Parts turn off when playhead loops back to the start in Reaper

[Steve]

That's true, but my problem is not that the clock isn't continuous, but that the parts turn themselves off after every loop. Is there no way around that?

Do you have a way to monitor the MIDI messages that Reaper sends at the time The NDLR stops playing?  

I think what Darryl is saying is that when The NDLR is set for external clock and no MIDI clock msgs are received, The NDLR will not play.  Same as the DSI Evolver example. 

Also if The NDLR gets two “stop” msgs in a row it will stop AND “disarm” all the parts. 
Thanks,
Steve