RS232 is a serial communication interface standard used to transfer data between computers and external devices such as printers, modems, instruments, etc. It is an asynchronous communication interface that supports full-duplex communication with transmission rates up to 115200bps. RS232 interfaces usually use DB9 connectors, which include 9 pins for transmitting data, receiving data, sending requests, receiving requests, signal ground, etc. RS232 interface has been widely used in the field of computer communication, and is a very common interface standard.