The IP address for the controller should be on the screen. It defaults to 192.168.1.50, but there are so many different things that can set it (such as DHCP) to a different IP. Check the screen.
You can also set the IP and the netmask from the board controls. See the user manual, linked from the F4V3 page on pixelcontroller.com. (https://docs.google.com/document/d/1CZ1rDMsKNkaTfZemvHUTL8JH9NVjtndyzC0qlMYAOz4)