Subsystem cannot be defined to be a periodic function-call block because it has an asynchronous rate?

What does the error :

cannot be defined to be a periodic function-call block because it has an asynchronous rate.

in simulink mean?

Thank you, Carolina Sierra

[Kaustubha Govind]

It looks like this is a duplicate of your question at http://www.mathworks.com/matlabcentral/answers/44906-where-to-find-concurrent-execution-window-main-pane

[Walter Roberson]

Not really. The other question is about a specialized tool, with the question inspired while trying to solve this question.

On the other hand, the solution to this question happened to have been given over there.

Answer 1

[TAB]

Configure your function-call subsystem as triggered instead of periodic.

Read Function-call subsystems here.

[Jonathan Lee]

What if I set the Trigger block to 'triggered' and I still get this error mentioned above?