Sinulink S-function block blank parameter error-MATLAB2011b

Hello,

I am using a user defined S-function Simulink block. I have two parameters inside it: 'DesignName' and 'DesignPath'. Both parameters are blank at the start of the application.

At some point I try to use "set_param" to set values to these parameters. I receive the following error:

" Parameter 'DesignName' setting: "" cannot be evaluated. Error: This statement is incomplete."

However, although I receive this error the correct value is still set.

The error causes my application not to work. When I run the same code on 2011a I do not receive this error and my application completes successfully.

I see the same phenomena when I try to set these parameters with the values manually, using the Simulink GUI.

Are you familiar with such a problem?

Thank you in advance,

Gilad

[Kaustubha Govind]

Could you show us the exact set_param statement that you use to set the parameter? Typically, set_param causes the value to be set on the block even if there is an error (although simulation will not proceed because of the error).

[Gilad]

Thank you for your answer.

As I wrote I see that the value is set, but the error causes my application not to work, as it it wrapped inside a try and catch statement. I don't this the command is relevant as I see the same error when I try to change the values using the Simulink GUI. In addition, the same code works in 2011a. However, since you have asked for the line, here it is:

set_param([modelName '/' modelName '_HW_block'], 'DesignName', ['''' modelName '''']);

Answer 1

[Kaustubha Govind]

Could you try changing that to:

   set_param([modelName '/' modelName '_HW_block'], 'DesignName', modelName);

You shouldn't need to put single quotes around a variable that is already a string. You only need that if you're doing something like:

   set_param([modelName '/' modelName '_HW_block'], 'DesignName', 'mymodel');

It is possible that SET_PARAM was made more robust to the extra apostrophes in R2011a.

[Gilad]

Thank you for your answer.

I have tried it but it still does not work.

[Kaustubha Govind]

Strange - can you reproduce this outside of your application? That is, open the corresponding model, and perform the set_param command? What is the value of modelName?

[Gilad]

Yes, I can. When I open the "S-Function" block I see that both parameters are empty. When I try to set a value to one of them I see the same error:

" Parameter 'DesignName' setting: "" cannot be evaluated. Error: This statement is incomplete."

[Kaustubha Govind]

Do you mean that you're setting the value of the "S-function parameters" dialog box? I don't think the S-function block has a parameter called DesignName.

[Gilad]

"DesignName" is a field that was added to the block by my application.

Maybe "S-Function" this is not the name of the block. The name I see when I open it is:

"S-Function (mask)". Maybe it is a user-defined block (I do not have the correct information as I did not create it nor am I not the programmer of the application). I will try to find the exact name of the block and write it down here.

The thing is that when I do it with MATLAB 2011a it works well- I only receive this error with MATALB2011b

[Kaustubha Govind]

So, just to be clear, you do something like:

set_param('path/to/S-Function', 'DesignName', 'somevalue')

Is this correct?

[Gilad]

Yes, you are correct, this is what I do. I was advised by my local distributor to set a dfault value to the block. I will try it. I still think that there is a small change between the newest version and the previous one, but it does not seem to be important should this workaround work.

Thank you for your efforts,

Gilad

[Kaustubha Govind]

Okay, great! Hopefully your distributor's advice will help. I'm thinking that I don't see the full picture because of how the mask on your S-function is handling the value - there might be some callback code on the mask that is run every time a set_param is performed.

[Gilad]

I think you don't see the full picture because I myself do not fully understand this block. Anyway, the default suggestion solved our issue: now MATALB 2011b does not produce the error.

Thank you very much for all your efforts and time spent.

Gilad