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Signal Properties

View and edit signal properties

Description

Use the Signal Properties dialog box to view and edit properties for signals in your model. Using the Signal Properties dialog box, you can mark a signal for logging, specify a signal name, and configure logging options, including which data points to log and the logging sample time.

When your model is configured for concurrent execution, the Signal Properties dialog box also includes a Data Transfer tab. For more information, see Configure Data Transfer Settings Between Concurrent Tasks and Configure Your Model for Concurrent Execution.

Signal Properties dialog box

Open the Signal Properties

  • Right-click a signal line in the model and select Properties.

  • When you select a signal line in your model, the Signal Properties are available in the Property Inspector.

Parameters

Signal Name Properties

Specify a name for the signal as a character vector or string.

When you select Signal name must resolve to Simulink signal object, the name must match the name of a Simulink.Signal object in the base workspace, the model workspace, or a data dictionary. The signal name can implicitly resolve to a Simulink.Signal object when you do not select Signal name must resolve to Simulink signal object. For more information, see Explicit and Implicit Symbol Resolution.

Programmatic Use

To specify a signal name programmatically, use the set_param function to set the Name property for the line handle that corresponds to the signal. For an example, see Name a Signal Programmatically.

When enabled, the signal name specified in the Signal Properties dialog box must match the name of a Simulink.Signal object in the base workspace, the model workspace, or a data dictionary. When disabled, the signal name can implicitly resolve to a Simulink.Signal object. For more information, see Explicit and Implicit Symbol Resolution.

By default, signals that require resolution to a Simulink.Signal object are marked with the signal resolution icon to the left of the signal label. For more information, see Signal to Object Resolution Indicator.

Programmatic Use

To configure this option for a signal programmatically, use the set_param function to set the MustResolveToSignalObject property for the line handle that corresponds to the signal. For an example, see Use Signal Objects.

When a downstream signal originates from a block that supports signal label propagation, you can enable this option on the downstream signal line to display the propagated signal name as a label on the signal line.

For example, the output signal from the Subsystem block is configured for signal label propagation. The propagated signal label <const> comes from the name of the upstream Constant block output signal const.

For more information see, Signal Label Propagation.

Tips

To display propagated signal labels for all signals, in the Simulink® Editor, on the Debug tab, select Information Overlays, then select Propagated Signal Labels.

Programmatic Use

To configure a signal to display its propagated name programmatically, use the set function to specify the value of the SignalPropagation property for the line handle that corresponds to the signal. For an example, see Display Propagated Signal Labels.

Logging and Accessibility

Select this option to mark a signal for logging. When the Signal logging option in the model configuration parameters is enabled, data for signals marked for logging is sent to the workspace and the Simulation Data Inspector during simulation. For more information, see Export Signal Data Using Signal Logging.

Programmatic Use

You can control whether to log a signal programmatically using the Simulink.sdi.markSignalForStreaming function or by using the set_param function to configure the DataLogging property of the port handle that corresponds to the block output port that produces the signal.

When enabled, the signal is designated as a test point. For more information, see Configure Signals as Test Points.

Programmatic Use

To designate a signal as a test point programmatically, use the set_param function to specify the value of the TestPoint property for the port handle that corresponds to the block output port that produces the signal.

Specify a name for the logged signal data. By default, logged signal data uses the name of the signal specified in the model.

To specify a logging name for a signal that is different from the name of the signal in the model, select Custom and specify the logging name in the text box.

Programmatic Use

To specify the logging name programmatically, use the set_param function to configure the DataLoggingNameMode and DataLoggingName parameters for the port handle that corresponds to the block output port that produces the signal. For an example, see Signal-Specific Logging Name Specified Programmatically.

When you only want to save or analyze the data from the end of a simulation, you can configure logging to capture only the last n signal values. Select Limit data points to last and specify the number of data points you want to log.

When you only log the last simulation values, dashboard blocks and the Simulation Data Inspector do not display data during simulation. Consider data requirements for each signal before you reduce the number of data points logged in simulation.

For more information, see Specify Signal Values to Log and Limit the Size of Logged Data.

Programmatic Use

To configure this option programmatically, use the set_param function to specify the DataLoggingLimitDataPoints and DataLoggingMaxPoints parameters for the port handle that corresponds to the block output port that produces the signal.

When you want to reduce the effective sample rate for logged data, select Decimation and specify the desired decimation factor in the text box. For example, if you specify a decimation factor of 2, every other signal value is logged.

Consider data requirements for each signal before reducing the number of data points logged in simulation. Decimation can cause aliasing if the effective sample rate is too low.

For more information, see Specify Signal Values to Log and Limit the Size of Logged Data.

Specify the sample time to use for logging the data for the selected signal. By default, the logging sample time is inherited (-1) from the block that produces the signal. For continuous logging sample time, specify the value as 0. To use a discrete sample time for logging data, specify the sampling interval as a scalar.

Specifying a logging sample time may add a new sample time to the model. When you specify a logging sample time, the model calculates a value for the exact time hits. When you use a fixed-step solver, the logging sample time you specify must be a multiple of the base rate for the model.

Logging sample time is not supported for signals inside conditional subsystems or conditional referenced models.

Documentation

You can provide a description of the signal that shows in the Info tab of the Property Inspector when the signal is selected.

The description specified in the Signal Properties dialog box does not appear in generated code. To provide a signal description that becomes a comment in generated code, use a Simulink.Signal object.

Specify a MATLAB expression that opens documentation for the signal. For example, you can call the web function to open an HTML file. When you specify a value for the Document link property, you can click the Document link field label to open the document.

Programmatic Use

To programmatically specify a document link, use the set_param property to specify the DocumentLink property of the port handle that corresponds to the block output port that produces the signal.

Introduced before R2006a