​The relay coil is represented in the circuit by a long box symbol, and if the relay has two coils, two long boxes are drawn side by side. At the same time, mark the relay word symbol "J" in or beside the long box. There are two ways to represent the contacts of relays: one is to draw them directly on one side of the long box, which is more intuitive. The other is to draw each contact into its own control circuit according to the needs of the circuit connection. Usually, the contact of the same relay and the coil side are marked with the same text symbol, and the contact group is numbered to show the difference.

In summary, the latching relay is not merely a switch within a smart energy meter; it is a strategic component that addresses core challenges of power efficiency, long-term reliability, and advanced functionality. By eliminating standby power draw, it unlocks decade-long battery life and enables new, autonomous meter designs. Its inherent thermal and mechanical stability ensures operational integrity over the meter's extended lifespan. Finally, its bistable, pulse-driven nature is the perfect interface for executing remote commands and smart grid functions, from prepayment to demand response. Specifying a high-quality latching relay, therefore, is a fundamental design decision that directly impacts the performance, longevity, and intelligence of the smart metering system.