Protecting dynamic masked subsystem

Hello, I am working with dynamic masked subsystem. I do not want to distribute my design/algorithm to the third party user. I did a search on the internet and on this forum, and come across 3 methods to protect the subsystems:

1. Control access to subsystem by setting 'NoReadOrWrite' permission on the subsystem. But this setting can be easily reverted by user.

2. Generate S-function for the subsystem. It appears to me that this method is not applicable to masked subsystem. Please correct me if I am wrong.

3. IP protection by creating .mdlp files. I was going through the steps described at http://www.mathworks.com/products/demos/simscape/PhysMod_Demo_IP_Protection/. When I converted my subsystem to model block (by right clicking the subsystem and choosing the option 'convert to model block') an error occurred saying that masked subsystem can not be converted to model.

Am I doing something wrong or there is any other way to protect the masked subsystems. Any pointers on this will bw very helpful.

Thanks Abhishek

Answer 1

[Kaustubha Govind]

You might want to generate a protected model or S-function from an unmasked version of the subsystem, and then create the mask again over the generated, protected version?

[Abhishek]

Hello Kaustubha,

Thanks for your prompt reply. Consider the scenario where the design/algorithm of the subsystem depends on the mask parameters (for eg clicking a checkbox in the mask GUI determines whether input is real or complex). So depending on the mask parameter values I chose one of the many designs/algorithms I have.

For such dynamic subsystem, I don't think I can protect it using S-function approach (correct me if I am wrong). I am not sure whether I can protect my subsystem design using protected model approach. Any pointers on this will be very useful. Also, I understand that I need a 'Simulink Coder' license to generate protected referenced model (.mdlp file).

Thanks

Abhishek

[Kaustubha Govind]

Do you mean a Variant/Configurable subsystem? I'm not sure if model reference blocks support these - they probably inline the variant of the subsystem selected at compile-time. And yes, I believe Simulink Coder is in fact needed to generate protected referenced models.

Answer 2

[Abhishek]

Hello,

I observed that while converting a subsystem to reference block I can inherit the sampling time but I can not inherit the port width. Is there any work around so that I can inherit the port width also.

Thanks Abhishek

[Kaustubha Govind]

I think the port dimensions need to be fixed for referenced models, because code is generated for the underlying model. You could try running the referenced model in "Normal" mode and see if it allows for inherited port dimensions in that mode.