Looking at the RC300 manual it can act as a slave, but it seems to suggest it does so only if it is a slave to another Master RC300? The normal operation is for the RC to act as a master.
I have linked the RC to a Steinberg UR22 audio interface via the midi port and tested the signal with ‘Midi-Ox’. I can see the BPM is being sent correctly from the RC to the computer via the UR22 when I rotate the tempo knob on the RC.
So it seems the RC is sending the time code but I cannot see how to get Cubase to sync to it as an external midi clock. I’ve gone into the project synchronization setup in Cubase but have been unable to get it to sync to the RC
I believe the clock is Midi Clock not MTC but I’m not sure of the difference and the manual does not give the info in the specs.
The midi sync of the RC is set to ‘Memory’ which relates to the tempo of each different ‘Phrase memory’
Beyond this I’m not sure what else I can add?