User`s guide

Examples of C MEX-File S-Function Blocks

3-61

Example - Discrete State S-Function

The matlabroot/simulink/src/dsfunc.c example shows how to model a

discretesystemin a C MEX S-function.Discretesystems can bemodeled bythe

following set of equations:

dsfunc.c implements a discrete state-space equation. The output portion is

placed in

mdlOutputs and the update portion in mdlUpdate. To visualize how

the simulation works, refer to the flowchart on page 3-16. The output equation

above corresponds to the

mdlOutputs in the major time step. The update

equation above corresponds to the

mdlUpdate in the major time step. If your

model does not contain continuous elements, the integration phase is skipped

and time is moved forward to the next discrete sample hit.

(output)

(update)

u,,()=

d1+

u,,()=

(states)

(input) (output)