Main Content

Global variables

Customize generated global variable identifiers

Model Configuration Pane: Code Generation / Identifiers


Customize automatically-generated global variable identifiers. This parameter does not affect global variables that the code generator generates for storage classes and services.


This parameter:

  • Appears only for ERT-based targets.

  • Requires Embedded Coder® when generating code.


$R$N$M (default) | string

Enter a macro that specifies whether, and in what order, certain text is to be included in the generated identifier. The macro can include a combination of the following format tokens.


Insert name-mangling text if required to avoid naming collisions.



Insert name of object (block, signal or signal object, state, parameter or parameter object) for which identifier is being generated.


Insert root model name into identifier, replacing unsupported characters with the underscore (_) character.

Required for model referencing.


Insert text that you specify for the $U token. Use the Custom token text parameter to specify this text.


  • Avoid name collisions in general. One way is to avoid using default block names (for example, Gain1, Gain2...) when your model has many blocks of the same type.

  • Where possible, increase the Maximum identifier length to accommodate the length of the identifiers you expect to generate. Reserve at least three characters for name-mangling text.

  • To control the case (upper or lower case) of the text that each token represents, include decorators such as [U_] in your macro. See Control Case of Identifiers by Using Basic Token Decorators.

  • If you specify $R, the value you specify for Maximum identifier length must be large enough to accommodate full expansions of the $R and $M tokens.

  • When a name conflict occurs between an identifier within the scope of a higher-level model and an identifier within the scope of a referenced model, the code generator preserves the identifier from the referenced model. Name mangling is performed on the identifier in the higher-level model.

  • This parameter setting only determines the name of objects, such as signals and parameters, if the object is set to Auto.

  • For referenced models, if the Global variables parameter does not contain a $R token (which represents the name of the reference model), code generation prepends the $R token to the identifier format.

    You can use the Model Advisor to identify models in a model referencing hierarchy for which code generation changes configuration parameter settings.

    1. On the Modeling tab, select Model Advisor.

    2. Select By Task.

    3. Run the Check code generation identifier formats used for model reference check.

Recommended Settings

DebuggingNo impact
TraceabilityUse default
EfficiencyNo impact
Safety precautionNo recommendation

Programmatic Use

Parameter: CustomSymbolStrGlobalVar
Type: character vector
Value: valid combination of tokens
Default: $R$N$M

Version History

Introduced before R2006a