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Specify Requirements Table Block Properties

You can specify how a Requirements Table block interfaces with a Simulink® model by setting the block properties in the Property Inspector, the Table Properties window, or the Model Explorer.

To use the Property Inspector, click the Modeling tab, and In the Design section, select Property Inspector. Click the Requirements Table block to see the Requirements Table block properties.

To use the Table Properties window, open the block. In the Simulation tab, in the Prepare section, click Table Properties.

To use the Model Explorer, click the Modeling tab and in the Design section, select Model Explorer. In the Model Hierarchy pane, expand the model tree view, select the Requirements Table block, and edit the properties in the Requirements Table pane.

Requirements Table Block Properties

You can adjust these properties in the Properties tab of the Property Inspector or in the General tab of the Model Explorer or Table Properties window.

Update method

Specifies the method used to activate the Requirements Table block.

Update MethodDescription

Inherited

(default)

Input from the Simulink model activates the Requirements Table block.

If you define input data, the Requirements Table block samples at the rate of the fastest input data. If you do not define input data, the Requirements Table block samples at the rate defined by the execution behavior of the parent subsystem.

DiscreteSample the Requirements Table block by using the rate you specify in the Sample time property of the Requirements Table block. The Requirements Table block generates an implicit event at regular time intervals that correspond to the specified rate. Note that other blocks in the model can have different sample times.

Support variable-size arrays

Specifies that the Requirements Table block supports output and local data that varies in dimension during simulation. See Variable size.

Saturate on integer overflow

Specifies that integer overflows saturate in the generated code. See Saturation and Wrapping (Fixed-Point Designer).

Enable outputs in preconditions

Allow data with Scope set to Output to be used in preconditions. If you disable this property, the block highlights the cell and displays an alert icon in preconditions that use output data, unless the data is an input argument of getPrevious. However, if getPrevious attempts to return the value of the data at a time step when it was not defined, getPrevious returns undefined behavior.

When you use output data in preconditions, you may encounter read-before-write issues in your requirements during simulation. To resolve these issues, specify your requirements in order. For more information, see Troubleshoot Requirements Table Blocks and Leverage Evaluation Order of Formal Requirements.

Fixed-Point Properties

You can adjust these properties in the Properties tab of the Property Inspector or by opening the Fixed-point properties tab in the Model Explorer or the Table Properties window.

Requirements Table fimath

Specifies the fimath properties for the Requirements Table block. The fimath defined in the Requirements Table fimath text box behaves as a globalfimath (Fixed-Point Designer) for the contents of the Requirements Table block. The block associates the fimath properties in the Requirements Table fimath text box with the fixed-point and integer input signals to the Requirements Table block that you choose to treat as fi objects. When you construct fi objects in the Requirements Table block, note that:

  • If no fimath is associated with a fi object when it is constructed, then the fi constructor uses the default fimath settings regardless of the properties in the Requirements Table fimath text box. However, if you perform additional operations on the fi object after it is constructed, the object adopts the properties in the Requirements Table fimath text box.

  • If you specify a fimath in the fi constructor, then that fimath is obeyed when quantizing the value in the fi constructor. fimath settings not specified in the fi constructor use the specified properties in the Requirements Table fimath text box.

You can select one of these options:

SettingDescription
Same as MATLAB

The block uses the same fimath properties as the current default fimath. The text box is dimmed and displays the current global fimath in read-only form.

Specify Other

You can specify your own fimath object in the text box. You can do so by either:

  • Constructing the fimath object inside the text box.

  • Constructing the fimath object in the MATLAB® or model workspace and then entering its variable name in the text box. If you use this option and plan to share your model with others, define the variable in the model workspace. For more information on fimath objects, see fimath Object Construction (Fixed-Point Designer).

Description and Document Link Properties

You can set description and document link properties for the Requirements Table block in the Info tab of the Property Inspector, or in the Documentation tab of the Model Explorer or Table Properties window.

Description

Specifies the description of the Requirements Table block. You can enter a brief description and comments.

See Also

Related Topics