Is it possible to run multiple models that work together?

At this point I'm pretty sure I know the answer but I just wanted to see if anyone out there knows the secret. So we have multiple models, all of which take I/O via the standard I/O blocks as if they were subsystems to a larger system. When we compile the code/models to c code everything works great on the embedded board. Now we are getting tried of compiling every time we want to test something so we are looking for a way to run all these models together while passing signals from model to model. (Making one giant model where we truly make subsystems out of our models is not an option for us... The models are too large and we have them separated to allow us to test small sections without waiting hours for a result)

Thank you,