Thank you for your reply, I think you are right, they seem to have the full TCP/IP operation, and maybe they just do not open it to users.That depends how the port is configured & for what protocols!
If it supports full TCP/IP operation, then what's the difference from having a single ethernet port on a PC or any other device - it connects to an ethernet switch, either stand-alone or part of a router, then on to other devices or the internet etc.
I can see the location where it is connected to the host computer communication has two interfaces, one is the Ethernet port, the other is the USB port.It appears all the configuration has to be done via the "Stone designer GUI editor" program.
Does that have any options to select which port is used to connect with the host system? The datasheet shows communications via ethernet, but that may well only apply to duplicating the same comms as used via the serial port & no other functions.