Your master IO board can be the 1072_0 SBC2
. It is a small computer running Linux. It can be connected to your home network using either Ethernet cable or a WiFi dongle. Other boards can be connected to the SBC2 from USB.
Your program can be run directly on the SBC2, or you can have your main PC communicate with it.
We currently do not have an RS-485 solution, but that is something for us to look into eventually.