You will need to choose a channel, for instance channel 32, as a digital firewire input. In Studio One 2, make sure in the Audio I/O menu that you have the RM's outputs assigned. You can create a mono output and assign to channel 32. Click OK and exit the Audio I/O Setup menu. In the Studio One mixer, enable the "Outputs" tab. You will see your outputs as a mixer channel. Find the channel assigned to output 32. Enable the metronome for this channel by clicking the "Metronome" icon. When you start playback in Studio One with the click enabled, you should now see it's signal appear in the RM mixer for Channel 32.