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Subsystem method arguments

Customize generated function argument names for subsystems and Simulink functions

Model Configuration Pane: Code Generation / Identifiers


Customize generated function argument names for subsystems and Simulink® functions.


This parameter:

  • Appears only for ERT-based targets.

  • Requires Embedded Coder® when generating code.


rt$I$N$M | string

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

  • Insert u if the argument is an input.

  • Insert y if the argument is an output.

  • Insert uy if the argument is an input and output.



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.

Recommended to maximize readability of generated code.


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.

Recommended Settings

DebuggingNo impact
TraceabilityUse default
EfficiencyNo impact
Safety precautionNo recommendation

Programmatic Use

Parameter: CustomSymbolStrFcnArg
Type: character vector
Value: valid combination of tokens
Default: rt$I$N$M

Version History

Introduced in R2009b