What does the ssSetChecksumVal function do in Real-Time Workshop 6.2 (R14SP2)?

I generated code from my model using Real-Time Workshop and the S-function target. I noticed that there is a call to the ssSetChecksumVal function, but I could not find any documentation about this function.

Answer 1

[MathWorks Support Team]

This change has been incorporated into the documentation in Release 14 Service Pack 3 (R14SP3). For previous releases, read below for any additional information:

We have verified that the Real-Time Workshop documentation does not provide information on the ssSetChecksumVal function. Some information about this function is provided here:

Checksums are created for each system in a Simulink model by combining all of the properties (e.g., data type, complexity, sample time, port dimensions, etc.) associated with each block in the system. Then, a checksum for the entire model is determined by combining the checksums for all systems with other model-level information. The ssSetChecksumVal function allows an S-function to add more information to the checksum that might not be captured based on block properties.

The checksums are used for various features in Simulink, such as:

• Code reuse - When two systems have the same checksum, Real-Time Workshop generates code for a function only once.
• Model reference - When the current model checksum matches the checksum at build time, Real-Time Workshop does not rebuild submodels.
• External mode - If the current model checksum does not match the checksum of the code that is running on the target, an error is generated.

For the S-function target, the value that Real-Time Workshop adds to the checksum is the checksum of the model or system for which the S-function was generated.