User`s guide

Model Execution

6-19

• MdlTerminate(void) — MdlTerminate contains any block shutdown code.

MdlTerminate is called by the run-time interface, as part of the termination

of the real-time program.

The contents of the above functions are directly related to the blocks in your

model. A Simulink block can be generalized to the following set of equations:

Output, y, is a function of continuous state, x

, discrete state, x

,andinput,u.

Each block writes its specific equation in the appropriate section of

MdlOutput.

The discrete states, x

, are a function of the current state and input. Each block

that has a discrete state updates its state in

MdlUpdate.

The derivatives, x, are a function of the current input. Each block that has

continuous states provides its derivatives to the solver (e.g.,

ode5)in

MdlDerivatives. The derivatives are used by the solver to integrate the

continuous state to produce the next value.

The output, y, is generally written to the block I/O structure. Root-level

Outport blocks write to the external outputs structure. The continuous and

discrete states are stored in the states structure. The input, u, can originate

from another block’s output, which is located in the block I/O structure, an

external input (located in the external inputs structure), or a state. These

structures are defined in the

model.h file that the Real-Time Workshop

generates.

tx,

u,,()=

d1+

tx,

u,()=

u,,()=