MATLAB: Is the “Configure…” button next to the ‘Inline Parameters’ option in a Simulink model’s Configuration Parameters grayed out even when ‘Inline Parameters’ is enabled

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I was looking to make some of my model parameters tunable to generate code using Embedded Coder 6.2 (R2012a).

Normally, one can select the 'Inline Parameters' option and then hit the "Configure…" button next to it to set certain variables (parameters) to have Custom Storage Classes and therefore be exempt from the inlining process in code generation.

When using a configuration set reference instead, the "Configure…" button is always grayed out, no matter what the value of 'Inline Parameters is'.

Is this by design, or is it a bug? Also, are there any ways that I could get around this to make some of my parameters tunable?

Best Answer

This is by design, as configuration set references are independent of a particular model. Therefore, one cannot access model-specific settings in this fashion.

As a workaround, you may use the command-line approach to set storage classes as in the example below. Instead of configuring a workspace object 'x' to be tunable using the unavailable option, you may create a Simulink.Parameter object in the base workspace and change its Custom Storage Class (CSC):

x = Simulink.Parameter;
x.Value = 1.0;
x.RTWInfo.StorageClass = 'ImportedExtern';

In the example above, with an 'ImportedExtern' CSC, you can then create a header file to declare the extern variable 'x':

double x = 1.0;

This header file can be included by adding the following statement in the 'Source File' section of the 'Code Generation --> Custom Code' configuration parameters.

#include "my_header_file.h"

Related Solutions

MATLAB: Do I receive a warning about a parameter’s storage class being defined twice when I build the Simulink model in the Real-Time Workshop

This warning occurs because the storage class for a parameter say "foo" for example, is specified by both the Simulink.Parameter object (in the base workspace) and in an entry in the "Global (tunable) parameters" table for some model. This model may be your main model, or one of the referenced model.

This warning does not indicate that there is something wrong with the model compilation. It is simply there to alert you to the fact that certain settings--those for that variable in the "Global (tunable) parameters" table--are being ignored.

Removing the entry for "foo" from the "Global (tunable) parameters" table in your models should remove the warning.

To do this:

1. Open the relevant model's "Configuration" in the Model Explorer, or open the models "Configuration Parameters" window (Ctrl+E from the model).

2. Go to the "Optimization" section.

3. Press the "Configure" button, which is located to the right of the "Inline parameters" checkbox. This opens the "Model Parameter Configuration" window that includes the table.

4. Select the "foo" entry in the table, and press the "Remove" button.

You will have to find which is the offending model (or models). Your main model is likely it, but referenced models are also a possibility.

Simulink.Parameter variables are not normally available to add to the "Global (tunable) parameters" tables, but it is possible to have entry left over if "foo" was previously defined as a normal MATLAB variable.

MATLAB: Are the sample times obtained in Simulink 7.8 (R2011b) different from those calculated in previous releases for the model with ‘Inline parameters’ unchecked

This is an expected behavior in Simulink 7.8 (R2011b). This has been introduced with the goal of minimizing the sample time propagation changes when toggling the "Inline Parameters" setting in Optimization -> Signals and Parameters.

In previous releases the "Inline Parameters" option was influencing the way heuristic sample times were defined. This was leading to different sample times depending on this "Inline Parameters" option.

If Inline parameters was ON for your model, your model is not affected by this change and you will obtain the same sample time values. If Inline parameters was OFF in your model your sample times may be affected by this change. Typically you may obtain different sample times when source blocks have inherited sample times.

If you prefer the sample time propagation results from R2011a and earlier with Inline parameters OFF, you can ensure the desired sample times by manually specifying them on the affected block. If the block does not have a sample time parameter, use the Signal Specification block to specify sample times on the input or output signal.

The function “checkSampleTimeChangesIn11b”, attached to this solution, can be used to check which blocks in your model may be affected by this change. This function generates a MAT file when run in R2011a or before for storing the sample time data to be used for comparison in R2011b. The MAT file will be named based on the model name (in example, for the model my_model.mdl, the MAT file would be SampleTimeChangesFormy_model.mat).

1) Download the function “checkSampleTimeChangesIn11b” in a folder included in your MATLAB path

2) Open MATLAB R2011a and execute the command:

checkSampleTimeChangesIn11b('my_model');

where my_model is the name of the Simulink model you are analyzing. This command will create the file SampleTimeChangesFormy_model.mat.

3) Open MATLAB R2011b and execute the command again:

check_results = checkSampleTimeChangesIn11b('my_model');

The function will then return a structure array summarizing the differences. Each element of the array is referring to a specific block where there is a difference and contains two main fields R2011b and R2011a. The substructure:

blk = Block path

blkTS = Block sample time

inputPortTs = Input ports sample time

outputPortTS = Output ports sample time

allows you to compare the block sample time changes.

As an example please consider this specific case.

In R2011a or previous releases with "Inline Parameters" setting OFF:

In R2011b or previous releases with "Inline Parameters" setting ON:

As shown in previous images, for some models Simulink would determine this different approach was leading to different sample times depending on the "Inline Parameters" option. If the option was OFF in R2011a the model is subject to sample time changes when moving to R2011b.

By using the function attached to this solution you can obtain an analysis of the changes. As an example the output of the test for the downsample block is reporting the change:

R2011a or before:
             blk: 'ex_model/Probe1'
           blkTs: [0.6667 0]
     inputPortTs: {[0.6667 0]}
    outputPortTs: {[0.6667 0]}
R2011b:
             blk: 'ex_model/Probe1'
           blkTs: [2 0]
     inputPortTs: {[2 0]}
    outputPortTs: {[2 0]}

Best Answer

Related Solutions

MATLAB: Do I receive a warning about a parameter’s storage class being defined twice when I build the Simulink model in the Real-Time Workshop

MATLAB: Are the sample times obtained in Simulink 7.8 (R2011b) different from those calculated in previous releases for the model with ‘Inline parameters’ unchecked

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