How can I have the To File block use the file name from a workspace variable in Simulink 6.5 (R2006b)?

I have a To File block in my model and I want to use a workspace variable containing a string to specify the file name for this block. The To File block does not accept the name of a workspace variable like the Gain block does.

Answer 1

[MathWorks Support Team]

The To File block does not have the ability to evaluate a workspace variable to get the file name. In this case you can mask the block and call the SET_PARAM function from the mask's initialization callback function. Here are the steps:

1. Select the To File block in your model

2. In the Command Window enter

set_param(gcb,'Mask','on');

3. Right-click the block and choose "Edit mask" from the context menu.

4. On the Parameters pane in the Mask Editor add a parameter to store the file name entered by the user

5. On the Initialization pane add a call to SET_PARAM to set the To File block's filename property:

set_param(gcb,'Filename',fn);

6. You can now enter the filename as string into the block mask or you can enter the name of a variable which is then evaluated

Please find attached an example model. The steps mentioned above could also be used for the following blocks:

- To Workspace

- From Workspace

- To File

- From File

[Jeff]

Hi, the above approach (following the mask_example.mdl) doesn't work for the 'From File' block in R2013a, i get the error:

Invalid setting in FromFile block 'From File' for parameter 'FileName'

any other solutions ?

thanks, /jeff

[Kaustubha Govind]

Jeff: What is the value that you enter for the 'fn' parameter on the mask dialog?

[Kristia Harris]

I seem to be having the same problem with the "From File" block. I have the prompt and variable set as "Filename" and "Input_Filename" under the Parameters tab. The initialization command is set as set_param(gcb,'Filename',Input_Filename); In the Workspace, the Input_Filename = 'code.m'

Any ideas here?

Thanks,

Kris

Answer 2

[Marc Compere]

Nice. Using a mask to evaluate the filename is clever.

mask_example.mdl worked correctly with no modifications in R2014a.

I've attached a modified version that sets the filename to the computer's current date and time. This creates a (probably) unique filename each time the simulink model is started. As long as you don't press start more than once a second it'll create a filename with DD.MMM.YYYY.HH.MM.SS in the filename. This is handy for collecting data during testing.

I would upload the .slx directly but the uploader won't accept it. zipfile attached.