Thanks for the link, but it does not address the question, the link looks like a discussion for Universal-Devices to create there own PLM device, which is cool.
That being said I no longer have a hub because it failed, so I switched to the ISY w/serial PLM. When I did use the hub I was able to access via tcp using an interface I created with LinuxMCE, in addition to direct TCP socket using perl on a linux box. The hub accepted all commands that could be sent via tty with the serial PLM modem (linking, database updates etc.). I just thought it would be great to be able to open a socket to the hub via tcp rather than via serial only this would give access to people who already own the hub, but would like more advance controls.