Switch

Allow different data input sizes

Select this check box to allow input signals with different sizes.

Settings

Default: Off

On

Allows input signals with different sizes, and propagates the input signal size to the output signal. If the two data inputs are variable-size signals, the maximum size of the signals can be equal or different.

Off

Inputs signals must be the same size.

Command-Line Information

Parameter: AllowDiffInputSize

Type: string

Value: 'on' | 'off'

Default: 'off'

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Switch

Output minimum

Specify the minimum value that the block should output.

Settings

Default: []

The default value is [] (unspecified).

Simulink uses this value to perform:

•Parameter range checking (see “Check Parameter Values”) for some blocks

•Simulation range checking (see “Signal Ranges”)

•Automatic scaling of fixed-point data types

Tip

This number must be a finite real double scalar value.

Command-Line Information

See “Block-Specific Parameters” on page 8-109 for the command-line information.

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Switch

Output maximum

Specify the maximum value that the block should output.

Settings

Default: []

The default value is [] (unspecified).

Simulink uses this value to perform:

•Parameter range checking (see “Check Parameter Values”) for some blocks

•Simulation range checking (see “Signal Ranges”)

•Automatic scaling of fixed-point data types

Tip

This number must be a finite real double scalar value.

Command-Line Information

See “Block-Specific Parameters” on page 8-109 for the command-line information.

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Switch

Output data type

Specify the output data type.

Settings

Default: Inherit: Inherit via internal rule

Inherit: Inherit via internal rule

Uses the following rules to determine the output data type.

Inherit: Inherit via back propagation

Uses data type of the driving block.

double

Specifies output data type is double.

single

Specifies output data type is single.

int8

Specifies output data type is int8.

uint8

Specifies output data type is uint8.

int16

Specifies output data type is int16.

uint16

Specifies output data type is uint16.

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Switch

int32

Specifies output data type is int32.

uint32

Specifies output data type is uint32.

fixdt(1,16,0)

Specifies output data type is fixed point fixdt(1,16,0).

fixdt(1,16,2^0,0)

Specifies output data type is fixed point fixdt(1,16,2^0,0).

Enum: <class name>

Uses an enumerated data type, for example, Enum: BasicColors.

<data type expression>

Uses a data type object, for example, Simulink.NumericType.

Tip

When the output is of enumerated type, both data inputs should use the same enumerated type as the output.

Command-Line Information

See “Block-Specific Parameters” on page 8-109 for the command-line information.

See Also

See “Specify Block Output Data Types” for more information.

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Switch

Mode

Select the category of data to specify.

Settings

Default: Inherit

Inherit

Specifies inheritance rules for data types. Selecting Inherit enables a list of possible values:

•Inherit via internal rule (default)

•Inherit via back propagation

Built in

Specifies built-in data types. Selecting Built in enables a list of possible values:

•double (default)

•single

•int8

•uint8

•int16

•uint16

•int32

•uint32

Fixed point

Specifies fixed-point data types.

Enumerated

Specifies enumerated data types. Selecting Enumerated enables you to enter a class name.

Expression

Specifies expressions that evaluate to data types. Selecting Expression enables you to enter an expression.

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Switch

Dependencies

Clicking the Show data type assistant button enables this parameter.

Command-Line Information

See “Block-Specific Parameters” on page 8-109 for the command-line information.

See Also

See “Specify Data Types Using Data Type Assistant”.

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Switch

Data type override

Specify data type override mode for this signal.

Settings

Default: Inherit

Inherit

Inherits the data type override setting from its context, that is, from the block, Simulink.Signal object or Stateflow chart in Simulink that is using the signal.

Off

Ignores the data type override setting of its context and uses the fixed-point data type specified for the signal.

Tip

The ability to turn off data type override for an individual data type provides greater control over the data types in your model when you apply data type override. For example, you can use this option to ensure that data types meet the requirements of downstream blocks regardless of the data type override setting.

Dependency

This parameter appears only when the Mode is Built in or Fixed point.

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Switch

Signedness

Specify whether you want the fixed-point data as signed or unsigned.

Settings

Default: Signed

Signed

Specifies the fixed-point data as signed.

Unsigned

Specifies the fixed-point data as unsigned.

Dependencies

Selecting Mode > Fixed point enables this parameter.

Command-Line Information

See “Block-Specific Parameters” on page 8-109 for the command-line information.

See Also

See “Specifying a Fixed-Point Data Type”.

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Switch

Word length

Specify the bit size of the word that holds the quantized integer.

Settings

Default: 16

Minimum: 0

Maximum: 32

Large word sizes represent large values with greater precision than small word sizes.

Dependencies

Selecting Mode > Fixed point enables this parameter.

Command-Line Information

See “Block-Specific Parameters” on page 8-109 for the command-line information.

See Also

See “Specifying a Fixed-Point Data Type” for more information.

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Switch

Scaling

Specify the method for scaling your fixed-point data to avoid overflow conditions and minimize quantization errors.

Settings

Default: Best precision

Binary point

Specify binary point location.

Slope and bias

Enter slope and bias.

Best precision

Specify best-precision values.

Dependencies

Selecting Mode > Fixed point enables this parameter. Selecting Binary point enables:

•Fraction length

•Calculate Best-Precision Scaling

Selecting Slope and bias enables:

•Slope

•Bias

•Calculate Best-Precision Scaling

Command-Line Information

See “Block-Specific Parameters” on page 8-109 for the command-line information.

See Also

For more information, see “Specifying a Fixed-Point Data Type”.

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Switch

Fraction length

Specify fraction length for fixed-point data type.

Settings

Default: 0

Binary points can be positive or negative integers.

Dependencies

Selecting Scaling > Binary point enables this parameter.

Command-Line Information

See “Block-Specific Parameters” on page 8-109 for the command-line information.

See Also

See “Specifying a Fixed-Point Data Type” for more information.

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Switch

Slope

Specify slope for the fixed-point data type.

Settings

Default: 2^0

Specify any positive real number.

Dependencies

Selecting Scaling > Slope and bias enables this parameter.

Command-Line Information

See “Block-Specific Parameters” on page 8-109 for the command-line information.

See Also

See “Specifying a Fixed-Point Data Type” for more information.

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Switch

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Switch

Examples Use of Boolean Input for the Control Port

In the sldemo_fuelsys model, the fuel_rate_control/airflow_calc subsystem uses a Switch block:

The value of the control port on the Switch block determines whether or not feedback correction occurs. The control port value depends on the output of the Logical Operator block.

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Switch

Use of Simulation Time for the Control Port

The sldemo_zeroxing model uses a Switch block:

The value of the control port on the Switch block determines when the output changes from the first input to the third input.

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Switch

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Switch Case

A Switch Case block receives a single input. Each output port is attached to a Switch Case Action subsystem. Data outputs are action signals to Switch Case Action subsystems, which you create with Action Port blocks and subsystems.

The Switch Case block uses its input value to select a case condition that determines which subsystem to execute. The cases are evaluated top down starting with the first case. If a case value (in brackets) corresponds to the value of the input, its Switch Case Action subsystem is executed.

If a default case exists, it executes if none of the other cases executes. Providing a default case is optional, even if the other case conditions do not exhaust every possible value. The following diagram shows a completed Simulink switch control flow statement:

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Switch Case

Cases for the Switch Case block contain an implied break after their Switch Case Action subsystems are executed. Thus there is no fall-through behavior for the Simulink switch control flow statement as found in standard C switch statements. The following pseudocode represents generated code for the preceding switch control example:

switch (u1) { case [u1=1]:

body_1; break;

case [u1=2 or u1=3]: body_23;

break;

default: body_default;

}

To construct the Simulink switch control flow statement shown in the above example:

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Switch Case

1Place a Switch Case block in the current system and attach the input port labeled u1 to the source of the data you are evaluating.

2Open the Switch Case block dialog box and update parameters: a Populate the Case conditions field with the individual cases.

b To show a default case, select the Show default case check box.

3Create a Switch Case Action subsystem for each case port you added

to the Switch Case block.

These consist of subsystems with Action Port blocks inside them. When you place the Action Port block inside a subsystem, the subsystem becomes an atomic subsystem with an input port labeled

Action.

4Connect each case output port and the default output port of the Switch Case block to the Action port of an Action subsystem.

Each connected subsystem becomes a case body. This is indicated by the change in label for the Switch Case Action subsystem block and the Action Port block inside of it to the name case{}.

During simulation of a switch control flow statement, the Action signals from the Switch Case block to each Switch Case Action subsystem turn from solid to dashed.

5In each Switch Case Action subsystem, enter the Simulink logic appropriate to the case it handles. All blocks in a Switch Case Action Subsystem must run at the same rate as the driving Switch Case block. You can achieve this by setting each block’s sample time parameter to be either inherited (-1) or the same value as the Switch Case block’s sample time.

Enumerated Types in Switch Case Blocks

The Switch Case block supports enumerated data types for the input signal and the case conditions. You specify enumerated case conditions

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Switch Case

as a cell array of enumerated values in the Case conditions field, for example:

{BasicColors.Red, [BasicColors.Yellow, BasicColors.Blue]}

The Switch Case block icon shows the enumerated names that correspond to the case conditions, for example:

You can use the enumeration function to specify a case condition that includes a case for every value in an enumerated type. When you use enumerated data in a Switch Case block, follow these rules:

•If the input u1 is of an enumerated type, all case condition values must be of that same enumerated type.

•If any case condition value is of an enumerated type, the input u1 and all other case condition values must be of that same enumerated type.

•When the case condition values are of an enumerated type, each value that appears as a case condition must have a different underlying integer.

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Switch Case

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Switch Case

2-1740

Switch Case

You can use colon notation to specify a range of integer case conditions. For example, entering {[1:5]} specifies that output port case[1 2 3 4 5] is run when the input value is 1, 2, 3, 4, or 5.

Depending on block size, cases with long lists of conditions are displayed in shortened form in the Switch Case block, using a terminating ellipsis (...).

You can use the enumeration function to specify a case condition that includes a case for every value in an enumerated type.

Show default case

If you select this check box, the default output port appears as the last case on the Switch Case block, allowing you to specify a default case. This case executes when the input value does not match any of the case values specified in the Case conditions field. With Show default case selected, a default output port always appears, even if the preceding cases exhaust all possibilities for the input value.

Enable zero-crossing detection

Select to enable zero-crossing detection. For more information, see “Zero-Crossing Detection” in the Simulink documentation.

Sample time (-1 for inherited)

Specify the time interval between samples. To inherit the sample time, set this parameter to -1. See “Specify Sample Time” for more information.

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Switch Case Action Subsystem

This block is a Subsystem block that is preconfigured to serve as a starting point for creating a subsystem whose execution is triggered by a Switch Case block.

Note All blocks in a Switch Case Action Subsystem must run at the same rate as the driving Switch Case block. You can achieve this by setting each block’s sample time parameter to be either inherited (-1) or the same value as the Switch Case block’s sample time.

For more information, see the Switch Case block and “Control Flow Logic” in the “Creating a Model” chapter of the Simulink documentation.

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Tapped Delay

Data Type The Tapped Delay block accepts signals of the following data types:

Support

•Floating point

•Built-in integer

•Fixed point

•Boolean

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Tapped Delay

For more information, see “Data Types Supported by Simulink” in the Simulink documentation.

Parameters and Dialog Box

Initial condition

Specify the initial output of the simulation. The Initial condition parameter is converted from a double to the input data type offline using round-to-nearest and saturation. Simulink software does not allow you to set the initial condition of this block to inf or NaN.

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Tapped Delay

Sample time

Specify the time interval between samples. To inherit the sample time, set this parameter to -1. See “Specify Sample Time” in the online Simulink documentation for more information.

Number of delays

Specify the number of discrete-time operators.

Order output vector starting with

Specify whether to output the oldest delay version first, or the newest delay version first.

Include current input in output vector

Select to include the current input in the output vector.

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Terminator

Library Sinks

Description Use the Terminator block to cap blocks whose output ports do not connect to other blocks. If you run a simulation with blocks having unconnected output ports, Simulink issues warning messages. Using Terminator blocks to cap those blocks helps prevent warning messages.

Data Type The Terminator block accepts real or complex signals of any data type

Support that Simulink supports, including fixed-point and enumerated data types.

For more information, see “Data Types Supported by Simulink” in the Simulink documentation.

Parameters and Dialog Box

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Terminator

• sldemo_fuelsys

• aero_six_dof

2-1747

Timed-Based Linearization

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Timed-Based Linearization

Use the Trigger-Based Linearization block if you need to generate linear models conditionally.

You can use state and simulation time logging to extract the model states and inputs at operating points. For example, suppose that you want to get the states of the f14 example model at linearization times of 2 seconds and 5 seconds.

1 Open the model and drag an instance of this block from the Model-Wide Utilities library and drop the instance into the model.

2Open the block’s parameter dialog box and set the Linearization time to 2 and 5.

3Open the model’s Model Configuration Parameters dialog box.

4Select the Data Import/Export pane.

5Check States and Time on the Save to Workspace control panel

6Select OK to confirm the selections and close the dialog box.

7Simulate the model.

At the end of the simulation, the following variables appear in the MATLAB workspace: f14_Timed_Based_Linearization, tout, and xout.

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Timed-Based Linearization

2-1750

Timed-Based Linearization

Parameters and

Sample time (of linearized model)

Specify a sample time to create discrete-time linearizations of the model (see “Discrete-Time System Linearization” on page 4-21).

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Time Scope

Description The Time Scope block displays signals in the time domain. The Time Scope block accepts input signals with the following characteristics:

•Continuous or discrete sample time

•Realor complex-valued

•Fixed or variable size dimensions

•Floatingor fixed-point data type

•N-dimensional

•Simulink enumerations

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Time Scope

You can use the Time Scope block in models running in Normal or Accelerator simulation modes. You can also use the Time Scope block in models running in Rapid Accelerator or External simulation modes, with some limitations. See the “Supported Simulation Modes” on page 2-1822 section for more information.

You can use the Time Scope block inside of all subsystems and conditional subsystems. Conditional subsystems include enabled subsystems, triggered subsystems, enabled and triggered subsystems, and function-call subsystems. See “About Conditional Subsystems” in the Simulink documentation for more information.

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Time Scope

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Time Scope

value. To configure a Time Scope block to have more than three input ports, select More, and enter a number for the Number of input ports parameter.

•Open the Time Scope window by double-clicking the Time Scope block in your model. To specify how many input ports the Time Scope block should have, in the Time Scope menu, select File > Number of Input Ports from the scope menu.

An input signal may contain multiple channels, depending on its dimensions. Multiple channels of data are always shown as different-colored lines on the same display.

Multiple Time Offsets

You can offset all channels of an input signal by the same number of seconds or offset each channel independently. To offset all channels equally, select View > Properties, and specify a scalar value for the Time display offset parameter on the Main pane. To offset each channel independently, specify a vector of offset values. When you specify a Time display offset vector of length N, the scope offsets the input channels as follows:

•When N is equal to the number of input channels, the scope offsets each channel according to its corresponding value in the offset vector.

•When N is less than the number of input channels, the scope applies the values you specify in the offset vector to the first N input channels. The scope does not offset the remaining channels.

•When N is greater than the number of input channels, the scope offsets each input channel according to the corresponding value in the offset vector. The scope ignores all values in the offset vector that do not correspond to a channel of the input.

Multiple Displays

You can display multiple channels of data on different displays in the Scope window. In the Scope toolbar, select View > Layout, or select

the Layout button (). This feature allows you to tile the window into

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Time Scope

a number of separate displays, up to a grid of 4 rows and 4 columns. For example, if there are three inputs to the Scope, you can display the signals in separate displays by selecting row 3, column 1, as shown in the following figure.

After you select row 3, column 1, the Scope window has three separate displays, as shown in the following figure.

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Time Scope

2-1757

Time Scope

•Minimum time-axis limit — The Time Scope sets the minimum time-axis limit using the value of the Time display offset parameter on the Time tab of the Properties dialog box. If you specify a vector of values for the Time display offset parameter, the scope uses the smallest of those values to set the minimum time-axis limit.

•Maximum time-axis limit — The Time Scope sets the maximum time-axis limit by summing the value of Time display offset parameter with the value of the Time span parameter. If you specify a vector of values for the Time display offset parameter, the scope sets the maximum time-axis limit by summing the largest of those values with the value of the Time span parameter.

•Simulation status — Provides the current status of the model simulation. The status can be one of the following conditions:

-Initializing

-Ready

-Running

-Paused

The Simulation status is part of the Status Bar in the Time Scope window. You can choose to hide or display the entire Status Bar. From the Time Scope menu, select View > Status Bar.

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Time Scope

•Time units — The units used to describe the time-axis. The Time Scope sets the time units using the value of the Time Units parameter on the Time tab of the Properties dialog box. By default,

this parameter is set to Metric (based on Time Span) and displays in metric units such as milliseconds, microseconds, minutes, days, etc. You can change it to Seconds to always display the time-axis values in units of seconds. You can change it to None to not display any units on the time-axis. When you set this parameter to None, then Time Scope shows only the word Time on the time-axis.

To hide both the word Time and the values on the time-axis, set the Show time-axis labels parameter to None. To hide both the word Time and the values on the time-axis in all displays except the

bottom ones in each column of displays, set this parameter to Bottom Displays Only. This behavior differs from the Simulink Scope block, which always shows the values but never shows a label on the x-axis.

•Time offset — The Time offset value helps you determine the simulation times for which the scope is displaying data. The value is always in the range 0≤ Time offset≤ Simulation time.

For example, if you set the Time span to 20 seconds, and you see a Time offset of 0 (secs) on the scope window, the scope is displaying data for the first 0 to 20 seconds of simulation time. When you see the Time offset change to 20 (secs), the scope is

displaying data for simulation times is greater than 20 seconds and less than or equal to 40 seconds. The scope continues to update the Time offset value until the simulation is complete.

•Simulation time — When the model is running or simulation has been paused, the scope displays the current simulation time. If the model simulation completes or is stopped, the scope displays the time at which the simulation stopped. The Simulation time is part of the Status Bar in the Time Scope window. You can choose to hide or display the entire Status Bar. From the Time Scope menu, select

View > Status Bar .

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Time Scope

Axes Maximization

You can specify whether to display the Time Scope in maximized axes mode. In this mode, the axes are expanded to fill the entire display. To conserve space, no labels appear in each display. Instead, tick-mark values appear on top of the plotted data. The following figure highlights the important indicators in this mode of the Time Scope window.

To toggle this mode, in the Time Scope menu, select View > Properties to bring up the Properties dialog box. In the Main pane, set the Maximize axes parameter. You can select one of the following options:

•Auto — In this mode, the axes appear maximized in all displays only if the Title and Y-Axis label parameters are empty for every display. If you enter any value in any display for either of these parameters, the axes are not maximized.

•On — In this mode, the axes appear maximized in all displays. Any values entered into the Title and Y-Axis label parameters are hidden.

•Off — In this mode, none of the axes appear maximized.

The default setting is Auto.

Reduce Updates to Improve Performance

By default, the Time Scope updates the displays periodically at a rate not exceeding 20 hertz. If you would like the Time Scope to update on every simulation time step, you can disable the Reduce Updates to Improve Performance option. In the Time Scope menu, select

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Time Scope

Simulation > Reduce Updates to Improve Performance to clear the check box. However, as a recommended practice, you can leave this option enabled because doing so can significantly improve the speed of the simulation.

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Time Scope

Axes Control Buttons

2-1762

Time Scope

Measurements Buttons

2-1763

Time Scope

2-1764

Time Scope

2-1765

Time Scope

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Time Scope

box. See the “Tools — Plot Navigation Options” on page 2-1817 section for more information.

Measurements Panel Buttons

Each of the Measurements panels contains the following buttons that enable you to modify the appearance of the current panel.

Button Description

Move the current panel to the top. When you are displaying more than one panel, this action moves the current panel above all the other panels.

Collapse the current panel. When you first enable a panel, by default, it displays one or more of its panes. Click this button to hide all of its panes to conserve space. After you click this

button, it becomes the expand button .

Expand the current panel. This button appears after you click the collapse button to hide the panes in the current panel. Click this button to display the panes in the current panel and show measurements again. After you click this

button, it becomes the collapse button again.

Undock the current panel. This button lets you move the current panel into a separate window that can be relocated anywhere on your screen. After you click this button, it

becomes the dock button in the new window.

Dock the current panel. This button appears only after you click the undock button. Click this button to put the current panel back into the right side of the Scope window. After you

click this button, it becomes the undock button again.

Close the current panel. This button lets you remove the current panel from the right side of the Scope window.

Some panels have their measurements separated by category into a number of panes. Click the pane expand button to show each pane

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Time Scope

that is hidden in the current panel. Click the pane collapse button to hide each pane that is shown in the current panel.

Trace Selection Panel

When you use the Scope to view multiple signals, the Trace Selection panel appears if you have more than one signal displayed and you click on any of the other Measurements panels. Choose the signal name for which you would like to display time domain measurements. See the following figure.

You can choose to hide or display the Trace Selection panel. In the Scope menu, select Tools > Measurements > Trace Selection.

Cursor Measurements Panel

The Cursor Measurements panel displays screen cursors. You can choose to hide or display the Cursor Measurements panel. In the Scope menu, select Tools > Measurements > Cursor

Measurements. Alternatively, in the Scope toolbar, click the Cursor Measurements button.

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