Driver (Not always required)
https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers
PuTTY, or your own terminal program http://www.putty.org/
D72 Menu 3,3 9600
D72 Menu 3,5 On
Connect via USB
Check Device Manager for Serial Port
Use above driver if driver not found
Launch putty
Choose Serial
Enter Com Port COM3
Speed defaults to 9600 leave it
Terminal, check Implicit LF in every CR
Open