I am looking at WizNet810 485 to ethernet module, about $20, and I always try to reduce/eliminate glue-logic. I have been using the wiz710 serial to e-net but the uart output of TX & RX has to be inverted. Thats why I was wondering about hooking directly to the module in-out with no other items on the 485 bus. I think the module has half and full duplex, selectable.

Don