Operating point contents checksum mismatch

Diagnostic action to take if model contents checksum does not match contents checksum of initial operating point

Since R2025a

Model Configuration Pane: Diagnostics

Description

The Operating point contents checksum mismatch parameter specifies the diagnostic action to take if the contents checksum of the model does not match the contents checksum of the initial operating point. To simulate from an initial operating point, specify the value of the Initial state parameter as a Simulink.op.ModelOperatingPoint object.

The contents checksum tracks information about the model structure and algorithmic behavior. A contents checksum mismatch indicates that the current model is structurally or algorithmically different from the model that produced the initial operating point. If the contents checksum of the initial operating point does not match the contents checksum of the model, the software cannot completely initialize the model and simulation to the initial operating point. When you set this parameter to warning or none, the software initializes the simulation using as much data from the initial operating point as possible.

Caution

The results of a simulation that initializes incompletely to an initial operating point can differ, sometimes significantly, from the results of an equivalent simulation that runs from the start, without an initial operating point. Significant deviations in simulation results are more likely to occur in the case of a contents checksum than in the case of an interface checksum or using an initial operating point from a different release.

If you need simulation results to match closely or exactly the results of a simulation run without an initial operating point:

• For best results, set this parameter to error.

• If you set this parameter to warning or none, closely analyze the simulation results and reported mismatches.

The software can detect a contents checksum mismatch but cannot determine the effect of the mismatch on the simulation results. Structural and algorithmic differences that can cause a contents checksum mismatch include:

• Adding or removing blocks other than visualization blocks

• Changing the type of solver from variable-step to fixed-step or from fixed-step to variable-step

• Modifying connections between blocks

• Modifying nontunable block parameter values, such as data types, sample times, and dimensions

• Renaming blocks

• Changing the name of a referenced model

• Modifying an S-function in a way that changes the number of states

• Changing an active variant choice

Settings

error (default) | warning | none

error

The software issues an error and terminates the simulation if the model contents checksum does not match the contents checksum of the initial operating point.

Use this setting when you need simulations run from an initial operating point to produce identical results to an equivalent simulation run from the start, without an initial operating point.

warning

The software issues a warning and initializes the simulation using as much operating point data as possible if the model contents checksum does not match the contents checksum of the initial operating point.

To help you evaluate the effect of the contents checksum mismatch on simulation results, additional diagnostics provide information about how the operating point was used to initialize the simulation, including:

• Unused operating point data for blocks with no matching path in the current model

• Blocks in the model that have states but do not correspond to any data in the initial operating point

• Blocks in the model for which operating point data is invalid due to differences in the block type or block configuration

The same information that the diagnostics provide is available in the ModelInfo property of the Simulink.SimulationMetadata object returned with the simulation results.

none

The software does not issue a diagnostic and initializes the simulation using as much operating point data as possible.

To help you evaluate the effect of the contents checksum mismatch on simulation results, the ModelInfo property of the SimulationMetadata object returned with the simulation results includes information about how the simulation was initialized using the operating point data.

Tips

• The interface checksum tracks a collection of model settings, including solver settings and the sample time in the model. An interface checksum mismatch between a model and initial operating point typically has less of an effect on simulation results. To specify the diagnostic action to take when the model interface checksum does not match the interface checksum of the initial operating point, use the Operating point interface checksum mismatch parameter.

• If you use a model operating point from a different release as the initial state for a simulation, the software cannot completely initialize the model and simulation to the operating point. Incomplete initialization can affect simulation results. To specify the diagnostic action to take when the initial operating point was generated in a different release, use the Operating point object from a different release parameter.

Programmatic Use

Parameter: OperatingPointContentsChecksumMismatchMsg

Type: string | character vector

Values: "error" | "warning" | "none"

Default: "error"

Limitations

Setting this parameter to warning or none is not supported in rapid accelerator simulations or simulations deployed using Simulink^® Compiler™.

Version History

Introduced in R2025a