Model Multirate Signal Processing Systems Using Dataflow

This example shows how to model multirate signal processing systems using the dataflow subsystem. When you set the domain of a subsystem to dataflow and enable the Automatic frame size calculation parameter, the software calculates the signal sizes of frame-based multirate models and inserts buffers so that the model compiles with no frame size propagation errors.

For more information on dataflow domains, see Dataflow Domain. Below is an example of a multistage filter.

1. The subsystem of this model contains several rate conversion blocks.

   

2. When the model diagram is updated, Simulink^® generates an error due to a port dimension mismatch in the model. To fix such an error, set the domain of the subsystem to dataflow.

3. To set the domain of the subsystem to dataflow, if the Property Inspector is not visible, in the Modeling tab, under Design, select Property Inspector.

   With the subsystem selected, in the Execution tab of the Property Inspector, select Set execution domain. Set the Domain to Dataflow.

4. Observe that when Automatic frame size calculation is selected, the software automatically calculates frame sizes and inserts buffers where needed.

5. After updating the diagram again. The model now updates successfully.

   

Badges on the model canvas at the input of the subsystem indicate where buffers are inserted.