Simulink mask: show/hide the port of a custom Simulink block

Hi guys,

I am creating a mask for my custom block and I want add a checkbox with the following behaviour:

• checked: it shows a new port the the block
• unhecked: it hides the new port for the block

The integrator block has the same behaviour (see the belows images to understand):

I am struggling how to implement this feature in the Checkbox callback because I can't find the parameter to show/hide the port.

Answer 1

[SACHIN KHANDELWAL]

Hi @federico ciresola,

I understand that you want to create a block mask with the help of a checkbox. Here are some possible steps that might be helpful to you:

1. Open Simulink and add a Subsystem block.
2. Select Mask > Create Mask.
3. Add a Checkbox and other properties that you want.
4. Add the callback for the Checkbox.

After creating the callbacks, you can simply get the current callbacks using the following command:

>> maskObj = Simulink.Mask.get(gcb);

After you have the mask object, you can modify it based on your needs.

The following documentation could be helpful for you to design the mask:

https://www.mathworks.com/help/simulink/ug/control-masks-programmatically.html

Hope the above information is helpful!

[federico ciresola]

thank you for you answer, I alread have did them. My problem is find a way to show or hide some inputs port from a checkbox such as the integrator block.

I have found this guide https://blogs.mathworks.com/simulink/2008/08/21/mask-initialization-and-self-modifying-blocks/#like but it is too much old and doesn't work

Answer 2

[Aurélien]

Hi @federico ciresola,

Here is an example of how to re-create the Integrator block behavior on a Mask. The initial condition parameter value is used in a Constant block inside the masked subsystem.

It's important to use the initialization() function instead of a callback and to check the box below:

So you can create a custom library of your block without links issues.

If you want to give a name to that Constant block, replace all three gcb with gcb + "/block_custom_name" in the code below:

% Initialization code section
function initialization()
    checkboxValue = get_param(gcbh, 'checkbox');

    maskObj = Simulink.Mask.get(gcbh);
    initParam = maskObj.getParameter('initial_condition_parameter');

    if checkboxValue == "on"
        % Replace constant block with inport block
        replace_block(gcb, "Constant", "Inport", "noprompt");
        
        initParam.Visible = "off"; % Hide parameter
    else
        % Replace inport block with constant block
        replace_block(gcb, "Inport", "Constant", "noprompt");
        set_param(gcb, "Value", "initial_condition_parameter", ...
        "SampleTime", "-1"); % Give block properties back
        
        initParam.Visible = "on"; % Show parameter
    end
end

% Parameter callback section

Hope it helps :)