Dear Dora ,
I don't know exactly what type of test you're doing.
What I can say you for sure is that if you try to send from two different CAN nodes ( master or slave is not a problem on CAN which is multimaster by definition .. ) the very same CAN Identifier at the same time you'll get a CAN error that , potentially , freeze the bus completely . This is because during CAN ID transmission there must be an ID with a higher priority ( lower ID ) that wins the arbitration phase , otherwise the two nodes ( sending the same ID ) will try to send again and again that message without winning arbitration
To avoid that you have to assign at least a differente ID for each node in transmission ..
