ecan F28035PN receive data problem

Sabina,

This is expected behavior.  CAN is a bi-directional (multi-master) differential asynchronous serial bus.  The CAN data lines are a differential pair, not a separate TX and RX.  The transceiver takes everything on its CAN TX pin and puts it on the bus and the receiver inside the transceiver takes everything on the CAN bus and puts it on the CAN RX pin.  Therefore when your microcontroller transmits a CAN message the signal from the CAN TX is mirrored on CAN RX by the transceiver.  The CAN controller is smart and knows when it is transmitting and ignores the values on the CAN RX pin except for one small exception: the ACK bit.  If you look at both CAN TX and RX at the same time on a scope, you will see one bit near the end of a frame that is different.  This is the ACK bit.  This is created by another device on the bus beside the message transmitter to let the transmitter know that its message was received successfully.  If you remove the monitoring tool from the bus and try to transmit a frame, you will see the bus continuously loaded with traffic because the CAN controller message is not being received successfully (i.e. no ACK bit).  In this case the CAN RX and CAN TX will match up exactly.

Make sense?

Trey