Transfer of Fcn Block between Simulink and MATLAB

Hi, everyone. Before simulation I need to transmit to my Simulink model each time different function which is located in Fcn block. Of course I can pass variables to Fcn block but it is not sufficient. Thanks for your help.

Answer 1

[Kaustubha Govind]

If you are using the Fcn block, you can simply change the setting for the "Expression" before each simulation. For example,

   set_param('mymodel/Fcn', 'Expr', 'foo(u(1))')

[Rostyk Spolyak]

Thanks. How can I automate this process? Because I have hundreds of Fcn blocks and all of them use the same function.

[Kaustubha Govind]

You can use find_system to find blocks in your model that have BlockType=Fcn (see http://www.mathworks.com/help/toolbox/simulink/slref/find_system.html).

Here is a relevant blog post: http://blogs.mathworks.com/seth/2008/03/04/searching-in-simulink/

Answer 2

[Rostyk Spolyak]

Thank you for your answers :)

After executing "find_system" command I get a list with names of all Fcn blocks in my model. So, how can I change the 'Expression' in all blocks? I tried using "set_param" function but It works only with a models. Any idea?

[Kaustubha Govind]

Rostyk: set_param works with models AND blocks. See my answer for how I specify the full path to the block to set the parameter.

[Rostyk Spolyak]

I suppose you dont understand my question.

Input argument for function 'set_param' must be the model or block. 'find_system' returns handles or paths to the objects.

I have nearly 50 Fcn blocks. So after executing find_system I get a list of all Fcn blocks. Then I must type 50 commands like this:

set_param('mymodel/Fcn1', 'Expression', 'u*128+5')

set_param('mymodel/Fcn2', 'Expression', 'u*128+5')

...

set_param('mymodel/Fcn50', 'Expression', 'u*128+5')

It is very boring to type everytime 50 commands. So I want to automate this process. I think I can make a script where I will write all this 50 commands and execute it everytime I need. Is there any other possibility? Maybe 'set_param' can receive as an object handle or vector of path to the objects?

Thanks for your help.

[Kaustubha Govind]

set_param cannot handle a cell array of block paths (although get_param can). But it's fairly trivial to loop through the array:

bh = find_system('mymodel', 'BlockType', 'Fcn');

for i = 1:numel(bh), set_param(bh{i}, 'Expression', 'u*128+5'), end

[Rostyk Spolyak]

Thanks. I`ll try this.