The PRS-7921 Energy storage local control terminal is an Ethernet-based intelligent logic unit introduced by CYG SUNRI using mature computer technology and network communication technology by summarizing years of experience in the development and operation of substation integrated automation systems. The purpose of this terminal is to satisfy the requirement of online monitoring of energy storage stations and the development of higher-level system monitoring.As a communication device of comprehensive automation system deployed in the substation, PRS-7921 follows the DL/T860 protocol, which is connected the BMS, PCS and the higher-level monitoring system in the station, and coordinates the data and command interaction between various devices and monitoring terminals. Specifically, it receives data sent by the online monitoring device in real time, aggregates, displays, processes, analyzes and stores the data, and realizes the control of energy storage device and standard communication with the higher-level system.