Max step size

Specify the largest time step that the solver can take.

Category:Solver

Default:auto

For the discrete solver, the default value (auto) is the model's shortest sample time.
For continuous solvers, the default value (auto) is determined from the start and stop times. If the stop time equals the start time or isinf, Simulink^®chooses0.2seconds as the maximum step size. Otherwise, it sets the maximum step size to

$h_{\max} = \frac{t_{s t o p} - t_{s t a r t}}{50}$
ForSineandSignal Generatorsource blocks, Simulink calculates the max step size using this heuristic:

$h_{\max} = \min (\frac{t_{s t o p} - t_{s t a r t}}{50}, (\frac{1}{3}) (\frac{1}{F r e q_{\max}}))$

where $F r e q_{\max}$ is the maximum frequency (Hz) of these blocks in the model.

Generally, the default maximum step size is sufficient. If you are concerned about the solver missing significant behavior, change the parameter to prevent the solver from taking too large a step.
Max step size determines the step size of the variable-step solver.
If the time span of the simulation is very long, the default step size might be too large for the solver to find the solution.
If your model contains periodic or nearly periodic behavior and you know the period, set the maximum step size to some fraction (such as 1/4) of that period.
In general, for more output points, change the refine factor, not the maximum step size.