Access Data Store at Higher Level in Model Hierarchy

This example uses:

Open Live Script

This example shows how to access the data stored in the Data Store Memory block at a higher level in the model hierarchy.

In this example:

  • The model has two hierarchical components: the top-level model DataStoreMemoryTop and the referenced model DataStoreMemoryBot. The Data Store Memory block at the top-level model defines the data store AAA.

  • An Event Scheduler creates function-call events based on the sine wave amplitude.

  • Based on the function-call events, the Data Store Read and the Data Store Write blocks within the referenced model access the data store AAA at the top-level model.

The DataStoreMemoryTop model shows its Model Properties dialog box open to the Callbacks tab.

Configure Blocks Inside the Referenced Model

At the top-level model, a Model block references to the DataStoreMemoryBot model. To allow the Data Store Read and Data Store Write blocks inside the referenced model to access the data store:

  • Place a Data Store Memory block inside a referenced model DataStoreMemoryBot. In the Data Store Memory block dialog box, select Data store reference. Set Data store name to the same value as the data store name: AAA.

The Data Store Memory Block Parameters dialog box shows the Data store reference option selected.

  • On the Signal Attributes tab, specify the Data type as int32, Dimensions as [1 1], and Signal type as real. These values are the same values as for the input signal mySig.

The Data Store Memory Block Parameters dialog box is open to the Signal Attributes tab.

Upon receiving the Read function-call signal at the read port of the Model block, the Data Store Read block reads data from the data store. The output is displayed at the Scope block. Similarly, when the model receives the Write function-call signal at the write port of the Model block, the input signal value 5 is multiplied by the Gain parameter value 2, and the Data Store Write block writes to the data store.

DataStoreMemoryBot model.

Model Function-Call Events Using Event Scheduler

Use a Stateflow® chart to model an event schedule that generates the Read and Write function-call events based on the sine wave amplitude. These function-call events control the execution of the DataStoreMemoryTop model.

Event Scheduler.

Review Results

Simulate the model.

out = sim('DataStoreMemoryTop');

The Scope block displays the simulation results.

The model executes based on function-call events. In the Scope block, the Control Signal (top row) and Output Signal (bottom row) represent the input to the Event Scheduler and the model output, respectively.

  • Between 0 to 3.2 s (approximately), the Control Signal value is either 0 or positive, which triggers the Read function-call from the Event Scheduler. Subsequently, the Data Store Read block reads the Initial value (-10) of the Data Store Memory block defined in the top-level model. The Scope blocks displays the Output Signal value as -10 until the next Read event is triggered at 6.4 s.

  • Between 3.2 s to 6.4 s (approximately), the negative value of the Control Signal triggers the Write function-call event from the Event Scheduler. Subsequently, the Control Signal value is multiplied by the Gain parameter and the Data Store Write block writes this value to the data store.

  • Between 6.4 s to 9.5 s (approximately), the Data Store Read block reads the value from the data store and displays the output in the Scope block.

See Also

| | |

Topics