I am needing to use an Arduino board that has RS-485 compatibility that can communicate with a non Arduino device that uses BACnet. I am planning on having the communicate over RS-485 to send and receive data. I know how to connect two Arduino boards over Serial to communicate with each other, but not two different devices. Would the way to send point data be more or less the same, where the master device sends a value over and the slave device uses that as the event trigger to pass a value point back, or will this have to be set up differently. The BACnet device will be acting as the master device for this.
I mostly only need to get the value of a multistate variable from the BACnet device for these tests. Any help or ideas would be appreciated.