Nontunable Parameter Storage
By default, block parameters are not tunable in the generated
code. When Inline Parameters is off (the default),
the Real-Time Workshop product has control of parameter storage
declarations and the symbolic naming of parameters in the generated
code.
Nontunable parameters are stored as fields within model_P (formerly rtP),
a model-specific global parameter data structure. The Real-Time Workshop product
initializes each field of model_P to
the value of the corresponding block parameter at code generation
time.
When the Inline parameters option is on,
block parameters are evaluated at code generation time, and their
values appear as constants in the generated code, if possible (in
certain circumstances, parameters cannot be inlined, and are then
included in a constant parameter or model parameter structure.)
As an example of nontunable parameter storage, consider the
following model.
The workspace variable Kp sets the gain of
the Gain block.
Assume that Kp is nontunable and has a value
of 5.0. The next table shows the variable declarations and the code
generated for Kp in the noninlined and inlined
cases.
The generated code does not preserve the symbolic name Kp.
The noninlined code represents the gain of the Gain block
as model_P.Gain_Gain.
When Kp is noninlined, the parameter is tunable.
| Inline Parameters | Generated Variable Declaration and Code |
|---|
| Off | struct Parameters_non_tunable_sin { real_T SineWave_Amp;
real_T SineWave_Bias;
real_T SineWave_Freq;
real_T SineWave_Phase;
real_T Gain_Gain;
};
.
.
.
Parameters_non_tunable_sin non_tunable_sin_P = {
1.0 , /* SineWave_Amp : '<Root>/Sine Wave' */
0.0 , /* SineWave_Bias : '<Root>/Sine Wave' */
1.0 , /* SineWave_Freq : '<Root>/Sine Wave' */
0.0 , /* SineWave_Phase : '<Root>/Sine Wave' */
5.0 /* Gain_Gain : '<Root>/Gain' */
};
.
.
.
non_tunable_sin_Y.Out1 = rtb_u *
non_tunable_sin_P.Gain_Gain;
|
| On | non_tunable_sin_Y.Out1 = rtb_u * 5.0;
|
 | Introduction | | Tunable Parameter Storage |  |
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