Single Phase Electric Meter gradually developed into the second generation of time-sharing electric energy meter with mechatronics structure. This kind of electric energy meter adopts 1.0-level induction system electric energy meter core, adopts infrared photoelectric converter, pulse output and central processing unit (CPU), single-chip circuit, and uses the attached keyboard programming or infrared wireless keyboard to carry out various demands. The settings of, clock, time period, and weekends can protect the display and storage of the maximum demand of this month, the maximum demand of the previous month, and the peak, flat, and valley maximum demand of this month. With pulse output and RS-232 serial communication port, it is convenient for remote data transmission and monitoring. The performance of the instrument is more precise and reliable, and the function can meet the current time-sharing billing needs of our country. The production technology is relatively mature and the price is competitive. It is the most widely used generation product in China. But the fly in the ointment is that each manufacturer develops its own dedicated microcontroller, which has the disadvantages of poor product compatibility and difficult maintenance. Commonly used in this series of products are DF68, DF93, DTF33, DF86, DSF20, DIF-2, DF32, DSD66, etc.