This shield is the newest version 2.1
Now you will be able to have a communication port for your field bus directly connected to your Arduino! Even though the RS485 is sometimes thought as an “archaic” protocol, it will allow up to 32 devices to communicate through the same data line over a cable length of up to 4000ft with a maximum data rate of 10Mbit/s. Those aren’t bad numbers!
This version of the RS485 shield removes the optional DB9 connector bay and adds a second 2-pin screw terminal and the ability to choose two pins from your Arduino’s D0 to D7 as Software Serial Ports to communicate with the shield.