I wonder if you connect the R16 to your PC and connect the keyboard midi to the PC, then they should sync with a DAW open. (i would hope you don't need to record to the DAW but could record to the memory card on the R16) I don't know this unit too well unfortunately, but the PC would be able to pass-thru the midi time code pulses. I'm guessing the R16 must have midi in it, even if it's not got a physical socket. It's funny though, because no-one has ever asked me about this in the store. hmmmm... vey interesting. Thanks for posting your query.
Roland G-70, FP-4, BK-7m, SonicCell, KC-350 x 2, DS-5 x 2, A300-Pro, Sonar X1 PE, BR1600CD
Yamaha HX-1 System 1, KA-20x2