How to reset a received CAN receive or unpack block

the CAN receive/unpack block stores the last value until it receives a new one. i need to reset or clear the same once its processed. i need to understand whether data available is from a new received frame or from the old one. other than using the timestamp is there another means to do so???

Answer 1

[Snehal]

Hi @Asha,

I see that you are using the CAN receive/unpack blocks in Simulink R2025a and want to understand if the data available is old or recent without using the message timestamp.

You can enable the ‘Output status’ option from the ‘Output ports’ parameter of the CAN receive/unpack block to check if the data available in that block is from a new received frame or from the old one. This parameter outputs the message received status: status is 1 if the block receives a new message and 0 if it does not. A new output port (‘status’) is added to the block once this option is enabled.

Additionally, here are some important points to consider:

1. Avoid relying on just data change checks when tracking if the available data is new or old since values can repeat across messages
2. Unless necessary, resetting the CAN receive/unpack data manually is not suggested

Refer to the following documentation links for further details:

• https://www.mathworks.com/help/rtw/nucleo/ref/canreceive.html
• https://www.mathworks.com/help/vnt/ug/canunpack.html

Hope this helps!