Noely,
Do you want to use the RS-485 network to control the FieldPoint bank or are the sensors on a RS-485 network? If you are looking for a FieldPoint controller that is controlled via RS-485 look at the FP-1001. If you are looking to communicate on a RS-485 network then look at the cFP-2020 (embedded real-time controller) or the FP-1000 (RS-232 with a RS-485 repeater port).
Ames