Revision history [back]

There is some confusion here. It is impossible for both of these devices to be on the same port.

The launch files may be setup with the same port name but this is just where the respective ROS nodes will be expecting the hardware to be it in no way controls which port they are on.

The simplest way to fix this is to unplug both devices and run ls /dev/tty* then plug one of them in and use ls /dev/tty* again to find out the port name of the new device. Then plug the second device in and repeat to find its port name. Then you can update the launch file with the correct ports for each device. However to avoid doing this every time, which is a huge pain, a more complex but automatic solution is possible

This trick to use multiple serial over USB devices with ROS involves setting some UDEV rules so that each device will automatically be identified when it's plugged in and a symlink with a constant name is linked to it. This technique is described here.

Hope this makes sense.