Comments on: Libraries in Simulink

By: Thomas

Thomas — Tue, 09 Aug 2011 10:13:11 +0000

In regards to libraries I cannot find any information regarding the ability to update a version of a model at its source file which then updates the block held within the library file.

Is this possible or do you need to open up the library file every time and copy the updated block in?

thanks!

By: Moreno

Moreno — Wed, 13 Oct 2010 12:39:21 +0000

@Seth,@Zhibo; Thanks for your answer I found another very usefull document concerning Libraries vs Model Reference at “http://www.mathworks.com/programs/cd_mbd/” Large-Scale Modeling for Embedded Applications

By: Seth

Seth — Tue, 12 Oct 2010 17:59:29 +0000

@Zhibo, @Moreno: When you say Libraries vs Model Reference, I interpret your question as when to use SUBSYSTEMS vs Model Reference. Generally, it is an architectural choice. We have seen people take Model Reference to the wrong extreeme, such as, reference models with only 3 blocks in them. This is more appropriately modeled with subsystems. Generally, if you have a plan for your model architecture, you can easily try model reference at certain levels, and decide if it meets your need. If you select a level that is too low in the hierarchy, you end up with the problem I describe above. If you select a level too high in the hierarchy, you don’t get the maximum benefit from Model Reference features (such as incremental workflows, and componetization).

There are existing guidelines that address the use of Model Reference. The one I have most recently looked at is the NASA Orion GN&C Standards. I reccomend you review those, and search for “model reference”:

http://www.mathworks.com/aerospace-defense/standards/nasa.html

Or, go directly to the NASA Orion GN&C Simulink Standards PDF, section 4.4.3 ORION GN&C Model Architecture Decomposition for an example of how they did it.

By: Moreno

Moreno — Tue, 12 Oct 2010 09:08:24 +0000

Dear Zhibo,
Please let me know if you find any guideline/document advising “when to use libraries vs model referencing”.
I’m facing the same issue, what should be used for large collaborative models?

By: Zhibo

Zhibo — Tue, 22 Jun 2010 13:16:31 +0000

I would like to know when to use libraries vs model referencing too. Thanks!

By: Seth

Seth — Fri, 02 Apr 2010 18:55:26 +0000

@Alex - XML is not a part of embedded code generation with Real-Time Workshop. We have documentation that describes how to compare XML files exported from Simulink models. That is a good resource to reference for more information on this capability.

By: Alex

Alex — Fri, 02 Apr 2010 03:57:50 +0000

Seth, I am confused with how XML is being used with Mathworks products. Does there exist the capability to generate embedded code from XML? If so where can I read more about it.

By: Guy

Guy — Mon, 05 Oct 2009 14:20:21 +0000

Patrick,

You are right when you mention that adding a “Mask Description” to a masked subsystem in a library makes it not-expandable.

This is coherent with the behavior of masked subsystems in a model. Typically you mask a subsystem when you think the user should not look inside. If the user should not look inside, then the subsystem should not expand in the Library Browser.

As an additional note, if a masked subsystem have parameters, you do not need to add a “Mask Description” to hide it’s content. For masked subsystems without parameters, it is by adding a “Mask Description” that you force the user to “look under mask” to see its content.

Guy

By: Patrick

Patrick — Fri, 02 Oct 2009 17:27:20 +0000

Guy,

I’ve recently run into a related issue. It would appear that if you create your own masked sub-system and want to include it in a library in an expandable form, you cannot add any “Mask Description”. Including a “Mask type” seems to work fine though. This is using 2007b…haven’t tried anything newer yet.

Patrick

By: Guy

Guy — Tue, 30 Jun 2009 23:14:15 +0000

@Pat and Paul, I agree that the slblocks documentation is unexisting. From what I remember, when subsystems are masked the Library browser does not expand them and you cannot see what is under the mask.

I think the reason for this behaviour is that if you place a block in the library browser you don’t want the user to modify it. If you don’t need to define any parameters for the mask, fill some info in the documentation tab of the mask editor.

I hope it helps.

Guy