I think the Baudrate is variabel. The device isnt deliverd until now. It has an USB Port which you can connect to a PC as Virtual Com Port. It is the Rohde-Schwarz 8015.
Yes , the Due has 4 serial Ports. 1 is sending Data to a PC for Excel, another one is comunicating with an older Power Meter, the Hameg 8115-2, which provides a “real” serial hardware connection.
I think at first I will try to communicate with a windows PC to it, to see how it will behave. After that I will try to link Arduino and the 8015 with the tool Com0Com over the same PC. (Is there a similar tool for Raspbian ?)
Thank you for your Answers!