Simulink: create struct with signal names

Hello,

after the Simulink simulation I would like to have a structure that contains certain signal values. The simples way to do this is to mux all signals together and write them with the block "To Workspace". But here I loose the information about the signal names. Is there an solution to create a structure that contains all signal names? I thought the structure could look like this:

data.time = ...
data.speed = ...
data.dist = ...

Cheers, Frank

Answer 1

[TAB]

Do you want the output values at each time step or just final simulation value ?.

You can feed your bus output to a embedded matlab block. This bus object will appear as structure in embedded matlab block. In the block function you can write matlab code to save structure to workspace. For example

function fcn(Data)
eml.extrinsic('assignin');
assignin('base','MySavedData',Data);

To use buses in Embedded matlab function, bus objects must be defined in base workspace.

See Working with Structures and Bus Signals

[Edited]

I think this can fullfil your need. Use data logging feature of simulink.

Goto Configuration Parameters -> Data Import/Export -> Check "Signal logging" -> Define any variable name say "LoggedData"

Right Click on Output bus -> set the prorerties as shown in image. Keep Show Propagated singals->on

After running the model a variable "LoggedData" will be created on workspace.

You can acsess you data as

LoggedData.BusOut.a.Data
LoggedData.BusOut.a.Time

and

LoggedData.BusOut.a1.Data 
LoggedData.BusOut.a1.Time

[Frank]

I want the output values for each timestamp.

I created a bus object 'MySavedData', but when your code is executed the bux object is overwritten with a struct with the same name.

[TAB]

See My Edited answer.

[Frank]

Hey thanks for your answer. Is it possible to extend your first approach? Because with in the embedded matlab function I can determine the name of the block/model where the function is running. By this means I could dynamically choose the variable name to store all the values in.

E.g. when I reuse my "logging"-block in multiple models then the data would be written in different variables.

[TAB]

You can access the model name in Embedded matlab block using command 'bdroot' and can use this name as variable name to save data.

function fcn(Data)

eml.extrinsic('assignin');

eml.extrinsic('strcat');

eml.extrinsic('bdroot');

VarName=strcat(bdroot,'_Log');

assignin('base',VarName,Data);

end

But note that, you can not use this Embedded matlab block in code generation. Becuase extrinsic matlab functions do not support code generation.

You can use it for simulation.

[Frank]

Thanks for that. Two more things:

Is there a way to write the whole history of Data into the variable?

How can I write the vector into a structure? e.g. Data.a

Cheers,

Frank.