The method of setting the serial port speed of linuxrs485dp is as follows: In Linux system, the serial port speed can be set by stty command. The serial port device to be set is /dev/ttyub0, and the rate to be set is 9600bps. You can use the following command: stty-f/dev/ttyub09600. Where the -F parameter is used to specify the serial device file, and 9600 indicates the rate to be set. Note that when setting up the serial port, to ensure that you have enough permissions, you need to execute the command with root or sudo permissions. In the field of computer and communication, rate refers to the amount of data or signal frequency transmitted per unit time. It is expressed in bits per second (bps) or hertz (Hz). In data transmission, the rate represents the number of data bits transmitted per second. For example, the speed of the serial port is 9600bps, which means that the serial port can transmit 9600 bits per second.