Signal logging

R2026b

Option to log data for signals marked for logging in model

Model Configuration Pane: Data Import/Export

Description

The Signal logging parameter specifies whether the simulation logs data for signals marked for logging in the model. When you enable signal logging, the data logs to the workspace and the Simulation Data Inspector.

By default, the data logs to a property of the Simulink.SimulationOutput object with the name logsout. To access the logged signal data, use dot notation. For example, when you use the default output variable name out and the default signal-logging variable name logsout, access the signal data using this command.

logsout = out.logsout;

Settings

on (default) | off

on

The simulation logs data for signals marked for logging in the model to the workspace and the Simulation Data Inspector.

By default, the property of the Simulink.SimulationOutput object that contains the logged signal data has the name logsout. To log data to a property with a different name, enter the name in the box. The name must be a valid MATLAB^® variable name and must not match the name of any object functions or properties of the Simulink.SimulationOutput object. For more information, see Variable Names.

Signal logging always saves data using the Dataset format.

Data for variable-size signals is saved as a timetable that contains a cell array of values for each time step.

off

The simulation does not log signal data during simulation, even if signals are marked for logging in the model.

Tips

• If you select Signal logging, you can use the Configure Signals to Log button to open the Signal Logging Selector. You can use the Signal Logging Selector to:

  • Review all signals in a model hierarchy that are configured for logging.

  • Override signal logging settings for specific signals.

  • Control signal logging throughout a model reference hierarchy.

  You can use the Signal Logging Selector for both Simulink^® and Stateflow^® signals.

  For details about the Signal Logging Selector, see View Logging Configuration Using the Signal Logging Selector and Override Signal Logging Settings.

• For information about logging Simscape™ data, see About Simscape Data Logging (Simscape).

Programmatic Use

Parameter: SignalLogging

Type: string | character vector

Value: "on" | "off"

Default: 'on'

Parameter: SignalLoggingName

Type: string | character vector

Value: valid MATLAB variable name

Default: 'logsout'

Limitations

• Signal logging is not supported for:

  • Signals inside Stateflow charts for rapid accelerator simulations

  • Input signals of function-call subsystems, if-action subsystems, or switch case action subsystems

  • Input signals for Merge blocks

  • Outputs of Function-Call Generator blocks

  • Outputs of Trigger and Enable blocks

  • Buses inside for-each subsystems

  • Signals in referenced models inside for-each subsystems when:

    • The model that contains the for-each subsystem simulates in rapid accelerator mode.

    • The for-each subsystem is inside a referenced model simulated in accelerator mode.

    For more information about logging signals in for-each subsystems, see Log Signals in For-Each Subsystems.

  • State port outputs of Integrator and Discrete-Time Integrator blocks.

Version History

Introduced before R2006a

R2026b: Log Simulink DateTime signals

Signal logging supports logging DateTime signals to the workspace as datetime data. For more information, see Simulink DateTime.

R2023b: Log unbounded variable-size signals

In normal and accelerator mode simulations, you can log an unbounded variable-size signal using signal logging. Logging is not supported for nonvirtual buses that contain unbounded variable-size signals.

R2023a: Log nonvirtual buses that contain variable-size signals

In normal and accelerator mode simulations, you can log:

• Nonvirtual buses that contain variable-size signals directly or in nested buses

• Buses with nested nonvirtual buses that contain variable-size signals

In normal mode simulations only, you can log:

• Arrays of buses with nonvirtual buses that contain variable-size signals

R2021a: Variable-size signal support

You can mark variable-size signals for logging when you use the Dataset format.

Data for variable-size signals is saved as a timetable that contains a cell array of values for each time step.

R2019a: Signal logging parameter controls whether data streams to Simulation Data Inspector

Since R2017a, signals you mark for logging also stream to the Simulation Data Inspector. Between R2017a and R2019a, the data always streamed to the Simulation Data Inspector, even when you disabled the Signal logging parameter. Starting in R2019a, data for signals you mark for logging streams to the Simulation Data Inspector only when you enable the Signal logging parameter.

R2017a: Unified streaming and logging

When you mark a signal for logging, the data for that signal streams to the Simulation Data Inspector during simulation in addition to being logged to the workspace. In previous releases, you marked signals for logging and streaming separately. Streaming badges are converted to logging badges.

Data for signals that are marked for logging always streams to the Simulation Data Inspector, even when you disable the Signal logging parameter for the model. When you disable the Signal logging parameter, the data does not log to the workspace.