This book
http://www.amazon.com/Event-Based-Programming-Taking-Events-Limit/dp/1590596439/describes an FBP variant for .Net, using C#'s "delegate" and "event" built-in types.
AFAICT, events are "output ports" and delegates are function signatures for the callbacks to the input methods that accept notifications from events.
He develops a diagramming methodology, but appears not to have a diagram compiler (plug: that could easily be repaired with techniques such as
https://github.com/guitarvydas/vsh ).
(And, I see 4 other books about events listed at the bottom that I don't remember seeing before. Maybe steam engine time is gathering steam?)