The question about the connecting the FlexCan block from NXP with CAN Pack in simulink

edenli · ‎07-11-2017

Hi Guys,

I have a doubt about the FlexCan simulink block from NXP,i wanna use the CAN PACK block with the FlexCAN block ,like as the Can block from TI,shown as below:

becasue the CAN Pack can load the DBC file shown above, we can give the value to the signal,then the eCan Trans block will send the signals out.

but the FlexCan block from NXP seems not connect the CAN PACK block in the simulink,because the dimensional is inconformity.

i have another question how can i send a 12 bit signal using the can block from NXP?

Daniel_Popa · ‎07-11-2017

Hi edenli‌,

I do not have the Vehicle Network Toolbox license - but from the Matlab Help, the CAN PACK is going to output a full CAN frame message.

The NXP CAN block expects only the DATA payload (B7 - B0) (source)

Therefore, you need to de-serialized the message you get from the CAN PACK and extract DATA payload. Then since you need to transmit only 12bits you should keep only B0 and B1, pass it to the CAN Transmit and set up its length input to value 2 instead of 8.

That should to the trick.

Hope this helps!

Daniel

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Daniel_Popa · ‎03-26-2018

Have you fixed the problem ?

ruicui · ‎03-26-2018

Hello Daniel,

No, I haven't. I need to load the dbc first. The output of "CAN Pack" is "CAN message" type. I am not sure how to convert/extract data payload to uint8 type.

I think its possible to import .c/.h which generated by Vector Geny tool, then call the signal function directly from Matlab.

Thanks,

Rui

Daniel_Popa · ‎03-28-2018

Hi Rui,

An example of PACK can be found here: How to Build and Configure a CAN with S32K to Emulate Automotive Body Control Infrastructure in the slave.mld model. (unpack example can be found in master.mdl)

I think its possible to import .c/.h which generated by Vector Geny tool, then call the signal function directly from Matlab.

Yes, there are multiples ways. Please check:

Tip #3: MBD Toolbox - Add custom code to your Simulink model

Tip #5: MBD Toolbox - Use S-Function to call your custom code anywhere in the model

or use Simulink Custom Code blocks

Hope this helps!

Daniel

Daniel_Popa · ‎07-11-2017

Hi edenli‌,

I do not have the Vehicle Network Toolbox license - but from the Matlab Help, the CAN PACK is going to output a full CAN frame message.

The NXP CAN block expects only the DATA payload (B7 - B0) (source)

Therefore, you need to de-serialized the message you get from the CAN PACK and extract DATA payload. Then since you need to transmit only 12bits you should keep only B0 and B1, pass it to the CAN Transmit and set up its length input to value 2 instead of 8.

That should to the trick.

Hope this helps!

Daniel

edenli · ‎07-13-2017

Hi Daniel,

Thank you for your help, Now i have achieved it!

Best Regards!

Eden Li

ruicui · ‎03-09-2018

Hello guys,

How do you de-serialized the message? Simulink doesn't allow me to convert the "CAN message" type. So I can't go to next step and extract data payload from it.

Thanks,

Rui

Daniel_Popa · ‎03-12-2018

Hi Rui Cui,

In case you have the Embedded Coder toolbox you could use the CAN Pack/Unpack blocks.

An example how to use it can be found here: https://community.nxp.com/thread/465130

Hope this helps!

Daniel

ruicui · ‎03-12-2018

Hello Daniel,

Apparently, I didn't explain my question well. My question is similar as Eden Li: I want to load certain dbc first and then use S32K library/blocks to send my CAN message.

However, see following screenshot:

"FCAN_Send" need 8 bytes data. But by using "CAN Pack", the output data type is "CAN message", Matlab doesn't allow me to convert to any type. So I can't extract the data payload and convert to uint8.

Thanks,

Rui Cui