This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.


Part Number: LAUNCHXL2-RM46
Other Parts Discussed in Thread: HALCOGEN
I have made use of TJA1050 CAN transceivers along with RM46x launchpads.
 Launchpad1 <=> TJA1050 <=> TJA1050 <=> Launchpad2
We are following the CAN Transceiver connections as per the attached schematics.

We are checking the example program given in HALCogen.
Kindly clarify below mentioned points ,
>Is it right to have same CAN TX and CAN RX Ids . In the attached code CAN TX Id & CAN RX Id()
>The DCAN ES register is indicating that the node has entered CAN bus-off state. How can I avoid the node from entering CAN bus-off state?
>Should I enable bit 9 of DCAN CTL register for auto CAN bus on?
  • Hello,

    For CAN communication, both ends of the pair of signal wires (CANH and CANL) must be terminated. The pin1 and pin 2 of J1 shoud be shunted on both boards.

    You can not use the same ID for TX and RX.

    Two or more CAN controllers may start a message at the same time. The conflict is resolved in the following way: The TX nodes monitor the bus while they are sending. If a node detects a dominant level when it is sending a recessive level, it will immediately quit the arbitration process. The arbitration is performed over the whole Arbitration Field and when that field has been sent, exactly one transmitter is left on the bus. 

  • Hi,

    I am a newbie for CAN. I have interfaced the transceiver as per your suggestion. But as per attached screenshots the ID for message box is similar. How do I set different message ID (for Tx and Rx) to obtain the expected results.



  • Hello Joel,

    1. In your configuration, the message ID for CAN1 TX is 1, and other mailbixes are not activated 

    2. The message ID for CAN2 RX is 1 which is receive data from CAN1. Other mailboxes are not activated. If you want CAN2 to TX message, the message ID can be any number (for example 123, 321, etc) but 1 since 1 is used by CAN1 TX mailbox1..