This interface will allow you to control your VEX controller from your PC using either of the two communication ports on the controller. The quick way to get started is to download the VEXRobotics.exe into the Robotics Studio 4 Beta directory.
Run the exe and it will install the files need to run right away. (Make sure to read the read that is displayed during installation for more details.) You can now use VPL or C# to control your robot.