Community charging pile refers to the charging equipment that provides charging service for electric vehicles. The charging pile can realize charging by time, electricity degree and amount, and can be used as a terminal for citizens to purchase electricity. At the same time, in order to improve the efficiency and practicability of the public charging pile, a multi charging and charging function for electric bicycles will be added in the future.
The charging pile in the community generally provides two charging methods: conventional charging and fast charging. People can use a specific charging card to swipe the card on the human-computer interaction interface provided by the charging pile to print the corresponding charging method, charging time, cost data, etc. The charging pile display screen can display the charging amount, cost, charging time, and other data. The input end of the charging pile in the community is directly connected to the AC power grid, and the output end is equipped with a charging plug. As the charging pile of the electric vehicle community on the power side of the power grid, the particularity of its structure determines that the characteristics of the automatic communication system are that the measured points are many and scattered, the coverage is wide, and the communication distance is short. With the expansion of the city, the network topology requires a flexible and expandable structure. Therefore, the following issues should be considered in the selection of the communication mode of the charging pile in the electric vehicle community:
（1）Reliability of communication - the communication system shall withstand the test of harsh environment and strong electromagnetic interference or noise interference for a long time, and keep the communication unblocked.
（2）Construction cost - under the premise of meeting the reliability, the construction cost and long-term use and maintenance cost shall be comprehensively considered.
（3）Two way communication - it can not only upload information, but also release control quantity.
（4）Multi service data transmission rate - With the continuous growth of terminal traffic in the future, the communication between master station and sub station and between sub stations and terminals requires higher and higher data transmission rate to achieve multi service.
（5）Flexibility and scalability of communication - Because the charging pile in the community has many control points, wide areas and decentralized characteristics, it is required to adopt standard communication protocols. With the expansion of the "ALLIP" network technology trend and the continuous growth of power operation business, it is necessary to consider the IP based business bearer, and it is required to facilitate installation, construction, commissioning, operation and maintenance.