Data Logging

Log data to workspace during model simulation for subsequent data processing

You can log simulation data to the workspace, or to a temporary file on disk, for debugging and verification. Data logging lets you analyze how internal block variables change with time during simulation. If you log simulation data, you can later query, plot, and analyze it without rerunning the simulation. You can use Simscape™ data logging and selective logging instrumentation to log block variable data.

Simscape data logging logs all variables for selected blocks or for all blocks in the model and outputs the data to the simulation log workspace variable. You can interactively visualize and navigate the Simscape data logging results with the Simscape Results Explorer tool. You can use data logging and the Simscape Results Explorer to view simulation results, instead of adding sensors and scopes to your model. To learn more, see Log, Navigate, and Plot Simulation Data.

Selective logging logs only the selected variables on the blocks with logging enabled. Simscape logs the variables to a Simulink.SimulationData.Dataset object, along with Simulink^® signals. You can enable selective logging for Simscape blocks with the user interface. You can view and select block variables for logging in the Instrumentation Table without compiling the model. To visualize the selective logging results, use the Simulation Data Inspector. To learn more, see Log Selected Block Variables.

You also manage selective logging instrumentation programmatically. To learn more, see Log Selected Variables Programmatically.

Tools

Simscape Results Explorer

Navigate and plot simulation data logging results

Functions

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Simscape Data Logging Objects

`simscape.logging.Node`	Hierarchy tree for simulation data
`simscape.logging.Series`	Time-value series for simulation data

Simscape Data Logging Functions

`simscape.logging.export`	Save logged simulation data in MLDATX file
`simscape.logging.import`	Create simulation log variable to access data in MLDATX file
`simscape.logging.plot`	Plot logged simulation data for Node or Series
`simscape.logging.plotxy`	Plot logged simulation data for one node or series against another
`simscape.logging.findNode`	Find `Node` object corresponding to block or subsystem (Since R2020a)
`simscape.logging.sli.findNode`	(To be removed) Find `Node` object corresponding to block or subsystem
`simscape.logging.findPath`	Find path to node in logged simulation data tree (Since R2020a)
`simscape.logging.sli.findPath`	(To be removed) Find path to node in logged simulation data tree
`simscape.logging.getSimulationLog`	Identify latest Simscape simulation log for a model (Since R2024a)
`simscape.logging.timestamp`	Determine whether simulation log is current or stale (Since R2021a)
`sscexplore`	Open Simscape Results Explorer to interact with logged simulation data
`sscprintzcs`	Print zero crossing information for logged simulation data

Selective Logging Objects

`simscape.instrumentation.Variable`	Container for Simscape variable logging information (Since R2024a)
`simscape.instrumentation.VariableTable`	Store and manage block variable data (Since R2024a)
`simscape.instrumentation.VariableConfiguration`	Configuration for variable (Since R2024a)

Selective Logging Functions

`simscape.instrumentation.defaultVariableTable`	Return default VariableTable object for block (Since R2024a)
`simscape.instrumentation.setVariableTable`	Set the VariableTable object for a block (Since R2024a)
`simscape.instrumentation.getVariableTable`	Get current VariableTable object for block (Since R2024a)
`simscape.instrumentation.isLoggingEnabled`	Return whether block variables have logging enabled (Since R2024a)

Model Settings

Log simulation data	Option to specify whether to log Simscape simulation data to workspace
Log simulation statistics	Option to specify whether to log simulation statistics as part of simulation data
Record data in Simulation Data Inspector	Option to specify whether to stream Simscape data to Simulation Data Inspector
Open viewer after simulation	Option to specify whether to open Simscape Results Explorer at the end of simulation run
Workspace variable name	Name of workspace variable for Simscape simulation data logging
Decimation	Option to reduce logged data points by skipping time steps
Limit data points	Option to limit number of logged data points
Data history (last N steps)	Number of data points to log

Topics

Simscape Data Logging

About Simscape Data Logging
You can log Simscape simulation data to the workspace, or to a temporary file on disk, for debugging and verification.
Enable Simscape Data Logging for the Whole Model
Using data logging for the whole model is a best practice.
Log Data for Selected Blocks Only
Instead of logging Simscape simulation data for the whole model, you can log data just for the selected blocks.
Data Logging Options
Additional options for logging and displaying the simulation data.
Stream Logging Data to Disk
When you log simulation data, you can stream the data to a temporary file on disk and have the workspace variable point to that temporary file.
Saving and Retrieving Logged Simulation Data
Methods of storing logged simulation data for future use and retrieving it at a later time.
Log, Navigate, and Plot Simulation Data
This example shows the basic workflow for logging simulation data for the whole model and then navigating and plotting the logged data using Simscape Results Explorer.
Log and Plot Simulation Data
This example shows how you can log and plot simulation data instead of adding sensors to your model.
Log Simulation Statistics
This example shows how you can access and analyze information on zero crossings during simulation.
Log and View Simulation Data for Selected Blocks
This example shows how you can set your model to log simulation data for selected blocks only and how to view simulation data using Simscape Results Explorer.
Plot Simulation Data in Different Units
When you display logged simulation data in Simscape Results Explorer, you can change the y-axis units directly on the plot.
Use Custom Units to Plot Simulation Data
This example shows how you can change to a custom unit display of logged simulation data.
Indexing into Component Arrays
You can use command-line interface to index into an array of components, for example, to get or set operating point targets for a particular array member, or to plot simulation data.

Selective Logging

About Selective Logging
You can output data for selected Simscape block variables along with Simulink variables and signals.
Log Selected Block Variables
Log data for an individual block variable.
Log Selected Variables Programmatically
Programmatically configure selective logging.