RS485 Circuit on 2 arduinos

Hello all I'm looking for info about RS485 communication using MAX485 or another chip converter.I want to communicate with two arduinos using this protocol at a 400m distance thanks

Here's a starting point:

Please let us know how it worked out!

For a simple point to point link I'd just use a 485 "full duplex" transceiver (has A, B, Z and Y pins, the LTC490 is an example) at each end with the standard 120R termination.

That will look exactly like a normal serial port to your application, no mucking around with half duplex issues.