Power (red) is the module's power indicator, which lights up when the module is powered on. Data (blue) lights up when the module is connected to the server, flashing alternately roughly once per second. At this point, the module can send or receive data normally. If there is sending or receiving on the network side, it flashes rapidly. Network (green) indicates the module's downstream communication. It flashes quickly when there is data being sent or received on the downstream communication port. If there is sending but no receiving, the blinking will have pauses. When the network (green) is not blinking (meaning the module is not connected to the server), possible situations are: A, server parameters are incorrect or the server is faulty; C, network issues; D, module itself is faulty.
