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Converting Harness-Driven Models to Use Harness-Free External Inputs

This example shows how to convert a harness model that uses a Signal Builder block as an input to a harness-free model with root inports. The example collects data from the harness model and stores it in MAT-files for the harness-free model. After storing the data, the example removes the Signal Builder block from the harness model and adds root inports to create a harness-free model. Then, the data in the MAT-files is mapped to the root inports of the model.

Save Harness Data to MAT-Files

Before converting the model to be harness-free, collect the test cases in the harness.

For this example, you will modify the model sldemo_autotrans from the Modeling an Automatic Transmission Controller example.

Open the example model. In the MATLAB Command Window, type sldemo_autotrans.

Exporting Signal Builder Block Groups

Export data that defines Signal Builder block signal groups to a MAT-file from the Signal Builder window. To export Signal Builder signal data, formatted as Simulink.SimulationData.Dataset, to a MAT-file, open the Signal Builder window and select File > Export Data > To MAT-File. In the dialog, enter a name for the MAT-file to contain the data and the number of the group you want to export. For this example, the file name is slexAutotransRootInportPassingManeuver.mat and the group number is 1 for the Passing Maneuver group.

Remove the Signal Builder Block

Remove the Signal Builder block named ManeuversGUI and replace it with two inports.

  1. Delete the Signal Builder block named ManeuversGUI.

  2. From the Simulink/Commonly Used Blocks library, drag two inport blocks into the model.

  3. Connect the input ports to the lines previously connected to the Signal Builder block.

  4. Rename the inport ports. Name the input port connected to the Throttle line Throttle. Name the input port connected to the BrakeTorque line Brake.

Save the model as slexAutotransRootInportsExample1.slx or use the example slexAutotransRootInportsExample.slx.

The remaining steps of this example use the model slexAutotransRootInportsExample.slx. If you saved the model with a different name use your model name in the steps going forward.

Set Up Harness-Free Inputs

Now that the model is harness-free, set up the inputs that you already saved (See "Save Harness Data to MAT-Files").

In the Modeling tab, select Model Settings. In the Data Import/Export pane, click the Connect Input button.

Map Signals to Root Inport

The Root Inport Mapper tool opens.

The example uses this tool to set up the model inputs from the MAT-file and map those inputs to an input port, based on a mapping algorithm. To select the MAT-file that contains the input data, click the From MAT-File button on the Root Inport Mapper toolbar. When the link dialog appears, click the Browse button. In the browser, select the MAT-file that you saved earlier.

Select a Mapping Mode

When you select the MAT-file slexAutotransRootInportPassingManeuver.mat that contains the input data, determine the root input port to which to send input data. Simulink matches input data with input ports based on one of five criteria:

  • Port Order - Maps in the order it appears in the file to the corresponding port number.

  • Block Name - Maps by variable name to the corresponding root inport with the matching block name.

  • Signal Name - Maps by variable name to the corresponding root inport with the matching signal name.

  • Block Path - Maps by the BlockPath parameter to the corresponding root inport with the matching block path.

  • Custom - Maps using a MATLAB function.

Earlier in this example, you saved input data to variables of the same name as the harness signals Throttle and Brake, and added input ports with names matching the variables. Given the set of conditions for the input data and the model input ports, the best choice for a mapping criteria is Block Name. Using this criteria, Simulink tries try to match input data variable names to the names of the input ports. To select this option:

  1. Click the Block Name radio button.

  2. Click the Options button and select Update Model. This verifies the mapping.

  3. Click the Map button.

When compiling the data, Simulink evaluates inports against the following criteria to determine compatibility issues. The status of this compatibility is reflected by the table colors green, orange, or red. Warnings and errors are flagged with diagnostic messages. If the Options > Update Model option is not selected, Root Inport Mapper determines the compatibility status by evaluating these block parameters and assigned signals:

  • Data Type - Double, single, enum, ....

  • Complexity - Real or complex

  • Dimensions - Signal dimensions vs port dimensions

Finalize the Inputs to the Model

Review the results of the mapping compatibility. Click the Scenario Dataset 'PassingManeuver' in the scenario dataset list. To prepare for simulation, click Mark for Simulation. This action applies the mapping variables to the Configuration Parameter Data Import/Export > External Input text box. If this text box has content, it is overwritten.

Simulating the Model

With the changes applied you can now simulate the model and view the results. Run the model. To view the results of the simulation, double-click the Scope Block PlotResults.