Simscape Model Advisor Checks

Simscape Checks Overview

Use Simscape™ Model Advisor checks to identify Simscape blocks with ambiguous setting of parameter units, or outdated Simscape blocks in your model.

See Also

• Run Model Advisor Checks

Modeling Physical Systems Checks Overview

Use the Modeling Physical Systems Model Advisor checks to identify Simscape blocks with ambiguous setting of parameter units.

See Also

• Run Model Advisor Checks

Check consistency of block parameter units

Check model for Simscape blocks with ambiguous setting of parameter units.

Description

This check identifies blocks in your model that have an ambiguous setting of parameter units. This situation most often applies to frequency and angular velocity units.

For example, a parameter expected in Hz (1/s) may be specified in the block dialog with unit of rad/s. These units are commensurate, but not directly convertible, and using one instead of the other may result in unexpected conversion factors applied to the numerical value by the block equations. The purpose of the check is to verify that the specified unit matches your design intent.

Available with Simscape.

Results and Recommended Actions

Condition

Recommended Action

This model contains blocks where parameter units are not directly convertible to those expected by the block. After running the check, you get a table of results in the right pane of the Model Advisor window. Each cell in the first column of the table contains a link to the problematic block, and the corresponding cell in the second column contains the name of parameter in question, the expected unit, and the specified unit. Clicking a link highlights the corresponding block in the model.

Double-click the highlighted block, verify the parameter unit setting and correct it, if necessary. Then save and reload the model.

See Also

• Units for Angular Velocity and Frequency

Check for outdated AC source blocks

Check model for AC source blocks that should be updated to the current version of the product.

Description

This check identifies AC source blocks in your model that do not match the latest version of the block in the Simscape block libraries.

Blocks from previous versions may be missing parameters available in the latest version. In this case, simulating the model may produce warnings or unexpected results.

Available with Simscape.

Results and Recommended Actions

Condition

Recommended Action

This model contains outdated AC source blocks. After running the check, you get a list of links to the outdated blocks in the right pane of the Model Advisor window. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Model Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all blocks have been updated to the current Simscape version. If the message says that some of the blocks could not be updated automatically, rerun the check and manually replace the outdated blocks with the latest version from the block library. Alternatively, you can consult the Upgrade Advisor to migrate the model to the latest version of Simscape software.

See Also

• Model Upgrades

Check for dry hydraulic nodes

Check model for hydraulic nodes that are considered dry due to a lack of compliance.

Description

This check identifies hydraulic nodes in a Simscape model that are considered dry due to a lack of compliance.

The presence of dry hydraulic nodes can reduce the solver robustness in complex Simscape models. By adding a hydraulic chamber to a node, you can considerably improve the convergence and computational efficiency of a model. Adding a chamber adds a degree of freedom. By adding a chamber, you replace a complex algebraic constraint (the dry node) with a dynamic constraint. The hydraulic chamber is represented by the Constant Volume Hydraulic Chamber block.

Available with Simscape.

Results and Recommended Actions

Condition

Recommended Action

This model contains hydraulic nodes that are considered dry due to a lack of compliance. After running the check, you get a table of results in the right pane of the Model Advisor window. The first column lists the dry nodes found, with the middle column listing the blocks connected to each dry node. Each cell in the middle column of the table contains a link to the block in question, and the corresponding cell in the third column contains the name of port that connects to the dry node. Clicking a link highlights the corresponding block in the model.

Consider adding one Constant Volume Hydraulic Chamber block to each dry node in the list.

See Also

• Troubleshooting Fluids Simulations (Simscape Fluids)

Simscape Checks Overview

Use these checks to optimize real-time simulation performance of models containing Simscape blocks. The top-level Simscape checks are applicable to all physical models. If you have add-on product licenses, the Simscape checks folder also includes corresponding subfolders, such as Driveline checks or Electronics checks. Each of the subfolders contains checks that target specific blocks from that add-on product. If your model contains blocks from an add-on product, run the checks in the respective subfolder in addition to the top-level Simscape checks.

See Also

• Improve Simulation Performance Using Performance Advisor

Check Simscape Solver Configuration block settings

Check model for Solver Configuration blocks with settings that are suboptimal for real-time simulation.

Description

This check identifies Solver Configuration blocks in your model where settings are suboptimal for real-time simulation.

For optimal results, Solver Configuration blocks should have the following options selected: Use local solver and Use fixed-cost runtime consistency iterations.

Available with Simscape.

Results and Recommended Actions

Condition

Recommended Action

This model contains Solver Configuration blocks that do not use local solver or fixed-cost runtime consistency iterations. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic Solver Configuration block. The corresponding cells in the second and third columns contain the current setting for Use local solver and Use fixed-cost runtime consistency iterations, respectively. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. Alternately, double-click the highlighted block, select the Use local solver and Use fixed-cost runtime consistency iterations check boxes, verify the Sample time parameter value and correct it, if necessary. Then save and reload the model. After updating the blocks, either manually or automatically, rerun the check. If the check passes, the table of results contains links to all the Solver Configuration blocks in the model, along with the local solver Sample time parameter value for each block. Check these values for consistency.

See Also

• Solver Configuration

Check Fluid dynamic compressibility option

Check model for blocks with Fluid dynamic compressibility settings that are suboptimal for real-time simulation.

Description

This check identifies blocks in your model where the Fluid dynamic compressibility parameter setting is suboptimal for real-time simulation. This parameter exists in Thermal Liquid blocks, such as pipes and energy converters.

For optimal results, Fluid dynamic compressibility should be set to Off.

Available with Simscape.

Results and Recommended Actions

Condition

Recommended Action

This model contains Thermal Liquid blocks that account for fluid dynamic compressibility. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column contains the current setting for the Fluid dynamic compressibility parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all blocks with a Fluid dynamic compressibility option have been updated.

See Also

• Modeling Thermal Liquid Systems

Electrical Checks Overview

Use these checks to optimize real-time simulation performance of your Simscape Electrical™ model. These checks target specific Simscape Electrical blocks. Run these checks in addition to the top-level Simscape checks, which are applicable to all physical models.

See Also

• Improve Simulation Performance Using Performance Advisor

Check Model dynamics option

Check model for blocks with Model dynamics settings that are suboptimal for real-time simulation.

Description

This check identifies blocks in your model where the Model dynamics or Dynamics parameter setting is suboptimal for real-time simulation. This parameter exists in several types of blocks, and the drop-down options vary between block types. For optimal results, the option that corresponds to not modeling the dynamics should be selected in all cases:

• For switches, Voltage-Controlled Oscillator, DC-DC Converter — No dynamics

• For Accelerometer, Gyro, Pressure Transducer blocks — No dynamics - Suitable for HIL

Available with Simscape Electrical.

Results and Recommended Actions

Condition

Recommended Action

This model contains blocks with dynamics modeling enabled. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column contains the current setting for the Model dynamics or Dynamics parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all blocks with a Model dynamics option have been updated.

See Also

• Accelerometer (Simscape Electrical)

• DC-DC Converter (Simscape Electrical)

• DPDT Switch (Simscape Electrical)

• DPST Switch (Simscape Electrical)

• Gyro (Simscape Electrical)

• Pressure Transducer (Simscape Electrical)

• SPDT Switch (Simscape Electrical)

• SPST Switch (Simscape Electrical)

• Voltage-Controlled Oscillator (Simscape Electrical)

Check Noise mode option

Check model for blocks with Noise mode settings that are suboptimal for real-time simulation.

Description

This check identifies blocks in your model where the Noise mode parameter setting is suboptimal for real-time simulation. This parameter exists in blocks that can generate thermal noise, such as resistors and electrical sources, and you can enable or disable this option. Simulating with noise enabled slows down simulation. For optimal results, Noise mode should be set to Disabled.

Available with Simscape Electrical.

Results and Recommended Actions

Condition

Recommended Action

This model contains blocks where thermal noise generation is enabled. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column contains the current setting for the Noise mode parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all blocks with a Noise mode option have been updated.

See Also

• Current Source (Simscape Electrical)

• Resistor (Simscape Electrical)

• Voltage Source (Simscape Electrical)

Check Parasitic ground conductance

Check model for blocks with Parasitic ground conductance settings that are suboptimal for real-time simulation.

Description

This check identifies blocks in your model where the Parasitic ground conductance parameter setting is suboptimal for real-time simulation. Simulating with noise enabled slows down simulation. For optimal results, Parasitic ground conductance should be set to 0.

Available with Simscape Electrical.

Results and Recommended Actions

Condition

Recommended Action

This model contains blocks with nonzero values for Parasitic ground conductance. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column contains the current setting for the Parasitic ground conductance parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all blocks with a Parasitic ground conductance parameter have been updated.

See Also

• Floating Neutral (Three-Phase) (Simscape Electrical)

• Neutral Port (Three-Phase) (Simscape Electrical)

Check Resolver parameterization option

Check model for Resolver blocks with Parameterization settings that are suboptimal for real-time simulation.

Description

This check identifies Resolver blocks in your model where the Parameterization parameter setting is suboptimal for real-time simulation. For optimal results, Parameterization should be set to Specify transformation ratio and omit dynamics.

Available with Simscape Electrical.

Results and Recommended Actions

Condition

Recommended Action

This model contains Resolver blocks where the Parameterization setting is other than Specify transformation ratio and omit dynamics. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column contains the current setting for the Parameterization parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all Resolver blocks have been updated.

See Also

• Resolver (Simscape Electrical)

Check Simulation mode option

Check model for blocks with Simulation mode settings that are suboptimal for real-time simulation.

Description

This check identifies blocks in your model where the Simulation mode parameter setting is suboptimal for real-time simulation. This parameter exists in two types of blocks:

• Pulse-width modulated (PWM) actuators and drivers, such as H-Bridge, where you can choose between PWM and Averaged modes.

• Stepper motors and drivers, where you can choose between Stepping and Averaged modes.

For optimal results, Simulation mode should be set to Averaged.

Available with Simscape Electrical.

Results and Recommended Actions

Condition

Recommended Action

This model contains blocks where the Simulation mode parameter setting is other than Averaged. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column contains the current setting for the Simulation mode parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all blocks with a Simulation mode option have been updated. After updating the blocks, verify that parameters specific to the Averaged option (for example, Step rate sensitivity) have suitable values.

See Also

• Controlled PWM Voltage (Simscape Electrical)

• Generic Linear Actuator (Simscape Electrical)

• Generic Rotary Actuator (Simscape Electrical)

• H-Bridge (Simscape Electrical)

• Stepper Motor (Simscape Electrical)

• Stepper Motor Driver (Simscape Electrical)

• Unipolar Stepper Motor (Simscape Electrical)

• Unipolar Stepper Motor Driver (Simscape Electrical)

Check Transmission Line blocks

Check model for Transmission Line blocks with Model type settings that are suboptimal for real-time simulation.

Description

This check identifies Transmission Line blocks in your model where the Model type parameter setting is suboptimal for real-time simulation. For optimal results, Model type should be set to Delay-based and lossless. This option is the most efficient numerically, because the other options need multiple segments (typically several tens of segments) to get reasonable accuracy.

Available with Simscape Electrical.

Results and Recommended Actions

Condition

Recommended Action

This model contains Transmission Line blocks where the Model type setting is other than Delay-based and lossless. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column contains the current setting for the Model type parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all Transmission Line blocks have been updated. After updating the blocks, verify that parameters specific to the Delay-based and lossless option (such as Transmission delay and Characteristic impedance) have suitable values.

See Also

• Transmission Line (Simscape Electrical)

Check Zero sequence

Check model for Simscape Electrical blocks with Zero sequence settings that are suboptimal for real-time simulation.

Description

This check identifies blocks in your model where the Zero sequence parameter setting is suboptimal for real-time simulation. These parameters exist in multiple blocks in the Machines library. For optimal results, set the Zero sequence option to Exclude.

Available with Simscape Electrical.

Results and Recommended Actions

Condition

Recommended Action

This model contains blocks where the Zero sequence parameter has a value of Include. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column contains the current setting for the Zero sequence parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all blocks with a suboptimal Zero sequence value have been updated.

See Also

• Electromechanical (Simscape Electrical)

Fluids Checks Overview

Use these checks to optimize real-time simulation performance of your Simscape Fluids™ model. These checks target specific Simscape Fluids blocks. Run these checks in addition to the top-level Simscape checks, which are applicable to all physical models.

See Also

• Improve Simulation Performance Using Performance Advisor

Check Valve opening dynamics option

Check model for valve blocks with Opening dynamics settings that are suboptimal for real-time simulation.

Description

This check identifies blocks in your model where the Opening dynamics parameter setting is suboptimal for real-time simulation. This parameter exists in several directional and pressure control valves. By default, these valve models do not include opening dynamics. For optimal results, Opening dynamics should be set to Include valve opening dynamics. This option avoids instantaneous area changes, which is important in simulations with the local solver, and provides continuous behavior that is more physically realistic.

Available with Simscape Fluids.

Results and Recommended Actions

Condition

Recommended Action

This model contains valves with opening dynamics modeling disabled. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column indicates the current setting for modeling the valve opening dynamics. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all blocks with an Opening dynamics option have been updated.

See Also

• Check Valve (Simscape Fluids)

• Hydraulically Operated Remote Control Valve (Simscape Fluids)

• Pilot-Operated Check Valve (Simscape Fluids)

• Pressure Compensator (Simscape Fluids)

• Pressure Reducing 3-Way Valve (Simscape Fluids)

• Pressure Reducing Valve (Simscape Fluids)

• Pressure Relief Valve (Simscape Fluids)

• Shuttle Valve (Simscape Fluids)

Driveline Checks Overview

Use these checks to optimize real-time simulation performance of your Simscape Driveline™ model. These checks target specific Simscape Driveline blocks. Run these checks in addition to the top-level Simscape checks, which are applicable to all physical models.

See Also

• Improve Simulation Performance Using Performance Advisor

Check Gear friction model option

Check model for gear blocks with Friction model settings that are suboptimal for real-time simulation.

Description

This check identifies gear blocks in your model where the Friction model parameter setting is suboptimal for real-time simulation. This parameter exists in all gears, and the drop-down options vary between blocks. For optimal results, the option that corresponds to not modeling the friction losses should be selected in all cases:

• For Worm Gear, Sun-Planet Worm Gear, and Leadscrew blocks — No friction losses – Suitable for HIL simulation

• For all other gears — No meshing losses – Suitable for HIL simulation

This check does not apply to thermal variants of gear blocks, because these variants always model friction losses.

Available with Simscape Driveline.

Results and Recommended Actions

Condition

Recommended Action

This model contains gear blocks where modeling of the friction or meshing losses is enabled. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column contains the current setting for the Friction model parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all gear blocks with a friction losses option have been updated.

See Also

• Gears (Simscape Driveline)

Check Tire compliance option

Check model for tire blocks with Compliance settings that are suboptimal for real-time simulation.

Description

This check identifies tire blocks in your model where the Compliance parameter setting is suboptimal for real-time simulation. This parameter exists in all tire blocks and specifies whether the model includes longitudinal stiffness and damping. For optimal results, Compliance should be set to No compliance – Suitable for HIL simulation.

Available with Simscape Driveline.

Results and Recommended Actions

Condition

Recommended Action

This model contains tire blocks where the model includes longitudinal stiffness and damping. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column indicates the current setting for the Compliance parameter. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all tire blocks with a compliance option have been updated.

See Also

• Tire (Friction Parameterized) (Simscape Driveline)

• Tire (Magic Formula) (Simscape Driveline)

• Tire (Simple) (Simscape Driveline)

Check Engine time constant option

Check model for Generic Engine blocks with Engine time constant settings that are suboptimal for real-time simulation.

Description

This check identifies Generic Engine blocks in your model where the Engine time constant parameter setting is suboptimal for real-time simulation. This parameter lets you model engine dynamics, that is, the time lag of the engine response. For optimal results, Engine time constant should be set to No time constant – Suitable for HIL simulation.

Available with Simscape Driveline.

Results and Recommended Actions

Condition

Recommended Action

This model contains Generic Engine blocks where the model includes the time lag of the engine response. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column indicates the current setting for modeling the engine dynamics. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all the Generic Engine blocks with an Engine time constant option have been updated.

See Also

• Generic Engine (Simscape Driveline)

Check Dog clutch model option

Check model for dog clutch blocks with Torque transmission model settings that are suboptimal for real-time simulation.

Description

This check identifies blocks in your model where the Torque transmission model parameter setting is suboptimal for real-time simulation. This parameter exists in all blocks that let you model a dog clutch, such as Dog Clutch, Synchronizer, and Double-Sided Synchronizer. The parameter controls whether the torque transmission model accounts for backlash, torsional compliance, and contact forces between ring and hub teeth. For optimal results, Torque transmission model should be set to Friction clutch approximation - Suitable for HIL and linearization, which models clutch engagement simply as a friction phenomenon between the ring and the hub.

Available with Simscape Driveline.

Results and Recommended Actions

Condition

Recommended Action

This model contains dog clutch blocks where the torque transmission model accounts for backlash and other special effects. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column indicates the current torque transmission model setting. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all the blocks with a Torque transmission model option have been updated.

See Also

• Dog Clutch (Simscape Driveline)

• Double-Sided Synchronizer (Simscape Driveline)

• Synchronizer (Simscape Driveline)

Check Losses model option

Check model for Variable Ratio Transmission blocks with Losses model settings that are suboptimal for real-time simulation.

Description

This check identifies Variable Ratio Transmission blocks in your model where the Losses model parameter setting is suboptimal for real-time simulation. This parameter specifies how to implement friction losses from nonideal torque transfer. For optimal results, Losses model should be set to No losses – Suitable for HIL simulation.

Available with Simscape Driveline.

Results and Recommended Actions

Condition

Recommended Action

This model contains Variable Ratio Transmission blocks where the torque transmission model accounts for friction losses from nonideal torque transfer. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column indicates the current setting for modeling the friction losses. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all Variable Ratio Transmission blocks with a Losses model option have been updated.

See Also

• Variable Ratio Transmission (Simscape Driveline)

Check Model transmission lag option

Check model for Torque Converter blocks with Model transmission lag settings that are suboptimal for real-time simulation.

Description

This check identifies Torque Converter blocks in your model where the Model transmission lag parameter setting is suboptimal for real-time simulation. This parameter specifies how to model transmission lag from input to output driveshaft. For optimal results, Model transmission lag should be set to No lag – Suitable for HIL simulation.

Available with Simscape Driveline.

Results and Recommended Actions

Condition

Recommended Action

This model contains Torque Converter blocks where torque is transferred with a time lag. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column indicates the current setting for modeling the transmission lag. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all Torque Converter blocks with a Model transmission lag option have been updated.

See Also

• Torque Converter (Simscape Driveline)

Check Hard stop model option

Check model for blocks with Hard stop model settings that are suboptimal for real-time simulation.

Description

This check identifies Shock Absorber and Torsional Spring-Damper blocks in your model where the Hard stop model parameter setting is suboptimal for real-time simulation. This parameter controls whether the model includes hard stops. For optimal results, Hard stop model should be set to No hard-stops — Suitable for HIL simulation, which eliminates the hard stop force contribution and enhances simulation speed.

Available with Simscape Driveline.

Results and Recommended Actions

Condition

Recommended Action

This model contains Shock Absorber or Torsional Spring-Damper blocks with hard stops. After running the check, you get a table of results in the right pane of the Performance Advisor window. Each cell in the first column of the table contains a link to the problematic block. The corresponding cell in the second column indicates the current hard stop model setting. Clicking a link highlights the corresponding block in the model.

To update the blocks, scroll down the right pane of the Performance Advisor window and click the Update button. If the automatic update is successful, the Result box displays a message that all the blocks with a Hard stop model option have been updated.

See Also

• Shock Absorber (Simscape Driveline)

• Torsional Spring-Damper (Simscape Driveline)

Check and update outdated Simscape Physical Signal blocks

Check model for Physical Signal blocks that should be updated to the current version of the product.

Description

This check identifies Physical Signal blocks in your model that do not match the latest version of the block in the Simscape block libraries. Blocks from previous versions do not propagate physical signal size and units.

Available with Simscape.

Results and Recommended Actions

Condition

Recommended Action

This model contains legacy Simscape Physical Signal blocks that do not propagate units. After running the check, you get a list of links to the outdated blocks in the right pane of the Upgrade Advisor window. Clicking a link highlights the corresponding block in the model. The links can be divided in multiple groups: The first group contains outdated blocks that can be updated automatically, if any. The Upgrade link under this group converts all these blocks to the latest version. Sometimes the legacy blocks cannot be converted automatically because direct conversion will result in a compilation error or a different answer. These blocks are listed in a table, grouped by the underlying issue. Each row of the table contains: A list of links to blocks affected by the issue Issue description Switch to new version link

To update the blocks: If the model contains outdated blocks that can be updated automatically, click the Upgrade link under the list of block links. If the message says that some of the blocks, when switched to propagate signal units, will result in a compilation error or different answer, review the table that groups the blocks based on the underlying issue. For each table row, click the Switch to new version link to convert all blocks listed in the first cell of this row, and then visit the affected blocks individually to resolve the issue.

See Also

• Model Upgrades

• Upgrading Models with Legacy Physical Signal Blocks

Check usage of Simscape event variables with unspecified priority

Check model for event variables with unspecified priority that can affect initialization results.

Description

This check identifies custom components in your model that have event variables declared with unspecified priority and used outside of a when clause. This situation can affect model initialization results.

Prior to R2019b, event variables were not part of the initial solve and event variable targets always had high priority. Now, event variables are treated the same as any other type of variables during initial solve. Therefore, their default priority is none, and you might have to explicitly declare them as high-priority to achieve the previous model behavior during initialization.

Available with Simscape.

Results and Recommended Actions

Condition	Recommended Action
This model contains custom components with event variables that are: Declared with unspecified priority Used outside of a when clause After running the check, you get a table of results in the right pane of the Upgrade Advisor window. Clicking a link highlights the corresponding block in the model. The results also point to the location of the variable declaration in the source code.	To update the model, inspect variables flagged by the check in the Variable Viewer. For variables that initialize to a value other than the target, change the priority to high, either in the underlying source code or in the Variables section of the block interface.

See Also

• Model Upgrades

• Block-Level Variable Initialization

• variables

Check integration method used by 'auto' solver for Simscape DAEs

Check and update the integration method used when a model containing Simscape Differential Algebraic Equations (DAEs) is configured with Simulink^® VariableStepAuto solver.

Description

This check identifies models containing Simscape DAEs and configured with VariableStepAuto solver, which uses ode23t as the integration method. Starting in R2021a, if your model contains Simscape DAEs, auto solver defaults to daessc.

In previous releases, the default VariableStepAuto solver for such models was ode23t. If you open an existing model saved with VariableStepAuto, the solver selection does not change automatically. Use this check to identify models that still use ode23t as variable-step auto solver and update them to use daessc, which is designed specifically for physical modeling.

Available with Simscape.

Results and Recommended Actions

Condition

Recommended Action

This model was saved with VariableStepAuto solver prior to R2021a, it contains Simscape DAEs and uses ode23t as variable-step auto solver. Starting in R2021a, the recommended variable-step auto solver for such models is daessc.

To update the model, click the Update button. If the automatic update is successful, the Result box displays a message that the model has been updated to use daessc integration algorithm when simulating Simscape DAEs with variable-step auto solver. daessc solver tends to be more robust for most Simscape models, but a few models may experience adverse effects due to this change. After updating the model, simulate it and validate the results and performance. If you decide that you want to restore the previous simulation behavior, change the Solver model configuration parameter from auto (Automatic solver selection) to ode23t (mod.stiff/Trapezoidal).

See Also

• Model Upgrades

• Choose a Solver

• Making Optimal Solver Choices for Physical Simulation

Check Simscape use of state-based consistency tolerances

Check that Simscape networks use state-based absolute and relative consistency tolerances during initialization.

Description

This check identifies models where the Consistency tolerance parameter of the Solver Configuration block has a numeric value, which means that the block uses a nonlinear solver based on the equation residual tolerance to initialize the model.

Starting in R2022b, new models use state-based absolute and relative consistency tolerances during initialization. This method provides better robustness and efficiency, especially if used in conjunction with scaling the model by nominal values.

If you open a model created prior to R2022b, the consistency tolerance computation method does not change automatically. Use this check to identify models that still use residual-based consistency tolerance during initialization and update them to use state-based absolute and relative consistency tolerances.

Available with Simscape.

Results and Recommended Actions

Condition

Recommended Action

This model contains a physical network, or multiple networks, where the Solver Configuration block has a numeric value. These networks use residual-based consistency tolerance during initialization. The state-based consistency tolerance computation method, introduced in R2022b, provides better robustness and efficiency, especially if used in conjunction with scaling the model by nominal values. After running the check, you get a list of networks using residual-based tolerance in the right pane of the Upgrade Advisor window. Clicking a link highlights the corresponding block in the model.

To update the model, click the Upgrade to using state-based tolerances button. The Upgrade Advisor updates the listed Solver Configuration blocks to use the default Consistency tolerance and Tolerance factor parameter values. The Result box displays a message that the model has been updated to use state-based consistency tolerances during initialization. After the upgrade, you can use the Solver Configuration block dialog box to adjust the parameter values, as needed.

See Also

• Solver Configuration