MATLAB: Is it possible to add custom block parameters to Simulink blocks in Simulink 7.8 (R2011b)

get_paramset_paramsimulinkuserdatauserdatapersistent

I would like to add custom parameters to built-in blocks in my Simulink model. For example, if the model, 'myModel' contains the Gain Block, 'gain1' I would like to add a parameter 'myParam' to this block so that I may access it via:

get_param('myModel/gain1', 'myParam')
set_param('myModel/gain1', 'myParam', some_value)

Moreover, I would like for the value of the parameter to persist after I save and close the model's MDL file.

Best Answer

The ability to add custom parameters to built-in blocks is not available in Simulink 7.8 (R2011b). To work around this issue, starting in Simulink 7.8 (R2011b) it is possible to mask built-in blocks which do not already have a mask. This may be done by right-clicking on the block and choosing 'Create Mask'. Within the Mask Editor dialog, block parameters may be added to the block that are accessible via the functions GET_PARAM and SET_PARAM.

In versions before Simulink 7.8 (R2011b), the block parameter 'UserData' may be used to store the desired values. Also, the parameter 'UserDataPersistent' may be set to 'on' in order to save the data stored in 'UserData' in the model file. For example:

set_param('myModel/gain1', 'UserData', myData)
set_param('myModel/gain1', 'UserDataPersistent', 'on')

would save the value 'myData' in 'UserData' and specify that it should be stored in the MDL file after the model is saved and closed.

Related Solutions

MATLAB: Does the ‘UserData’ property for a block not persist across Simulink sessions even though I have the ‘UserDataPersistent’ property set to ‘on’

Any entity that can be saved in a MAT file and then loaded back to the MATLAB workspace will persist when saved in the 'UserData' field for a block.

For example, a .NET object cannot be saved in a MAT file and retrieved later. Hence, if it is attached to the 'UserData' property, it will be lost if the model is closed or Simulink is closed. This is documented in the limitations below:

https://www.mathworks.com/help/matlab/matlab_external/limitations-to-net-support.html

The 'UserData' and 'UserDataPersistent' properties for any block can be set using the 'set_param' command. For example, after selecting a block in a Simulink block diagram, the following commands can be used to set the properties:

>> set_param(gcb,'UserData',5)
>> set_param(gcb,'UserDataPersistent','on')

MATLAB: How to include the Icon data of a Mask in a Library without using any additional files in Simulink 7.3 (R2009a)

This can be done by storing the image data in the Block Parameter 'UserData' function. To implement this, follow the steps below.

1. Store the image in matrix form in the MATLAB workspace.

2. Mask the library block

3. To store the picture variable in the block, execute the following at the MATLAB command prompt:

set_param(gcb,'UserData',<picture variable>)

4. For the data to be stored in the block when it is closed, the 'UserDataPersistent' parameter must be set to 'on', by executing the following at the MATLAB command prompt:

set_param(gcb,'UserDataPersistent','on')

5. In the Initialization tab of the Mask Editor, add the code at the MATLAB command prompt:

pic = get_param(gcb,'UserData');

6. In the Icon & Ports tab of the Mask Editor, add the code

image(pic)

Best Answer

Related Solutions

MATLAB: Does the ‘UserData’ property for a block not persist across Simulink sessions even though I have the ‘UserDataPersistent’ property set to ‘on’

MATLAB: How to include the Icon data of a Mask in a Library without using any additional files in Simulink 7.3 (R2009a)

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