I have an EKS-LM4F232 in a CAN network that has a Kvaser USB-CAN interface and a CAN display. The display sends out about 4 messages per second. When all are on the bus, the USB interface sees all the messages generated by the display, as does the EKS. When I send a message out on the CAN bus from the USB interface, the EKS sees it. Now when I power down the display, both the USB interface and the EKS stop seeing messages. When I now send a message out of the USB-CAN interface, I see a chain of bus errors and the USB goes into error-passive mode. It is as if the EKS is not there. I suspect that the EKS is not setting the ACK bit, so the USB interface thinks nobody is out there an just starts retransmitting.
Do I need to do something special to the EKS CAN to avoid this?