Okay, found two terminal emulators that work on the Pi with Stretch...
PuTTY and Cutecom
Standard install...
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install putty
or
sudo apt-get install cutecom
Found my loop back DB9 (2-3,4-6,7-8)
Set the port settings in each program for ttyUSB0 or ttyUSB1 and can see data.
If that works then there no problem with the USB dongle. We have some other problem either with JMRI end or C/MRI end.
Jim Albanowski
