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Detect loss of tunability


Select the diagnostic action to take when an expression with tunable variables is reduced to its numerical equivalent in the generated code.

Category: Diagnostics


Default: warning for GRT targets | error for ERT targets


Take no action.


Generate a warning.


Terminate simulation or code generation and generate an error.


  • This diagnostic applies only to the following:

    • Simulink.Parameter objects that have a non-Auto storage class

    • Simulink.Parameter objects that have the Auto storage class and are mapped to a non-Auto storage class

    • MATLAB® variables that you map to a non-Auto storage class

  • When the model configuration parameter Default parameter behavior (Simulink Coder) is set to Tunable this diagnostic does not apply to variables with Auto storage class.

  • The default value for Detect loss of tunability for ERT-based targets is error. When you switch from a system target file that is not ERT-based to one that is ERT-based, Detect loss of tunability is set to error. However, you can change the setting of Detect loss of tunability later.

  • If a tunable workspace variable is modified by Mask Initialization code, or is used in an arithmetic expression with unsupported operators or functions, the expression is reduced to its numeric value and therefore cannot be tuned.

Command-Line Information

Parameter: ParameterTunabilityLossMsg
Type: character vector
Value: 'none' | 'warning' | 'error'
Default: 'warning' for GRT targets | 'error' for ERT targets

Recommended Settings

DebuggingNo impact
TraceabilityNo impact
EfficiencyNo impact
Safety precautionerror

See Also

(Simulink Coder)

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