[Simulink] Subsystems are locked and the parameters cannot be changed.

Hi,

I have a problem in Simulink model.

I put several same subsystems in one model (for example, named 'SS1' and 'SS2'), and I tried to change a parameter ('param') in the subsystems.

I wanted to set DIFFERENT value in each subsystem, SS1 and SS2, so wrote a code by using "set_param" command like this :

• set_param('…SS1/param', 'Value', '1')
• set_param('…SS2/param', 'Value', '2')

The paramter in SS1 can be set, but the command for SS2 generates an error like this :

• "SS2 is locked by SS1, so the parameter in SS2 cannot be changed."

How can I avoid this problem?

Best,

Answer 1

[Riya]

Hi,

I understand that you are encountering an error while trying to assign different parameter values to two subsystem instances (“SS1” and “SS2”).

I tried reproducing the issue using both independent and dependent subsystems and it worked fine on my end.

Possible reasons for the error could be:

• You might be trying to modify the blocks or connections in a way that changes the overall structure of the subsystem.
• The subsystem could be masked or protected which limits the ability to make certain changes to it.

As a workaround, you can consider the following approaches:

• Breaking the library links if not needed, using the following code:

set_param('myModel/SS1', 'LinkStatus', 'none'); 
set_param('myModel/SS2', 'LinkStatus', 'none'); 

• Or, you can use Variant subsystems to allow instance-specific configurations.

For more details, refer the following documentation:

Variant Subsystems: https://www.mathworks.com/help/releases/R2021a/simulink/ug/variant-subsystems.html?searchHighlight=variant%20subsystems&searchResultIndex=2

Break Links to library blocks:

https://www.mathworks.com/help/releases/R2021a/simulink/ug/disable-links-to-library-blocks.html