Floating Scope and Scope Viewer

Display signals generated during simulation without signal lines

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  • Scope Viewer block

Libraries:
Simulink / Sinks
HDL Coder / Sinks

Description

The Simulink® Scope Viewer and Floating Scope blocks display time domain signals with respect to simulation time. The Scope Viewer and Floating Scope blocks have the same functionality as the Scope block, but they are not connected to signal lines.

Scope Tab

The scope display has these capabilities:

  • Simulation control — Run and debug models from a Scope window using the Run, Step Forward, and Step Backward buttons.

  • Multiple signals — Plot multiple signals on the same display.

  • Multiple displays — Display signals on multiple subplots. All the y-axes of the subplots have a common time range on the x-axis. Control the layout of the subplots using the Display Grid parameter in the Scope tab.

  • Modify parameters — Modify scope parameter values before and during a simulation.

  • Axis autoscaling — Autoscale axes during or at the end of a simulation. Margins are drawn at the top and bottom of the axes.

  • Display data after simulation — Save scope data during a simulation. If a scope is closed at the start of a simulation, then when you open the scope after a simulation, the scope displays simulation results for attached input signals.

    Note

    If you have a high sample rate or long simulation time, you might experience issues with memory or system performance because the scope saves data internally. To limit the amount of data saved for scope visualization, select the Limit data points to last parameter.

  • Scope window management –– Use the new scope container to dock multiple scope windows into a single window and to manage and organize the scopes. The scope container also enables you to view all the scopes in the model in a single window.

Measurements Tab

The Scope Viewer and Floating Scope blocks support these measurements:

  • Triggers — Set triggers on repeating signals and pause the display when events occur.

  • Cursor Measurements — Measure signal values using vertical and horizontal cursors.

  • Signal Statistics — Display the maximum, minimum, peak-to-peak difference, mean, median, and RMS values of a selected signal.

  • Peak Finder — Find maxima, showing the x-axis values at which the maxima occur.

  • Bilevel Measurements — Measure transitions, overshoots, undershoots, and cycles.

Note

You must have a Simscape™ or DSP System Toolbox™ license to use the Peak Finder, Bilevel Measurements, and Signal Statistics.

Programmatic Control

Configure and display the scope settings from the command line with the TimeScopeConfiguration object. For an example that shows how to control the scope programmatically, see Control Scope Blocks Programmatically.

Connecting Signals

In the Floating Scope window or Scope viewer window, use the signal connector icon - three blue dashes with a chain symbol button to connect signals.

To add a viewer with a connected signal, select a signal in the model. Then, on the Simulation tab, in the Prepare gallery, click Add Viewer.

For more details, see Add Signals to Existing Floating Scope or Scope Viewer.

Key Features

  • Multiple y-axes (displays) — Display multiple y-axes. All the y-axes have a common time range on the x-axis.

  • Multiple signals — Show multiple signals on the same y-axis (display).

  • Modify parameters — Modify scope parameter values before and during a simulation.

  • Display data after simulation — If a scope is closed at the start of a simulation, scope data is still written to the scope during the simulation. If you open the scope after a simulation, the scope displays simulation results for input signals.

Examples

Simulation of Bouncing Ball

Simulation of Bouncing Ball

Uses two models of a bouncing ball to show different approaches to modeling hybrid dynamic systems with Zeno behavior. Zeno behavior is informally characterized by an infinite number of events occurring in a finite time interval for certain hybrid systems. As the ball loses energy, the ball collides with the ground in successively smaller intervals of time.

Limitations

When you use model configuration parameters that optimize the simulation, such as Signal storage reuse or Block reduction, the software eliminates storage for some signals during simulation. You cannot apply a Floating Scope to these eliminated signals. To work around this issue, configure an eliminated signal as a test point. You can then apply a Floating Scope to the signal regardless of optimization settings. To configure test points, see Configure Signals as Test Points.

  • If you step back the simulation after adding or removing a signal, the Floating Scope clears the existing data. New data does not appear until the simulation steps forward again.

  • When connected to a constant signal, the scope plots a single point.

  • Simulink messages are not supported for Floating Scope block and Scope Viewer.

  • You cannot connect signals from for-each subsystems.

  • Scope displays have limitations in Rapid Accelerator mode. See Behavior of Scopes and Viewers in Rapid Accelerator Simulations

Ports

Input

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Connect the signals that you want to visualize. The block can have up to 96 input ports. Input signals can have these characteristics:

  • Type — Continuous (sample-based) or discrete (sample-based and frame-based).

  • Data type — Any data type that the software supports. See Data Types Supported by Simulink.

    This block accepts fixed-point input signals but converts the signal to double for display.

  • Dimension — Scalar, one dimensional (vector), two dimensional (matrix), or multidimensional (array). Display multiple channels within one signal depending on the dimension. See Signal Dimensions and Determine Signal Dimensions.

Input Limitations

  • When the input is a constant signal, the scope plots a single point.

  • When the input is an event signal, and you set the Plot type to Auto, the scope shows the event signal using a stem graph. To change the plot type and show the signal as a continuous signal, set Plot type to Line.

  • The scope shows gaps in the display when the signal contains NaN values.

  • When you visualize multiple signals in the scope, the scope may not display some samples of signals with a frame size of 1. To visualize these signals, move the signals with frame size of 1 to a separate scope.

Bus Support

You can connect nonvirtual bus and arrays of bus signals to a scope. To display the bus signals, use the normal or accelerator simulation mode. The scope displays each bus element signal in the order the elements appear in the bus, from the top to the bottom. The scope flattens nested bus elements.

To log nonvirtual bus signals with a scope, set the Save format parameter to Dataset. You can use any Save format to log virtual bus signals.

Data Types: single | double | half | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64 | Boolean | fixed point | enumerated | bus
Complex Number Support: Yes

Parameters

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Scope Tab

Scope tab of the Floating Scope and Scope Viewer.

Settings > General

Select this parameter to open the scope window when simulation starts.

Programmatic Use

See OpenAtSimulationStart.

Specify the dimensions of the display grid as a two-element numeric vector, with each element greater than 0 and less than or equal to 16.

Programmatic Use

See LayoutDimensions.

Method of processing the input signals, specified as one of these options:

  • Elements as channels (sample based) — Process each element of the input as an independent channel.

  • Columns as channels (frame based) — Process each column of the input as an independent channel. Frame-based processing is available only with discrete input signals.

Dependencies

Frame-based processing requires a DSP System Toolbox license. For more information, see Sample- and Frame-Based Concepts (DSP System Toolbox).

Programmatic Use

See FrameBasedProcessing.

  • Auto –– If Title and Y-axis label parameters are not specified, maximize all plots.

  • On –– Maximize all plots. Values in Title and Y-axis label are hidden.

  • Off –– Do not maximize plots.

Programmatic Use

See MaximizeAxes.

Settings > Time

Specify the length of the x-axis to display as one of these options:

  • Auto — Difference between the simulation start and stop times.

    The block calculates the beginning and end times of the time range using the Time display offset and Time span parameters. For example, if you set Time display offset to 10 and Time span to 20, the scope sets the time range from 10 to 30.

  • One frame period — Use the frame period of the input signal. This option is available only when you set the Input processing parameter to Columns as channels (frame based).

  • <user-defined> — Enter any value less than the total simulation time.

Programmatic Use

See TimeSpan.

Specify how to display data beyond the visible x-axis range.

You can see the effects of this option only when plotting is slow with large models or small step sizes.

  • Wrap — Draw a full screen of data from left to right, clear the screen, and then restart drawing the data from the left.

  • Scroll — Move data to the left as new data is drawn on the right. This mode is graphically intensive and can affect run-time performance.

Programmatic Use

See TimeSpanOverrunAction.

Specify the x-axis units as one of these options:

  • Metric (based on Time Span) — Display time units based on the length of Time span.

  • Seconds — Display time in seconds.

  • None — Do not display time units.

Programmatic Use

See TimeUnits.

Offset the x-axis by a specified time value, specified as a real number or vector of real numbers.

For input signals with multiple channels, you can enter a scalar or vector:

  • Scalar — Offset all channels of an input signal by the same time value.

  • Vector — Independently offset the channels.

Programmatic Use

See TimeDisplayOffset.

Specify how the x-axis (time) and tick labels display:

  • All — Display x-axis labels on all y-axes.

  • None — Do not display labels. Selecting None also clears the Show time-axis label parameter.

  • Bottom displays only — Display x-axis label on the bottom y-axis.

Programmatic Use

See TimeAxisLabels.

Select this parameter to show the time offset on the status bar.

Select this parameter to show the x-axis label for the active display.

Dependencies

To enable this parameter, set T-axis and ticks labels to All or Bottom displays only.

Programmatic Use

See ShowTimeAxisLabel.

Settings > Axes Scaling

Specify the y-axis scaling mode as one of these options:

  • Manual — Manually scale the y-axis range.

  • Auto — Scale the y-axis range during and after simulation. Selecting this option enables the Y-axis limits do not shrink parameter. If you want the y-axis range to increase and decrease with the maximum value of a signal, set Scale Y-axis limits to Auto and clear the Y-axis limits do not shrink parameter.

  • After N Updates — Scale y-axis after the number of time steps specified in the Number of updates parameter (10 by default). Scaling occurs only once during each run.

Programmatic Use

See AxesScaling.

Select this parameter to allow y-axis range limits to increase during simulation.

Dependencies

To enable this parameter, set Scale Y-axis limits to Auto.

Set this parameter to delay auto scaling the y-axis.

Dependencies

To enable this parameter, set Scale Y-axis limits to After N Updates.

Programmatic Use

See AxesScalingNumUpdates.

When you select this parameter, the scope scales the y-axis limits only when the simulation stops. When you clear this parameter, the scope scales the y-axis limits continuously.

Specify the percentage of the y-axis range used for plotting data. If you set this parameter to 100, the plotted data uses the entire y-axis range.

Specify where to align plotted data along the y-axis data range when Y-axis data range (%) is set to less than 100 percent.

  • Top — Align signals with the maximum values of the y-axis range.

  • Center — Center signals between the minimum and maximum values.

  • Bottom — Align signals with the minimum values of the y-axis range.

Select this parameter to scale the time-axis (x-axis) range to fit all signal values. If Scale Y-axis limits is set to Auto, the data currently within the axes is scaled rather than the entire signal in the data buffer.

Specify the percentage of the time-axis (x-axis) range to plot data on. For example, if you set this parameter to 100, plotted data uses the entire x-axis range.

Dependencies

To enable this parameter, select Scale T-axis limits.

Specify where to align plotted data along the time-axis (x-axis) data range when T-axis data range (%) is set to less than 100 percent.

  • Right — Align signals with the maximum values of the x-axis range.

  • Center — Center signals between the minimum and maximum values.

  • Left — Align signals with the minimum values of the x-axis range.

Dependencies

To enable this parameter, select Scale T-axis limits.

Settings > Logging

Select this parameter to limit data saved by the scope internally. When you select this parameter, the scope saves the last n data points to a MATLAB® variable specified in Variable name.

n is the scalar value you specify in the Max points parameter.

When you select this parameter, the scope can plot signals for less than the entire time range of a simulation, for example, if the sample time is small. If the scope plots only a portion of the signal, consider increasing the number of data points to save.

When you clear this parameter, the scope saves all the data. You can visualize the entire data in the scope after the simulation finishes. For simulations with Stop Time set to inf, consider selecting this parameter.

Note

If you do not select this parameter and you have a high sample rate or long simulation time, you can experience issues with memory or system performance.

Programmatic Use

See DataLoggingLimitDataPoints.

Specify the maximum number of data points n to save as a positive integer. The scope saves the last n data points to the MATLAB variable specified in Variable name.

Dependencies

To enable this parameter, select Limit data points to last.

Programmatic Use

See DataLoggingMaxPoints.

Select this parameter to plot and log (save) scope data every Nth data point, where N is the decimation factor you specify in the Decimation value parameter.

When you select this parameter and specify a scalar value in the Decimation value parameter, the scope limits the data points plotted and saved to the MATLAB variable specified in Variable name.

When you clear this parameter, the scope saves all the scope data.

Programmatic Use

See DataLoggingDecimateData and DataLoggingDecimation.

Specify the scope to save or log data every Nth data point, where N is the value you specify in this parameter.

A value of 1 buffers all the data values.

Dependencies

To enable this parameter, select Decimation.

Programmatic Use

See DataLoggingDecimateData and DataLoggingDecimation.

Enable or disable logging for viewed signals, excluding signals in model reference, Stateflow®, and libraries. For more logging options, right-click on the signal line, and then click the Properties button .

Settings > Axes Style

Specify the type of plot:

  • Auto –– The plot type is a line graph for continuous signals, a stair-step graph for discrete signals, and a stem graph for Simulink message signals.

  • Line –– Line graph.

  • Stairs –– Stair-step graph. A stair-step graph consists of only horizontal and vertical lines. Each horizontal line represents the signal value for a discrete sample period and is connected to two vertical lines. Each vertical line represents the change in the signal value that occurs at a specific sample time.

  • Stem –– Stem graph displayed as circles at the input value with vertical lines to the x-axis.

Select the background color for the scope display.

Select the axes, grid, and label color for individual displays.

Select the background color for the scope window.

Select this parameter to preserve colors when copying the scope display to the clipboard. When you do not select this parameter, the scope changes the color of the scope to be printer friendly (white background, visible lines). To preserve the existing colors on the scope while copying, select this parameter.

Display Properties

Select the display that updates based on the settings in the Display Properties > Line Style, Y-axis, and Display.

Specify the display using a positive integer that corresponds to the column-wise placement index. For layouts with multiple columns and rows, display numbers are mapped down and then across.

Dependencies

To enable this parameter, set the display grid to have more than one display. Under Settings > General, set Display grid to a two-element numeric vector with at least one of the values greater than 1.

Programmatic Use

See ActiveDisplay.

Note

All the Line Style parameters affect only the active display that you select through the Active Display parameter.

Settings > Line Style

Select the active line for setting line style parameters.

Select the line style for the active line that you select using the Line parameter.

Specify the line width for the active line that you select using the Line parameter.

Specify a data point marker for the active line that you select using the Line parameter. This parameter is similar to the 'Marker' parameter for plots. You can choose any of the marker symbols from the drop-down list.

Specify the line color for the active line that you select using the Line parameter.

Tunable: Yes

Show or hide a signal on the plot.

Select this parameter to display signal on the plot. If you clear this parameter, the signal you select is no longer visible.

Note

All the Y-axis properties affect only the active display that you select through the Active Display parameter.

Settings > Y-axis

Specify the text to display on the y-axis. To display signal units, add (%<SignalUnits>) to the label. At the beginning of a simulation, the software replaces (%SignalUnits) with the units associated with the signals.

Example: For a velocity signal with units of m/s, enter Velocity (%<SignalUnits>).

Dependencies

If you select the Plot as magnitude-phase parameter under Display settings, this parameter does not apply. The y-axes are labeled Magnitude and Phase.

Programmatic Use

See YLabel.

Specify the y-axis limits as a two-element numeric vector.

Tunable: Yes

Dependencies

If you select Plot as magnitude-phase, this parameter only applies to the magnitude plot. The y-axis limits of the phase plot are always [-180 180].

Programmatic Use

See YLimits.

Note

All the Display parameters affect only the active display that you select through the Active Display parameter.

Settings > Display

Specify the title for the display. The default value %<SignalLabel> uses the input signal name for the title.

Programmatic Use

See Title.

Select this parameter to display the signal legend. The names listed in the legend are the signal names from the model. For signals with multiple channels, the scope appends a channel index after the signal name. Continuous signals have straight lines before their names, and discrete signals have step-shaped lines.

From the legend, you can control which signals are visible. This control is equivalent to changing the visibility in the Line Style parameters. In the scope legend, click a signal name to hide the signal in the scope. To show the signal, click the signal name again. To show only one signal, right-click the signal name, which hides all other signals. To show all signals, press Esc.

Note

The legend only shows the first 20 signals. Any additional signals cannot be controlled from the legend.

Programmatic Use

See ShowLegend.

Select this parameter to show internal grid lines.

Programmatic Use

See ShowGrid.

Select this parameter to split the display into magnitude and phase plots.

  • On — Display magnitude and phase plots. If the signal is real, the scope plots the absolute value of the signal for the magnitude. The phase is 0 degrees for positive values and 180 degrees for negative values. This feature is useful for complex-valued input signals. If the input is a real-valued signal, selecting this parameter returns the absolute value of the signal for the magnitude.

  • Off — Display signal plot. If the signal is complex, the scope plots the real and imaginary parts on the same y-axis.

Programmatic Use

See PlotAsMagnitudePhase.

Display Grid

Specify the layout of the displays. Clicking Display Grid opens a grid picker similar to the scope layout. The layout can have a maximum of 16 rows and 16 columns.

Animated GIF of changing the layout from one display to two displays

If the number of displays is equal to the number of ports, signals from each port appear on separate displays. If the number of displays is less than the number of ports, signals from additional ports appear on the last display. For layouts with multiple columns and rows, ports are mapped down then across. If the number of displays is greater than the number of ports, the scope creates empty tiles.

Programmatic Use

See LayoutDimensions.

Dock

Click Dock or Dock Scope in the Scope tab to add the currently active scope to the scope container. Click Dock All Scopes to add all the opened scopes in the current model to the scope container.

For more information on the scope container, see Scope Window Management.

Click Undock in the Home tab of the scope container to remove the currently active scope from the container into a separate stand-alone window. Click Undock All to remove all scopes from the container into separate stand-alone windows.

For more information on the scope container, see Scope Window Management.

Dependencies

This parameter is available only on the Home tab of the scope container.

Select this parameter to add the newly opened scopes (that have not been opened before in the current MATLAB session) automatically to the existing scope container.

For more information on the scope container, see Scope Window Management.

Dependencies

This parameter is available only on the Home tab of the scope container. To access this parameter, click the drop down arrow of Dock All under the Home tab of the scope container.

Measurements Tab

The Measurements tab contains the settings for all the signal measurements that the scope supports. The measurement panels appear at the bottom of the scope UI. To open a measurement panel, you must first enable the corresponding measurement in the Measurements tab.

Measurements tab of the Floating Scope and Scope Viewer.

For more information on the measurements, see these pages:

  • Triggers — Set triggers to sync repeating signals and pause the display when events occur.

  • Cursor Measurements — Measure signal values using vertical and horizontal cursors.

  • Signal Statistics — Display the maximum, minimum, peak-to-peak difference, mean, median, and RMS values of a selected signal.

  • Peak Finder — Find maxima, showing the x-axis values at which they occur.

  • Bilevel Measurements — Measure transitions, overshoots, undershoots, and cycles.

Block Characteristics

Data Types

Boolean | double | enumerated | fixed point | integer | single

Direct Feedthrough

no

Multidimensional Signals

yes

Variable-Size Signals

yes

Zero-Crossing Detection

no

More About

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Extended Capabilities

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Version History

Introduced in R2015b

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See Also

Blocks

Topics