Distributed grid-connected interface devices are usually installed at 380V or 10KV grid-connected points, which provide measurement and control, protection, and power quality monitoring functions for the grid-connected points. At the same time, it also has protocol conversion and remote control functions. A communication bridge has been established between the two, which plays a role of "connecting the past and the next. Uplink transmits remote signaling, remote measurement, power quality and other information to the background, and accepts remote control and remote adjustment commands from the background master station. In addition, it forwards remote adjustment, start and stop commands to the downlink, such as inverters and converters.