Follow the driver installation instruction that are provided with the keyboard. You can then run Artist. You will see the Edirol listed under the MIDI Manager section of the Resource navigator.
Artist is supplied with a patch for these keyboards and the PCR.DOC file contains printable overlay templates to identify the keyboard control function for ease of use.
After running Artist go to "Artist Help/Overview/Workspace/Patch Inputs/MIDI Inputs/Edirol PCR 30/50 Overlay" from the main menu. These outlines the set up procedure.