the remainder of the subinterval interrupted by the test and programmed constants are stored in non-volatile memory but are also retained in the processor for use during test. A test reset switch resets accumulated demand data and presets the subinterval timer to predetermined values from which they may be operated by a calibrated test load to confirm the performance of the demand register. At the end of testing, all data in the processor is zeroed and the data stored in non-volatile memory is restored. Demand metering is resumed starting with the remainder of the interrupted subinterval and with the demand from the N-1 prior subintervals set to zero.
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