I connect flight controller with rpi by serial port, and like to communication with SITL in my PC by udp.
so I run this
roslaunch mavros apm.launch fcu_url:=/dev/ttyACM0:921600 gcs_url:=udp://@my_pc_ip
this run well.
buy when I want to get /mavros/imu/data_raw at the same time, and set the stream rate in 100. it can not work in normal way. when udp is sent, the stream rate of mavros/imu/data_raw is reduced.
I repead the same test in px4, all of these work well.