View Sample Time Information

R2026b

Simulink^® models can display color coding and annotations that represent specific sample times. You can display the blocks and signal lines in color. The annotations are badges on the output ports on the blocks and are colored in black:

1. To enable colors, in the Simulink model window, on the Debug tab, select Information Overlays > Colors.

2. To enable annotations, on the Debug tab, select Information Overlays > Text.

Selecting both Colors and Text displays both the colors and the annotations. Regardless of your choice, Simulink performs an Update Model automatically.

To turn off the colors and annotations:

1. On the Debug tab, select Information Overlays > Colors to disable colors.

2. On the Debug tab, select Information Overlays > Text to disable annotations.

When you change these settings, the software automatically performs Update Diagram.

Your sample time display choices directly control the information that the Timing Legend displays.

Note

The discrete sample times in the table Designations of Sample Time Information represent a special case. Five colors indicate the speed through the fifth fastest discrete rate. A sixth color, orange, represents all rates that are slower than the fifth discrete rate. You can distinguish between these slower rates by looking at the annotations on their respective signal lines.

Inspect Sample Time Using Timing Legend

You can view the Timing Legend for an individual model or for multiple models. Additionally, you can prevent the legend from automatically opening when you select options on the Sample Time menu.

To assist you with interpreting a block diagram, the Timing Legend contains the sample time color, annotation, and value for each sample time in the model. To view the legend:

1. In the Simulink model window, on the Modeling tab, click Update Model.

2. On the Debug tab, select Information Overlays > Legend, or press Ctrl+J.

   You can also use the shortcut on the Explorer Bar on the left side of the Simulink Editor.

Three colors indicate the three fastest discrete sample times. The third color, blue, represents all rates that are slower than the third discrete sample time. The sample time colors can be customized to have more colors for discrete sample times.

In addition, when you select Colors or Text, the software updates the model diagram and opens the legend by default. The legend contents reflect your choices. If you turn colors on, the legend displays the color and the value of the sample time. If you turn annotations on, the annotations appear in the legend.

The legend displays sample times present in the model, classified by the type of the sample time. To avoid clutter, the timing information is displayed in rows that expand to show more information about each specific sample time. You can expand each row to learn how that specific sample time is introduced in the model. Check boxes for sample times also allow you to choose specific sample times to display. The Timing Legend also displays the base rate and scalar multipliers for analysis of the discrete time-lines.

For discrete sample time, the Time/Freq toggle button allows you to choose the format of the multiplier information. All discrete sample times are combined into the same row, for example, periodic partitions, discrete export function etc. Triggered sample time rates are now visualized as their source sample times, illustrating the sample rate that drives the trigger. Annotations for aperiodic partition, reset, initialize, reinitialize, and terminate sample times do not use their event names as annotations but instead have their own concise annotations.

The Timing Legend allows you to highlight the blocks and signals in the model that the sample time originates from. Expand a sample time row, and then click the hyperlink to navigate to the block in the model.

Note

The Timing Legend displays all of the sample times in the model, including those that are not associated with any block. For example, if the fixed step size is 0.1 and all blocks have a sample time of 0.2, then both sample times (0.1 and 0.2) appear in the legend.

You do not need to update your model when you change the sample time visualization options or when you open the Timing Legend after compiling the model. (since R2023b)

If you do not want to view the legend upon selecting Sample Time Display:

1. In the Simulink Toolstrip, on the Modeling tab, select Environment > Simulink Settings.

2. In the General pane, clear Open the timing legend when the sample time display is changed and click Apply.

Sample Time Visualization Across Model Hierarchies

When working with model reference hierarchies, Simulink provides hierarchy-synchronized sample time visualization. This synchronization ensures that sample time colors, annotations, and Timing Legend information remain consistent across the entire model hierarchy, so you can interpret timing behavior without reconfiguring each referenced model individually.

Top Model Determines Visualization

The top model mDiscrete defines the sample time visualization for the entire hierarchy. When you toggle the Colors, Text, or Timing Legend in any model window, Simulink updates the top model's visualization settings and automatically refreshes the entire hierarchy. This ensures that a single, consistent timing context is used when inspecting rate behavior across model boundaries.

As shown below, the sample time colors, annotations, and rate labels originate from this model's compiled rates, and the referenced model inherits these visualization settings when opened in the context of the model hierarchy.

Sample Time Mappings

Referenced models may contain explicitly scheduled sample times or inherit sample times from the top model. During compilation, Simulink analyzes sample time mappings between the top and referenced models. These mappings determine how each referenced-model rate corresponds to the top-model rates and ensure that referenced models are displayed using the top model's timing context.

The Timing Legend includes a Display Source widget that indicates whether the displayed sample time colors come from the top model or the referenced model.

A referenced model can be viewed in two ways, depending on how it is opened.

Open in Context.  To open a referenced model in the context of the current model hierarchy, double-click the corresponding Model block. Alternatively, right-click the Model block and select Open in New Tab or Open in New Window.

When opened this way, the referenced model automatically inherits the top model's sample time colors and annotations. The referenced model displays the same colors and rate labels, with rates derived from the top model's base rate. This synchronized view makes it easier to see how the referenced model executes in the context of the full model hierarchy.

Open Outside of Model Hierarchy.  To open a referenced model outside of the current model hierarchy, on the Model block icon, click the Open As Top Model badge. Alternatively, right-click the Model block and select Open as Top Model.

When msamp_basic is opened as a top model, Simulink compiles it independently. Sample time colors and annotations must be toggled explicitly in this new window. The Timing Legend reflects the intrinsic base rate and rate ordering of msamp_basic. In this view, the rate labels and colors no longer map to the timing context of mDiscrete.

When Synchronization Does Not Apply

Synchronized sample time visualization is supported when the software can map the sample times between the top model and referenced models in a meaningful way. When the software cannot map the execution rates, the reference model shows its own timing context. In this case, sample-time colors, annotations, and the timing legend might differ from those in the top model.

In the following example, the top model schedules the referenced model using periodic event ports. The Model block is displayed using the top model's timing context and appears as rate D2.

When you open the referenced model, the software displays the model using its own timing context instead of the top model's. The Display Source widget indicates that the sample time colors, annotations, and Timing Legend are derived from the referenced model.

Customize Sample Time Colors

You can customize sample time color palette using the simulink.sampletimecolors.Palette object and its functions. You can create a customized color palette object for all types of sample times in your model. You can then use this palette for your current MATLAB^® session, or make it a default color palette for all your MATLAB sessions.

Create Custom Sample Time Color Palette to Use as Default

1. Create a custom color palette object with the name myFirstPalette.

   pltObj = simulink.sampletimecolors.Palette("myFirstPalette");

   Palette with properties:
    
                                     Name: "myFirstPalette"
               ContinuousSampleTimeColors: [0 0 0]
         FixedInMinorStepSampleTimeColors: [0.4902 0.4902 0.4902]
       ContinuousVariableSampleTimeColors: [0.4902 0.4902 0.4902]
                 DiscreteSampleTimeColors: [3x3 double]
             AsynchronousSampleTimeColors: [0.7529 0.3608 0.9843]
                 AperiodicPartitionColors: [0.7529 0.3608 0.9843]
          InitializeEventSampleTimeColors: [0.7961 0.5176 0.3647]
           TerminateEventSampleTimeColors: [0.7961 0.5176 0.3647]
               ResetEventSampleTimeColors: [0.7961 0.5176 0.3647]
        ReinitializeEventSampleTimeColors: [0.7961 0.5176 0.3647]
                 ConstantSampleTimeColors: [0.8196 0.0157 0.5451]
                MultirateSampleTimeColors: [0.5451 0.4000 0.0235]
                    UnionSampleTimeColors: [0.4039 0.2980 0.0235]

2. Customize colors for the continuous sample time using RGB values.

   pltObj.ContinuousSampleTimeColors = [0.9 0.2 0.4];

3. Customize colors for discrete sample time. This step shows different ways to set the colors for sample times.

   • Use hexadecimal codes to customize colors.

     pltObj.DiscreteSampleTimeColors = ["#123456", "#523467", "#204973"];

   • Use predefined MATLAB colormaps, for example, parula. For more information, see Change Color Scheme Using a Colormap.

     pltObj.DiscreteSampleTimeColors = parula(3);

     A model with sample time colors set to parula:

     

   • Use the pre-configured built-in classic color palette to customize sample time colors:

     simulink.sampletimecolors.applyPalette("classic (built in)")

     A model with sample time colors set to classic (built in):

     

   • Use the pre-configured built-in color blind color palette to customize sample time colors:

     simulink.sampletimecolors.applyPalette("color blind accessible (built in)")

     A model with sample time colors set to color blind accessible (built in):

     

4. Set the new custom color palette as a default palette for the current and all future MATLAB sessions.

   simulink.sampletimecolors.applyPalette(pltObj,"UserDefault",true)

   To see the new color palette for sample times in your Simulink model, press Ctrl+D to update the model.

Inspect Sample Times Throughout Model

The Model Data Editor shows information about model data such as signals, parameters, and states, in a sortable, searchable table. To open the Model Data Editor, on the Modeling tab, click Model Data Editor. The Sample Time column shows the sample time specified for each signal in a model. After you update the block diagram, the column also shows the specific sample that each signal uses. For example, for signals for which you specify inherited sample time, the column shows -1. You can also use this column to specify sample times.

For more information, see Model Data Editor.