Disallow inheritance of Inf sample time


Prohibits the S-Function block that references this S-function from inheriting a sample time of Inf. The SS_OPTION_DISALLOW_CONSTANT_SAMPLE_TIME option applies only to S-functions that use block-based sample times.


If you have Simulink® Coder™, and the S-function declares the number of sample times as PORT_BASED_SAMPLE_TIMES, it will not inherit a sample time of Inf unless it specifies the SS_OPTION_ALLOW_CONSTANT_PORT_SAMPLE_TIME option.

If you have Simulink Coder, note:

  • If the S-function specifies this option and inherits a sample time of Inf, the Simulink Coder product determines how to generate code for the block based on if the block is invariant.

  • A block is invariant if all of its ports' signals are invariant. A signal is invariant if it has a constant value during the entire simulation. A constant block sample time does not guarantee all the ports' signals are invariant. For more information, see Inline Invariant Signals (Simulink Coder).

  • If the block is not invariant, the Simulink Coder product generates code only in the model_initialize function. If the block is invariant, the Simulink Coder product eliminates the block’s code altogether.


See sfix_fir.cpp for an example.

Introduced in R2007b

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