Matlab Simulink with Stateflow chart not outputting in scope with warning

Question

I have a Simulink model with a Stateflow chart with an outflow scope to output array/vector variables into. I am using the latest version of Matlab 2013a. This may have something to do with this warning when I run the simulation:

Warning: The model 'xxx' does not have continuous states, hence
Simulink is using the solver 'FixedStepDiscrete' instead of solver
'ode3'. You can disable this diagnostic by explicitly specifying a
discrete solver in the solver tab of the Configuration Parameters
dialog, or by setting the 'Automatic solver parameter selection'
diagnostic to 'none' in the Diagnostics tab of the Configuration
Parameters dialog 

I have looked for these options within Simulink to set the 'Automatic solver parameter selection' diagnostic to 'none'. Can someone help me the find Simulink detailedmenu navigation to resolve this? Thanks

Answer 1

You need to select an appropriate solver. To do this, right click on an empty area in the model, and select Configuration Parameters. The solver settings are listed in the Solver entry in the left pane.

From the warning, it looks like you currently have a variable-step ode3 solver selected. However, none of the blocks in your model support continuous states, so Simulink is instead defaulting back to a fixed step discrete solver.

Set the Type to Fixed-step, and Solver to Discrete; the warning should go away. If you do want the have a variable-step solver eventually, then maybe you should just ignore the warning for now, until you've added blocks supporting continuous states to the model, which will prevent Simulink from automatically switching solvers.

The other option is to disable the diagnostic that's emitting the warning. This can be done by selecting Diagnostics in the left pane of the Configuration Parameters window.