[quote userid="529329" url="~/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1417311/tm4c123ge6pz-tm4c123-sending-and-receiving-can-bus-data-abnormally"]Problem engineering CAN bus node has a total of 7, of which 4 controllers are in the CAN bus reception and reception abnormal phenomenon. Grab data on CAN bus, and waveforms as below.[/quote] Hi Skylar, Can you clarify what do you mean "by a total of 7, of which 4 controllers are in....."? Do you mean there are 7 nodes on the CAN network and 4 of them are failing? What is the other three doing? It is hard to believe 4 of them are failing at the same time. There is master slave relationship in a CAN network. Everyone is listening for a message ID using the acceptance filter. If a message is destined for the controller then it will process it or otherwise ignore. [quote userid="529329" url="~/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1417311/tm4c123ge6pz-tm4c123-sending-and-receiving-can-bus-data-abnormally"] [/quote] Is the first image taken from the transceiver? At a high level, it looks fine. What is the number of bytes on the payload? I suppose it is 4 bytes, right? Who sends out the message? Is it one of the three that you said didn't have the problem? [quote userid="529329" url="~/support/microcontrollers/arm-based-microcontrollers-group/arm-based-microcontrollers/f/arm-based-microcontrollers-forum/1417311/tm4c123ge6pz-tm4c123-sending-and-receiving-can-bus-data-abnormally"] They used the oscilloscope for the controller internal cpu to CAN transceiver chip to grab the relevant signal, below is txd signal. [/quote] I'm not clear with your description and neither the scope. Is this the CANTX pin? If this is truly the CANTX signal then it does not look right. I only see the signal go down for a brief period of time twice. Again, please clarify exactly how many failures are seen? What if there are only two nodes on the network. Can the node that fail reception still fail in a two-node network?
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