How to get unit into A2L for a signal?

Hi,

I have a question regarding how a signal UNIT should be outputted into the A2L file when the code is generated for a AUTOSAR complaint model.

How could I set so my signals get a specific conversion method of my signal. In this example I want to get degC as a Unit of my signal via a COMPU_METHOD declaration in the A2L.

Ex:

/begin MEASUREMENT

/* Name */ NewSigInDegrees

/* Long identifier */ "My information about NewSig"

/* Data type */ FLOAT32_IEEE

/* Conversion method */ CM_degC

/* Resolution (Not used) */ 0

/* Accuracy (Not used) */ 0

/* Lower limit */ -100

/* Upper limit */ 2000

ECU_ADDRESS 0x0000 /* @ECU_Address@NewSigInDegrees@ */

/end MEASUREMENT

/begin COMPU_METHOD

CM_degC /* Name */

"" /* LongIdentifier */

RAT_FUNC /* ConversionType */

"%12.6" /* Format */

"deg C" /* Unit */

COEFFS 0 1 0 0 0 1

/end COMPU_METHOD

Best Regards

Answer 1

[Paras Gupta]

Hi Ulf,

I understand that you're looking to ensure that your signals are represented with a different unit via COMPU_METHOD declaration in an A2L file for an AUTOSAR-compliant model in MATLAB R2019b.

Note that MATLAB R2019b does not provide the option to create a custom definition of 'CompuMethod' and associate that with a measurement/characteristic.

However, as of MATLAB R2022b, you can use the 'coder.asap2.getEcuDescriptions' object to create an information object for your model ans customize it by creating a new 'CompuMethod' and setting it for your desired signals. Please refer to the "Customize an ASAP2 File" example given in the following documentation for more information on the same:

https://www.mathworks.com/help/ecoder/ref/coder.asap2.getecudescriptions.html#mw_90d67819-429f-42de-ad80-bd74600abe3d

The following links can be useful to learn more about ASAP2 Customization:

• get ECU description object - https://www.mathworks.com/help/rtw/ref/coder.asap2.getecudescriptions.html
• add - https://www.mathworks.com/help/rtw/ref/coder.asap2.getecudescriptions.add.html
• find - https://www.mathworks.com/help/rtw/ref/coder.asap2.getecudescriptions.find.html
• set - https://www.mathworks.com/help/rtw/ref/coder.asap2.getecudescriptions.set.html
• export - https://www.mathworks.com/help/rtw/ref/coder.asap2.export.html

Hope this helps.