http://askubuntu.com – I connect to my beagleboard by using screen: screen /dev/ttyUSB1 115200 and when I connect to my beaglebone I open the dev/ttyO1 by screen also. Now, I want to close only the last screen connection. But I cannot. When I close the screen session with ctrl+a d, it does not only close the latest screen connection to ttyO1, it also closes the connection to the ttyUSB1,beaglebone. (HowTos)