You can isolate the verification logic in a model by using Observer Reference blocks. Use Observer Reference blocks when you want to keep the verification logic separate from your design model. When you use an Observer Reference (Simulink Test), you can make changes to the Observer model without changing the design model. Using Observer Reference blocks can help you specify properties or requirements early in the model design or across multiple model designs. The Observer Reference block also allows you to:
Model design requirements as properties and prove them using Simulink® Design Verifier™.
Establish baseline results based on the captured output and detect model regressions.
Generate test cases for functional design requirements using custom test objectives.
Double-click an Observer Reference block to open the Observer model. Observer Reference blocks can only be at the top level of a system model and do not have input ports. For more information, see Access Model Data Wirelessly by Using Observers (Simulink Test).
When authoring custom verification objectives, the Observer Reference block can be used in place of the Verification Subsystem block. The Observer Reference block references a separate verification model called the Observer model that you use to verify your system model. Converting a Verification Subsystem block to an Observer Reference block can declutter a system model. To convert a Verification Subsystem block to an Observer Reference block, right-click the verification subsystem and select Observers > Move selected block to Observer > New Observer. This operation cannot be undone. This action adds an Observer Reference block to your system model and opens the Observer model. You must save the Observer model in a writable folder on the MATLAB® path.
Consider the case where the model
contains the Verification Subsystem block
By converting the subsystem to an Observer Reference block, you remove the signals that connect subsystem to the system model while preserving the ability to test the integrity of the system.
The two signals,
automatically mapped to two Observer Port blocks in the Observer
You can verify the properties of
without making any changes to the design model.
If your model includes an Observer Reference block, the Simulink Design Verifier analysis report shows the property proving, test case generation, and design error information for the Observer Reference blocks in the Observer Model(s) subsection and the design model information in the Design Model subsection. For more information, see Simulink Design Verifier Reports.
Simulink Design Verifier does not support:
Observer models that include Model blocks
Applying block replacement rules to Observer models
Observer models that run at a different base rate than the design model
Tuning the parameters inside an Observer model
Test generation for code generated by Embedded Coder® for models that contain Observer Reference blocks
Observer model that uses variable-step solver settings to execute the analysis
If an Observer model includes any of the restrictions in this list, the software ignores the corresponding Observer Reference block during the analysis.
Simulink Design Verifier analysis returns an error when you:
Analyze standalone Observer models
Perform subsystem extraction on an Observer Reference block
Observer Port (Simulink Test) | Observer Reference (Simulink Test) | Use Observer Reference Blocks for Property Proving Analysis | Use Observer Reference Block for Test Case Generation