Книга: Advanced PIC Microcontroller Projects in C

9.9.4 Listen-only Mode 

9.9.4 Listen-only Mode 

The listen-only mode allows the CAN module to receive messages, including messages with errors. It can be used to monitor bus activities or to detect the baud rate on the bus. For automatic baud rate detection, at least two other nodes must be communicating with each other. The baud rate can be determined by testing different values until valid messages are received. The listen-only mode cannot transmit messages.