Combo Box

Select parameter value from drop-down menu

  • Library:
  • Simulink / Dashboard


The Combo Box block lets you set the value of a parameter to one of several values. You can define each selectable value and its label through the Combo Box block parameters. Use the Combo Box block with other Dashboard blocks to build an interactive dashboard of controls and indicators for your model.

Double-clicking the Combo Box block does not open its dialog box during simulation and when the block is selected. To edit the block's parameters, you can use the Property Inspector, or you can right-click the block and select Block Parameters from the context menu.


Dashboard block controls connect to variables and block parameters. To connect a Dashboard block to a variable or parameter, use the Connection table in the block's parameters.

  1. Double-click the block.

  2. Populate the Connection table by selecting blocks of interest in your model.

  3. Mark the option button next to the parameter or variable you want to adjust during simulation.

  4. Click Apply.


  • You cannot save the block connections or properties in model files that use the MDL format.

    To save connections and properties, save the model file in the SLX format.

  • Dashboard blocks can only connect to real scalar signals.

  • Dashboard blocks cannot connect to blocks that are commented out.

  • Dashboard blocks cannot connect to signals inside reference models.

  • Parameters specified by indexing a variable array do not appear in the Connection table. For example, a block parameter defined using the variable engine(1) does not appear in the table.

    To access the parameter in the Connection table, assign the indexed value to a scalar variable, such as engine_1. Then, use the scalar variable to define the block parameter.


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Select the block parameter to control using the Connection table. To open the dialog box, double-click the block. Then, populate the Connection table by selecting a block in your model. Select the variable parameter you want to control, and click Apply.


To see workspace variables in the connection table, update the model diagram with Ctrl+D.


Values assigned to the connected parameter when you select the option with the corresponding Label. Click the + button to add options.

Label for each option. You can use the Label to display the value the connected parameter takes when the switch is positioned at the bottom, or you can enter a text label.

Example: Gain = 1

Position of the block label. When the block is connected to a signal, the label is the name of the connected signal. When the block is not connected, the label is the instructional text.

Introduced in R2017b

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