SerialPort DataReceived event not firing?

Question

The following code shows how to connect to a serial port using a C# and write a "Hello World!!!" message to the serial device "Customer Display".

public Form1()
    {
        ComPort = new SerialPort();
        
        ComPort.PortName = "COM2";
        ComPort.BaudRate = 9600;
        ComPort.DataBits = 8;
        ComPort.StopBits = StopBits.One;
        ComPort.Handshake = Handshake.None;
        ComPort.Parity = Parity.None;
        ComPort.DtrEnable = true;
        ComPort.RtsEnable = true;
        ComPort.PinChanged += new SerialPinChangedEventHandler(PinChanged);
        ComPort.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived_1);
        
        ComPort.Open();
        
        ComPort.Write("Hello World!!!");
    }
    
    private void port_DataReceived_1(object sender, SerialDataReceivedEventArgs e)
    {
        InputData = ComPort.ReadExisting();
    }
    
    private void PinChanged(object sender, SerialPinChangedEventArgs e)
    {
        //some code
    }

Unfortunately, a DataReceived event does not fire, Why?

Answer 1

客户显示设备类似于显示器，因此它通过串行端口从 PC 接收文本或命令消息，但不会向 PC 发送任何内容。