How to read To Workspace block signal value to App Designer ?

Hi Everyone

I know I am asking the question for which answer exists somewhere , but I am new to app designer and I have simple requirement.

In mymodel.slx has "To Workspace1" output block.

In GUI callback to read model output , I am reading using get_param.

Signal1 = get_param('mymodel.slx/To Workspace1','VariableName');

As Signal1 is timeseries data. I want to extract last value to use further.

valueout1 = Signal1.Data(end,:); % Reads the value as last timestamp

At above line I am getting error as "Struct contents reference from a non-struct array object."

In command window code line valueout1 = Signal1.Data(end,:);

works as expected.

valueout1 is expected to get numeric value from 0-9. which I will use in switch case to displa\y some string in Text Box.

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Request your inputs . I am trying to get simplest way to read model output and use it to display on App designer GUI.

Answer 1

[Fangjun Jiang]

Likely it is caused by this

Signal1 = get_param('mymodel.slx/To Workspace1','VariableName') gives you a char array containing the variable name, like

Signal1='MyOutput'.

In the base workspace, variable named 'MyOutput' does exist but you need to do

MyVariable=evalin('base',Signal1);

Then you can do, MyVariable.Data(end,:)

[AK]

Thanks a lot . It worked perfectly.

[AK]

MyVariable.Data(end,:) worked with finite simulation time.

I need to read the value in runtime. When I call the MyVariable.Data(end,:)..it is not giving me runtime value.

Is TimeSeries data correct option for To Workspace1 block ?

I mean

Signal1 = get_param('mymodel.slx/To Workspace1','VariableName')

To Workspace1- is updated countinuosly with time. I have callback when to read updated value. With MyVariable.Data(end,:) i could get only one value and not updated value.

In short now question is rephrased to how to read simout value at current time stamp ?

[Fangjun Jiang]

To Workspace data is written when the simulation is finished. To do what you want, see Block Run-Time Objects

https://www.mathworks.com/help/simulink/ug/accessing-block-data-during-simulation.html

[AK]

I was also exploring on same thing..I will take this approach. Thanks for your response.