How do you convert a virtual subsystem to a subsystem which can be converted to referenced model?

I have a working Simulink model, built up from a hierarchy of subsystems. I have been asked to modify it to take advantage of the benefits of referenced models. Procedure shown on http://www.mathworks.com/help/simulink/ug/converting-a-subsystem-to-a-referenced-model.html#bteeucq seems straightforward but I haven't been able to get it to work.

With a clean set of results from model adviser, and following all the steps. I get a popup saying "... You cannot convert a virtual subsystem to a referenced model."

So I started with a clean page, dropped in an adder and a gain block and grouped it into a subsystem. Connected a couple of sources and a scope and ran it - ok. I got the same "virtual subsystem" failure when I tried to convert it to a referenced model.

Maybe it doesn't like adder or gain blocks. So I again started from a blank page and dropped in a "subsystem" block from the Simulink library. Nothing inside except the default short of input to output. This is a virtual subsystem too.

So, how do you make a working collection of subsystems non-virtual?

Answer 1

[Guy Rouleau]

The subsystem need to be atomic.

Right-click on it, parameters, you should see a "Treat as atomic unit" checkbox.

http://www.mathworks.com/help/simulink/slref/subsystem.html#brp1xt9-56

[Robert Peruzzi]

That's the answer! Thanks, Guy.

[tom]

great！