How can I include an Enable/Trigger block at the root level of a Simulink model?

I would like to include an Enable block at the root level of my Simulink model. This returns the following error message:

 Trigger, enable and action ports are not allowed in the root window of a block diagram.

I would also like to be able specify port attributes in these blocks.

Answer 1

[MathWorks Support Team]

This enhancement has been incorporated in Simulink (R2011b). For previous product releases, read below for any possible workarounds:

The ability to include Enable/Trigger/Action ports in the root level of a model is not available in Simulink.

To work around this issue, you may use the Model Reference block in an enabled or triggered subsystem.