The DH485 Router/B now supports an isolated DH485 port. The module has a RS232 port as well which allows for RS232 to RS485 conversion (and vice versa) which can then be used as a pure 1761-NET-AIC replacement.

The module also has an embedded switch which will allow the DH485 Router/B to operate in a EtherNet/IP DLR ring.
See  DH485 Series B.