Run a Simulation Step by Step
The Simulink® debugger provides functions you can use to advance a simulation from the method where it is currently paused by various increments. For example, you can advance the simulation:
Into or over the next method
Out of the current method
To the top of the simulation loop
After each advance, the debugger displays information that enables you to determine the point to which the simulation has advanced and the results of advancing the simulation to that point.
For example, after each step command, the debugger highlights the current method call stack in the Simulation Loop pane. The call stack comprises the next method and the methods that invoked the next method directly or indirectly.
When you debug simulations programmatically, use the
where function to display the method call stack.
Block Data Output
After executing a block method, the debugger prints some or all of the following block data in the Output panel:
Un = v— nth block input value
Yn = v— nth block output value
CSTATE = v— Block continuous state vector
DSTATE = v— Block discrete state vector
The debugger also displays the current time, the ID and name of the next method to be executed, and the name of the block to which the method applies in the MATLAB® Command Window. The following example illustrates typical Simulink debugger outputs after a step command.
When you debug a model programmatically, use these commands to advance a simulation incrementally.
Steps into the next method, stopping at the first method in the next method or, if the next method does not contain any methods, at the end of the next method
Steps to the method that follows the next method, executing all methods invoked directly or indirectly by the next method
Steps to the end of the current method, executing any remaining methods invoked by the current method
Steps to the first method of the next time step
Steps to the next block method to be executed, executing all intervening model- and system-level methods
From the user interface, use the buttons in the toolbar to step through the simulation.
Clicking a button has the same effect as entering the corresponding command.
Continuing a Simulation
When you start the debugger from the Simulink Toolstrip, the Stop button turns red when the debugger
pauses the simulation for any reason. To continue the simulation, click the
Start/Continue button. When you debug a model programmatically,
continue to continue the simulation. By default, the Simulink debugger runs the simulation to the next breakpoint or to the end of the
simulation, whichever comes first.
Running a Simulation Nonstop
run function runs a simulation to the end of the simulation,
skipping any intervening breakpoints. At the end of the simulation, the Simulink debugger returns you to the MATLAB Command Prompt. To continue debugging a model, you must restart the
The user interface does not provide a graphical version of the
command. To run the simulation to the end, clear all breakpoints and then click