IWR6843: There is no data on the upper computer

I used the upper computer of IWR6843 to view the point cloud in the ROS environment.
In this case, two serial ports are required, one for transmitting commands and one for transmitting data.
However, for now we want to use a serial port to access the host machine.
For this reason, we modified the radar ROS project to set the radar to the self-starting mode, that is, it can work without transmission parameters.
We verified that the radar worked with the serial port test tool and transmitted the collected data from the remaining serial ports.
But when I use the host computer, there is no point cloud display on the host computer.
First, I changed the port Settings in the.launch file. I set both the command port and the data port to the same port. In this case, the host will report an error indicating that no done was sent back, and the host computer will not work.
The second time I removed the command port related Settings directly, in which case there was no command port.
Runtime shows empty port, still report error.
I don't know how to modify it now. Do you have any suggestions?