Simulink.DataStore

R2026b

Specify instance-specific properties of data store

Since R2026b

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    Description

    Use a Simulink.DataStore object to represent a data store memory at the root level of a model. This object must be defined in the model workspace. Any Data Store Read block or Data Store Write block can access this data store if the block is located at the same hierarchical level as, or below, the data store object.

    Creation

    To create a Simulink.DataStore object:

    Syntax

    dataStoreObj = Simulink.DataStore
    dataStoreObj = Simulink.DataStore(signalObj)
    dataStoreObj = Simulink.DataStore(dsmBlkHandle)

    Description

    dataStoreObj = Simulink.DataStore returns a Simulink.DataStore object with default property values.

    example

    dataStoreObj = Simulink.DataStore(signalObj) returns a Simulink.DataStore object with the property values of the data store object set to the property values of the Simulink.Signal object indicated by signalObj.

    dataStoreObj = Simulink.DataStore(dsmBlkHandle) returns a Simulink.DataStore object with the property values of the data store object set to the parameter values of a Data Store Memory block, where dsmBlkHandle indicates the block handle. To obtain the block handle for a block, use the getSimulinkBlockHandle function. 

    dsmBlkHandle = getSimulinkBlockHandle('ModelName/dsmBlk',true)

    example

    Properties

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    Option to access the memory defined at a higher level in the model hierarchy, specified as a numeric or logical 1 (true) or 0 (false).

    When you set this value to 1, a subset of Simulink® blocks can access the elements of the DataStore object defined at a higher level in the model hierarchy. These blocks include the Data Store Read block, Data Store Write block, S-Function block, MATLAB Function block, MATLAB System block, and Chart (Stateflow) block. For more information, see Access Data Store at Higher Level in Model Hierarchy.

    Example: dataStoreObj.DataStoreReference = 1

    Limitations

    When you set the DataStoreReference property value to 1, these signal values are not supported:

    • 'auto' for DataType

    • 'auto' for Complexity

    • '-1' for Dimensions

    You must specify explicit values for these properties.

    Data Types: logical

    Option to allow multiple Model blocks to read from and write to the same data store, specified as a numeric or logical 1(true) or 0(false).

    In a single model reference hierarchy, when you use multiple Model blocks to refer to a model that contains a DataStore object, by default, each instance of the referenced model (each Model block) reads from and writes to a separate copy of the data store. When you set the ShareAcrossModelInstances property value to 1, instead of interacting with separate copies, all instances read from and write to the same data store.

    When you set the model configuration parameter Code interface packaging to Reusable function to generate reentrant code from a model (Simulink Coder™), a data store with Share across model instances selected appears in the code as a global symbol that the generated entry-point functions access directly. A global symbol is a global variable or a field of a global structure variable. Therefore, each call that your code makes to the entry-point functions (each instance of the model) shares the data.

    For more information, see Share Data Among Referenced Model Instances.

    Example: dataStoreObj.ShareAcrossModelInstances = 1

    Data Types: logical

    Specify that the data store interpret vector initial values as one-dimensional.

    By default, MATLAB® represents vector data as matrices, which have two dimensions. For example, MATLAB represents the vector [1 2 3] as a 1-by-3 matrix.

    When you select this parameter, the data store represents vector data by using only one dimension instead of two. For example, if you specify an initial value of [1 2 3], the data store stores a one-dimensional vector with three elements.

    For more information, see Determine the Output Dimensions of Source Blocks.

    Example: dataStoreObj.TreatVectorAs1D = 0

    Data Types: logical

    Diagnostic actions for the data store object, specified as none, warning, or error. The diagnostic options help Simulink to detect the sequence of read and write actions for a data store object.

    Use the Diagnostics property to create a DataStoreDiagnostics object to specify diagnostic actions for Simulink.DataStore objects.

    The diagnostic options are:

    • Detect Read Before Write — Select this diagnostic action if the model attempts to read data from a data store to which it has not written data in this time step.

      • none — This option is the default. This option does not produce any response.

      • warning — This option displays a warning and continues the simulation.

      • error — This option terminates the simulation and displays an error.

    • Detect Write After Read — Select this diagnostic action if the model attempts to write data to the data store after previously reading data from it in the current time step.

      • none — This option is the default. This option does not produce any response.

      • warning — This option displays a warning and continues the simulation.

      • error — This option terminates the simulation and displays an error.

    • Detect Write After Write — Select this diagnostic action if the model attempts to write data to the data store twice in succession in the current time step.

      • none — This option does not produce any response.

      • warning — This option is the default. This option displays a warning and continues the simulation.

      • error — This option terminates the simulation and displays an error.

    Example: dataStoreObj.Diagnostics.DetectReadBeforeWrite = 'warning'

    Data Types: char | string

    Dimensions of the data store, specified as a scalar, a vector, an array, or a matrix.

    The default value, -1, enables you to set the dimensions of the data store by using the InitialValue property. However, in this case, you cannot use scalar expansion with the initial value. You must specify the initial value by using an array that has the dimensions that you want.

    If you use a value other than -1, specify the same dimensions as the dimensions of the InitialValue property, unless you specify the initial value as a scalar (for scalar expansion) or a MATLAB structure. If the data store represents an array of buses, and if you use a MATLAB structure for the initial value, you can specify dimensions to initialize the array of buses with this structure.

    Example: dataStoreObj.Dimensions = 8

    Example: dataStoreObj.Dimensions = [1 myDataStoreDim]

    Data Types: double

    Initial value of the data store object, specified as a character vector or a string scalar.

    If you specify a nonscalar value and set Dimensions to '-1' (the default), the data store has the same dimensions as the array. Data that you write to the data store (by using Data Store Write blocks) must have these dimensions.

    If you set Dimensions to a value other than -1, the initial value dimensions must match the dimensions that you specify, unless the initial value is a scalar or a MATLAB structure. If you specify a scalar, each element of the data store uses the scalar as the initial value. Use this technique to apply the same initial value (the scalar that you specify) to each element without manually matching the dimensions of the initial value with the dimensions of the data store.

    To use this object to initialize a nonvirtual bus signal, specify the initial value as a MATLAB structure and set the model configuration parameter Underspecified initialization detection to Simplified. For more information about initializing nonvirtual bus signals using structures, see Specify Initial Conditions for Bus Elements.

    For enumerated data types, the initial value must be a member of the enumerated class. Suppose, you have an enum class, TrafficLightColors, with three members: Red, Yellow, and Green. To specify Green as the initial value, set InitialValue to TrafficLightColors.Green.

    Example: dataStoreObj.InitialValue = '5'

    Data Types: char | string

    Complexity of the data store signal, specified as real or complex.

    Example: dataStoreObj.Complexity = 'complex'

    Data Types: char | string

    Data store signal logging settings, returned as a Simulink.LoggingInfo object with its default property values. To learn more about how to override these values, see Simulink.SimulationData.LoggingInfo.

    Data Types: int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | logical | char | string

    Description of the data store object, returned as a character vector or string scalar.

    This property is used by the Simulink Report Generator and for code generation.

    If you have an Embedded Coder® license, you can add the data store description as a comment for the variable declaration in generated code:

    • Specify a storage class for the signal object other than 'Auto'.

    • On the Code Generation > Comments pane of the model Configuration Parameters dialog box, select the model configuration parameter Simulink data object descriptions. For more information, see Simulink data object descriptions (Embedded Coder).

    Example: dataStoreObj.Description = 'This data store contains a reusable algorithm'

    Data Types: char | string

    Output signal data type, specified as one of these values:

    • A rule that inherits a data type (for example, Inherit: auto).

    • The name of a built-in data type (for example, single).

    • The name of a data type object (for example, a Simulink.NumericType object).

    • An expression that evaluates to a data type (for example, fixdt(1,16,0)). Do not specify a bus object as the data type in an expression. Use Bus: <object name> to specify a bus data type.

    • If you have Computer Vision Toolbox™, use the constructor for the Simulink.ImageType (Computer Vision Toolbox) object and specify the properties to describe the image. By default, the data type uses the Simulink.ImageType(480,640,3) expression that represents the rows, columns, and channels of the image respectively.

    Example: dataStoreObj.DataType = 'double'

    Data Types: char | string

    Minimum value of the output signal associated with the data store object, specified as an empty array ([]) or real double scalar. The default value is [] (unspecified). This number must be a finite real double scalar value.

    Note

    If you specify a bus object as the data type for this object, do not set the minimum value for bus data on the object. Simulink ignores this setting. Instead, set the minimum values for bus elements of the bus object specified as the data type. For information on the Min property of a bus element, see Simulink.BusElement.

    Simulink uses the minimum value to perform:

    Example: dataStoreObj.Min = -8

    Data Types: double

    Maximum value of the output signal associated with the data store object, specified as an empty array ([]) or real double scalar. The default value is [] (unspecified). This number must be a finite real double scalar value.

    Note

    If you specify a bus object as the data type for this object, do not set the maximum value for bus data on the object. Simulink ignores this setting. Instead, set the maximum values for bus elements of the bus object specified as the data type. For information on the Maximum property of a bus element, see Simulink.BusElement.

    Simulink uses the maximum value to perform:

    Example: dataStoreObj.Max = 8

    Data Types: double

    Examples

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    Create a data store object A inside a model named mdlName. Replace mdlName with the name of your model for your application.

    Load the model.

     load_system("mdlName.slx")

    Create a data store object named A and add a description.

    A = Simulink.DataStore;
A.Description = 'Nonvolatile memory that stores state values during simulation.';

    Configure the data store object to access memory that is defined at a higher level in the model hierarchy.

    A.DataStoreReference = 1;

    Configure the signal associated with the data store object. To configure the signal, change the signal attributes according to your modeling requirements.

    A.DataType = 'double';
A.Complexity = 'real';      
A.Dimensions = [1 1];          
A.InitialValue = '5'; 
A.Min = -7;
A.Max = 7;

    Set up diagnostic checks.

    A.Diagnostics.DetectReadBeforeWrite = 'warning';
A.Diagnostics.DetectWriteAfterRead = 'error';
A.Diagnostics.DetectWriteAfterWrite = 'none';

    Set up how the data store logs data.

    A.LoggingInfo.DataLogging = 1;
A.LoggingInfo.LoggingName = 'State value';
A.LoggingInfo.DecimateData = 1;
A.LoggingInfo.Decimation = 3;
A.LoggingInfo.LimitDataPoints = 1;
A.LoggingInfo.MaxPoints = 4000;

    To specify these settings in the model workspace, use the assignin function.

    In the MATLAB Command Window, enter these commands.

    mdlWks = get_param(mdlName, 'ModelWorkspace');
assignin(mdlWks,'A',A);

    Alternatively, to specify the settings using the Model Explorer, follow these steps.

    1. On the Modeling tab, click Model Explorer.

    2. In the Model Hierarchy pane, from the model (modelName.slx) hierarchy tree, right-click Model Workspace node.

    3. Select the Properties menu item, which opens the Model Workspace dialog box. To load the settings, take one of these actions:

      • Save the configuration settings in a MATLAB (.m) file and load the file by setting Data source to MATLAB File.

      • Specify these settings directly as MATLAB code by setting Data source to MATLAB Code.

    Create a data store object from a Data Store Memory block. This example uses the Data Store Memory block named AAA from DataStoreMemoryBot.slx model in Access Data Store at Higher Level in Model Hierarchy. The Data Store Memory block has these properties:

    • Data store name is set as AAA.

    • Data store reference is selected.

    • Initial value is set to its default value of 0.

    • Data type is int32.

    • Dimensions is [1 1].

    • Signal type is real.

    Get the block handle for the Data Store Memory block AAA.

    blkHandle = getSimulinkBlockHandle('DataStoreMemoryBot/Data Store Memory',true);

    Create a data store object named dsobjAAA using the Data Store Memory block handle.

    dsobjAAA = Simulink.DataStore(blkHandle);

    To specify these settings in the model workspace, use the assignin function.

    In the MATLAB Command Window, enter these commands.

    mdlWks = get_param(mdlName, 'ModelWorkspace');
assignin(mdlWks,'dsobjAAA',dsobjAAA);

    Alternatively, to specify the settings by using the Model Explorer, follow these steps.

    1. On the Modeling tab, click Model Explorer.

    2. In the Model Hierarchy pane, from the model (modelName.slx) hierarchy tree, right-click Model Workspace.

    3. Select Properties, which opens the Model Workspace dialog box. To load the settings, take one of these actions:

      • Save the configuration settings in a MATLAB (.m) file and load the file by setting Data source to MATLAB File.

      • Specify these settings directly as MATLAB code by setting Data source to MATLAB Code.

    Extended Capabilities

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    C/C++ Code Generation
    Generate C and C++ code using MATLAB® Coder™.

    Version History

    Introduced in R2026b

    See Also

    Blocks

    Objects

    Topics