Hot!CAN bus filter-mask configuration

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matteosabba
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2018/10/19 06:02:06 (permalink)
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CAN bus filter-mask configuration

Hi,
 
I'm trying to develop a "bootloader via CANbus" for a dspic33f; the bootloader is divided in two parts, a desktop application (on my PC) which takes a binary file, sends it via CANbus (in small 8 bytes packages) to the dispic33f on which there is the second part of the bootloader application, which writes another part of the memory with the instructions contained in the binary file.
 
The communication between PC and dispic33f is done via a PEAK usb-can interface, and the desktop application has been developed using PEAK's libraries.  
 
My problem is the following: the bootloader works just fine when I only have two nodes on the bus (the PEAK usb-canbus dongle and the dspic33f) but if there are other nodes on the bus (even only one more), the dspic33f part of the application doesn't work, presenting the error IVRIF from ecan module at some point, causing the bus to go bus-off.
 
What I'd like to know is: supposed I've correctly configured filters and masks to read only CAN-messages with a specific ID (selected to be the ID of messages coming from my PC via the PEAK dongle), shouldn't this imply that the presence of other nodes in the bus should not affect the transreceiver of my dspic33f?
Am I wrong in understanding the filtering mechanism?
 
 
 
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    du00000001
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    Re: CAN bus filter-mask configuration 2018/10/19 08:39:08 (permalink)
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     ... supposed I've correctly configured filters and masks to read only CAN-messages  ...

     
    I currently can't interpret "IVRIF", but (provided that the PEAK software can live with messages not related to the download process and the other unit(s) do/es not occupy the same identifier(s), the download process should not be affected other than eventually slowing down due to the reduced CAN buswidth available.
    Thus your supposition about "correctly configured" might simply be wrong  wink

    PEBKAC / EBKAC / POBCAK / PICNIC (eventually see en.wikipedia.org)
    #2
    BLmicro
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    Re: CAN bus filter-mask configuration 2018/10/19 11:13:41 (permalink)
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    IVRIF: Invalid Message Interrupt Flag bit
     
    Sounds like the added node might be causing enough of a load on the bus to increase propagation or skew to the point your PIC is not able to even translate the message much less determine if it is intended for it based on the filtering in place.
     
    How do you like the PEAK stuff? I'm going the same direction comparing PEAK to the IXXAT offerings, and a few others.
     
    -BL
    #3
    crosland
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    Re: CAN bus filter-mask configuration 2018/10/19 11:22:19 (permalink)
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    Have you inadvertently added extra terminators when adding the extra node(s)?
     
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    du00000001
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    Re: CAN bus filter-mask configuration 2018/10/19 11:25:46 (permalink)
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    "Invalid Message" is somewhat weird - that is unless your further node transmits CAN FD. This might create "issues".

    PEBKAC / EBKAC / POBCAK / PICNIC (eventually see en.wikipedia.org)
    #5
    du00000001
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    Re: CAN bus filter-mask configuration 2018/10/19 11:27:53 (permalink)
    5 (1)
    BTW: in the lower cost segment, I consider the PEAK devices clearly worth the money.

    PEBKAC / EBKAC / POBCAK / PICNIC (eventually see en.wikipedia.org)
    #6
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