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turboscrew
Senior III
Nov 13, 2018 8:23 PM UTC
Solved

CAN filtering

How does one define the filter for a CAN A message, when the ID is only 11 bits?

If using 16-bit filter, what should be put to the EXTID[17:15]?

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    Tesla DeLorean
    Tesla DeLoreanBest answer
    Guru
    Nov 14, 2018 5:17 AM UTC

    >>What do the EXTID-bits match to?

    Whatever you have on the wire, it is a one-to-one deal, not magic. If it's random crap you're going to need to mask it...

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    5 replies

    Tesla DeLorean
    Guru
    Nov 13, 2018 9:51 PM UTC

    Match = (ID << 5)

    Mask = 0x7FF << 5;

    Let me go find the diagram, I've posted it a bunch of times to older iteration of the forum...

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    Tesla DeLorean
    Guru
    Nov 13, 2018 10:02 PM UTC

    0690X000006CMzsQAG.jpg

    For the identifier list expect you're going to have to exactly match the bit patterns you've enumerated.

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    turboscrew
    Senior III
    Nov 14, 2018 4:33 AM UTC

    Just that CAN A does not have EXTID. CAN A ID is only 11 bits.

    What do the EXTID-bits match to?

    Or maybe one needs to use masking with CAN A?

    Tesla DeLorean
    Tesla DeLoreanBest answer
    Guru
    Nov 14, 2018 5:17 AM UTC

    >>What do the EXTID-bits match to?

    Whatever you have on the wire, it is a one-to-one deal, not magic. If it's random crap you're going to need to mask it...

    Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..
    turboscrew
    Senior III
    Nov 14, 2018 6:01 PM UTC

    As I thought. Thanks for confirmation.