9600 is the baud rate of this machine (also called rate, which is the data sampling frequency in unit time of communication transmission between navigation map program and navigation hardware). We should have two understandings about the gps port of the car navigator. One is the port and rate (baud rate) of navigation program (map program), which can be changed according to the port and rate of navigation hardware. The other is the port and speed set by the navigation hardware, which are fixed. When we install the navigation program, we must set the port and speed of the navigation program to be consistent with the port and speed of the navigation hardware, otherwise we can't receive the satellite (if the ports are inconsistent, we can't receive the satellite, if the speed is inconsistent, the communication fails and we can't guide the navigation).