Hello @AKHILA
The distinction between the “C Function block” and the “S-Function block” in Simulink can be clarified by examining their capabilities and intended use cases:
C Function Block
- Purpose: The C Function block is intended for embedding custom C code into a Simulink model. It is generally used for straightforward computations and invoking external C functions.
- Initialization: It allows for the initialization of persistent data, enabling data to maintain its value across function calls.
- Limitations: The block does not allow for updating persistent data during simulation, meaning you cannot have persistent states that evolve over time within the block.
- Use Case: Best suited for static computations or functions that do not need state updates.
S-Function Block
- Purpose: The S-Function block is highly versatile and robust, enabling the creation of custom blocks that can manage complex behaviors, including dynamic systems with states.
- Initialization and Termination: It allows for both the initialization and termination of persistent data.
- State Updates: In contrast to the C Function block, the S-Function block can handle both continuous and discrete states, making it ideal for modelling dynamic systems.
- Use Case: Perfect for modelling intricate dynamic systems that necessitate state updates throughout the simulation.
Example Scenario
- C Function Block Example: Imagine you have a C-written mathematical function that computes the square root of a number. The C Function block can be used to call this function within a Simulink model. The computation is static, with no need for state updates.
- S-Function Block Example: Consider simulating a simple harmonic oscillator, a system with continuous states (position and velocity) that evolve over time. An S-Function block would be used to implement the differential equations that describe the oscillator's motion, as it supports state updates during the simulation.
To check “C-Function Block” and “S-Function Block” working in MATLAB R2024a please refer this MathWorks Documentation
C-Function Block: https://www.mathworks.com/help/simulink/integrate-external-c-algorithms-using-c-function-block.html
I hope this will be helpful.
