I connected a USB-serial-R45(10) to the port#4 for configuration through minicom. If I configured "set line range=1-4 baud=..." or "set line ..range=4", I got a "?" charcter return, not regular #>, then the configuration stuck (failed). Any subsequent connection return all "??..." I had to reset the device to start over again. I have to log in using the web gui after I configured the device with IP and then applied the "real port" profile on port#4, so I can use all ports for communication.