程序将来自TCP服务端发送过来的数据转到串口发送出去，将接收的串口数据转发到TCP服务端，架起了TCP与串口通讯之间的桥梁。(The program will send data from the TCP server to the serial port to send out, and will receive the serial data forwarded to the TCP server, set up a bridge between TCP and serial communication.)