Signals

Configure and display signal properties

Signals transmit data between two blocks in a simulation. The data could be the calculated output of a block, or simply a message. The value of signals are calculated at all points during the simulation time. You can display the signal data and properties during and after simulation, see the real-time values on a block diagram, or you can log the values as variables in the workspace. Also, you can export the signals to a file or to a workspace to investigate further.

You can control the mathematical behavior of a model by specifying signal characteristics such as numeric data type, initial value, and value range. For more information, see Signal Basics.

Blocks

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Signal Properties

Signal Specification	Specify desired dimensions, sample time, data type, numeric type, and other attributes of signal
IC	Set initial value of signal
Probe	Output signal attributes, including width, dimensionality, sample time, and complex signal flag
Rate Transition	Handle transfer of data between blocks operating at different rates
Signal Editor	Display, create, edit, and switch interchangeable scenarios
Weighted Sample Time	Support calculations involving sample time
Width	Output width of input vector

Signal Conversion

Bus to Vector	Convert virtual bus to vector
Signal Conversion	Convert signal to new type without altering signal values

Functions

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Signal Properties

`disableimplicitsignalresolution`	Convert model to use only explicit signal resolution
`signalBuilderToSignalEditor`	Import signal data and properties from Signal Builder block to Signal Editor block
`Simulink.Signal`	Specify instance-specific properties of signal or discrete state
`Simulink.ValueType`	Specify common set of signal properties for reuse (Since R2021b)

Signal Tracing

`sltrace`	Analyze structure of model by tracing signal sources and destinations (Since R2021b)
`highlight`	Highlight path to signal sources or destinations in model (Since R2021b)
`removehighlight`	Remove highlighting for `sltrace.Graph` object from model (Since R2021b)

Objects

sltrace.Graph Signal path traced using sltrace function (Since R2021b)

Tools

Signal Properties	View and edit signal properties
Instrumentation Properties	View and edit logging and visualization properties for logged signal
Property Inspector	Edit parameters and properties for any Simulink model element
Model Data Editor	Inspect and edit data items (signals, parameters, and states) in a table that you can sort, group, and filter
Component Interface View	Display component interfaces to trace port connections and author ports

Model Settings

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Connectivity Diagnostics

Signal label mismatch	Diagnostic action to take when signal has multiple names through propagation
Unconnected block input ports	Diagnostic action to take when block has unconnected input
Unconnected block output ports	Diagnostic action to take when block has unconnected output
Unconnected line	Diagnostic action to take when model has unconnected line or unmatched Goto or From block

Topics

Get Started with Signals

Signal Basics
Create, configure, identify, and test signals.
Signal Types
Learn about different types of signals, such as control signals and composite signals.
Signal Groups
Test or debug models by creating interchangeable groups of signal data.

Signal Properties

Investigate Signal Values
Initialize, access, and view the values that signals have during a simulation run.
Specify Signal Ranges
Specify the minimum and maximum value that a signal can attain during simulation. Fully specify your design and optimize data types and the generated code by specifying the minimum and maximum value that a signal can attain during simulation.
Determine Signal Dimensions
Inspect and control signal dimensionality.
How Simulink Propagates Signal Properties in a Model
Inspect how Simulink^® propagates signal properties in a model.
Initialize Signals and Discrete States
Some systems contain signals and states whose initial values you must specify, for example, the starting position and velocity of a bouncing ball.
Configure Signals as Test Points
Use test points to exclude signal lines from optimizations which enables you to access the simulation data.
Specify Common Set of Signal Properties as Value Type
Create a reusable value type for common signal properties, such as the application-specific signal properties of wind velocity. (Since R2021b)

Display Signal Properties

Highlight Signal Sources and Destinations
Trace a signal to its source or destination while debugging or exploring a model.
View Signal Values Using Port Value Labels
View signal values in the block diagram during simulation to understand, analyze, and debug your model.
Display Signal Attributes
Improve model readability by displaying signal attributes, such as data types and dimensions, in the block diagram.
Signal Label Propagation
Name a signal to identify and access it more easily. Take advantage of signal label propagation to reduce the effort of naming a signal that crosses system boundaries.
Trace Connections and Author Ports Using Component Interface View
Display component interfaces to trace port connections and author ports.

Variable-Size Signals

Variable-Size Signal Basics
Create a variable-size signal whose size and values can change during a simulation.
Inspect Variable-Size Signals on Simulink Models
Inspect example models that show how to use variable-size signals.
Unbounded Variable-Size Signals
Model unknown size data using dynamic arrays.

Related Information

Featured Examples

Value Types at Component Interfaces

Assign a meaningful name to a set of properties at an interface and reuse that set of properties with value types.

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Find Shortest Control Path in Simulink Model

How to find the shortest control path for a hybrid electrical vehicle using Signal Tracing Command-line API.

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Arithmetic Operations on Matrix Signals

Perform arithmetic operations on signals carrying matrix and vector data.

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Model Feedback Control System

Model a feedback control system using Simulink® signals that carry matrix and vector representations of different components of the feedback system. In this example, the controller is designed for a buck-boost converter to track a reference voltage signal. Buck-boost converters are extensively used in distributed power supply systems and modern power electronics devices due to their high efficiency, high power density, low cost, and compact size.

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Bounded Variable-Size Signal Basic Operations

Generate bounded variable-size signals and illustrates some of the operations using those signals. In this example, you generate variable-size signals using the Selector block and the Switch block. The signals are used in math operations, bus creation, bus selection, matrix concatenation and to implement a discrete filter equation.

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Variable-Size Signal Length Adaptation

Model showing how to change the length of a signal over time.

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Multimode Variable-Size Signal

Use different operation modes to correspond to different signal sizes.

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Merging Signals

Use conditionally executed subsystems and the Merge block to combine two inputs into a single output.

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Unbounded Variable-Size Signal Basic Operations

Use unbounded variable-size signals in Simulink® modeling. For more information about the general concept of unbounded variable-size signals, see Unbounded Variable-Size Signal.

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Use Unbounded Variable-Size Signals Between Model Components

Use unbounded variable-size signals to handle unbounded-size data between different model components. The example also shows how to prepare the model for C++ code generation.

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