About the Load/Save Configuration Tool

RT-LAB contains various features that provide flexibility and versatility while testing. One of these is the Load/Save Configuration tool, which allows you to test various combinations of parameters on-the-fly without changing the underlying model.

For example, on a parameter you are testing, you may choose to build three sets of values, X, Y, and Z. You may then load them, one at a time, sequentially, and watch how your results are affected. You may then choose to save the most favorable results, or the ones that most interest you, and/or make a choice to overwrite the default values.

Using Load/Save Configuration

Locate the Current/Updating Value of a Variable

• Start RT-LAB with the rtdemo1 model
• Uncollapse the folders Models, rtdemo1, and then sm_computation in this order.
• Uncollapse one or more of the Gain folders, for example:

• You’ll note that the folder contains a parameter or variable, in this case, labeled Gain, and a signal (with a distinct icon), which is numbered. 
• In this example, above, we've also opened the Gain Kd and Gain1 variables, which also contain signals.

• For the purposes of this exercise, we’re concerned with the parameter or variable, labeled Gain.
• Ensure the lower right window has the Variables Table tab open and selected, and drag and drop the Gain signal into this tab.
• Do the same with the Gain Kd and Gain1 signals.
  

  • If the Variables Table doesn't appear in your interface at this point, it can be opened through Windows > Show View > Variables Table.

• The three Gain values appear in the Variables Table.
• This is how you will view the current and dynamically changing (updating) values of this and other variables. (Note the Value column.)
• Note that only Parameters are editable. Signals are read-only.
  

Check Your Pre-existing Parameters/Variables

A model will have pre-defined parameters or variables.

• Right-click rtdemo1 (your model) > Edit with > MATLAB [version].

• The Opening Model dialog is displayed in the lower left, and your model opens.

• Double click the sm_computation block in MATLAB Simulink, and then, for example, double-click the Gain icon.

• The Block Parameters: Gain dialog appears. This is the current value of the Gain parameter, in this case, 1.
• Note the dialog also has Signal Attributes and Parameter Attributes tabs.

Every time the model is reset, the value resets to its model default value.

Edit Values/Parameters in the Variables Table Viewer

• Double-clicking the Gain entry in the Variables Table shows the Gain value in the Variable Viewer.
• You can also click in the value text box of Parameters to change the value.
  

• Knowing where the variables are pulled from, how they propagate the simulation, and where they are displayed, we are now ready to set up alternate parameter sets.

• In a typical use case, you may have three parameter sets you are testing, where one ends up to be too much, one too little, and the third just right.

• To change a parameter, select it, then click its Value in the lower-right window > Variables Table, and edit it manually.

• In the upper-right window, click the rtdemo1 tab > the Simulation Tools tab, then note the Configuration > Save and load parameters in Configuration checkbox at the bottom of this tab.

• When this box is checked, multiple configurations and thus multiple .param files are allowed.

• Right-click the Configuration folder in the left margin, and you have a choice of: 

Save, Load or Delete Configurations

• In this case, we’ll Save configuration as…

• A dialog appears, called Parameters in configuration. Do you wish to save parameters?

This gives you the option to:

Continue Building Variable Sets & Configuration Files

• If you are interested in building a suite of parameters sets, click Yes, from active values.
• A naming dialog appears where you are asked to enter a Name for the configuration.
• Enter a name that is meaningful to you (i.e., Gain_testing_value) and click OK. 
  • If you are testing several values, i.e., 6, 8, 10, 12, you may want to include these in the configuration name, so that you can tell from the name along which signal value is being tested.
• Load and Execute your model, and the current configuration is used.
• Continue Saving configurations as…, using your suite of selected values, and continuing to edit them manually in the Variables Table, until you have populated the RT-LAB interface with the values/parameters you’d like to test.
• Note that you may need to Reset, Load, or Execute between setting up and loading configuration files, as indicated by the on-screen prompts and/or error dialogs.
• When you select Load Configuration from the Configuration > Right-click menu, the Load dialog appears, asking you to select either the Default configuration or one you have set up as an alternative.