This is machine translation

Translated by Microsoft
Mouseover text to see original. Click the button below to return to the English verison of the page.

Note: This page has been translated by MathWorks. Please click here
To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.

Simulink Debugger

Use Simulink® debugger to trace problems in your model to specific blocks, parameters, or interconnections

The Simulink debugger allows you to run a simulation one method at a time, and examine the results of executing each method. As the model simulates, you can display information on block states, block inputs and outputs, and block method execution within the Simulink Editor. This allows you to pinpoint problems in your model to specific blocks, parameters, or interconnections.

Use the Simulink debugger to:

  • Monitor single block dynamics (for example, output and update) during a single major time step.

  • Look at state of system while executing a major time step.

  • Observe solver dynamics during a single major step.

Simulink also supports debugging with the Simulation Stepper, which lets you step back and forth through your simulation, viewing data and inspecting how and when the system changes states. For information, see How Simulation Stepper Helps With Model Analysis.


sldebug Start simulation in debug mode

Simulink Debugger Commands

ashow Show algebraic loop
atrace Set algebraic loop trace level
bafter Insert breakpoint after specified method
break Insert breakpoint before specified method
bshow Show specified block
clear Clear breakpoints from model
continue Continue simulation
disp Display block's I/O when simulation stops
ebreak Enable (or disable) breakpoint on solver errors
elist List simulation methods in order in which they are executed during simulation
emode Toggle model execution between accelerated and normal mode
etrace Enable or disable method tracing
help Display help for debugger commands
nanbreak Set or clear nonfinite value break mode
next Advance simulation to start of next method at current level in model's execution list
probe I/O and state data for blocks
quit Stop simulation debugger
rbreak Break simulation before solver reset
run Run simulation to completion
slist Sorted list of model blocks
states Current state values
status Debugging options in effect
step Advance simulation by one or more methods
stimes Model sample times
stop Stop simulation
strace Set solver trace level
systems List nonvirtual systems of model
tbreak Set or clear time breakpoint
trace Display block's I/O each time block executes
undisp Remove block from debugger's list of display points
untrace Remove block from debugger's list of trace points
where Display current location of simulation in simulation loop
xbreak Break when debugger encounters step-size-limiting state
zcbreak Toggle breaking at nonsampled zero-crossing events
zclist List blocks containing nonsampled zero crossings

Examples and How To

Start the Simulink Debugger

How to start a simulation from the debugger.

Start a Simulation

How to start a simulation in debug mode.

Run a Simulation Step by Step

How to run a simulation step by step.

Set Breakpoints

How to set breakpoints at blocks and time steps.

Display Information About the Simulation

How to display information about the current simulation.

Display Information About the Model

How to display information about the model being debugged.

Run Accelerator Mode with the Simulink Debugger

How to use the Accelerator mode with the debugger


Introduction to the Debugger

Overview of the debugger.

Debugger Graphical User Interface

How to use the debugger graphical user interface.

Debugger Command-Line Interface

How to debug from the MATLAB® command line.

Debugger Online Help

How to get help on debugger commands.

Related Information

Was this topic helpful?