CAN

Applicable receivers:  BD970

COM 3 is at 0 to 3.3 V TTL and is multiplexed with CAN. The receive line is also multiplexed with Event 2. The integrator must have a receiver configured to use the CAN port in order to use this port as a serial port. The functionality cannot be multiplexed in real time. The integrator must add a CAN transceiver in order to use the CAN Port.

For development using the I/O board, this com port is already connected to a CAN transceiver. This is labeled CAN on the I/O board. SW4, labeled COM3 HW Xciever Selection, must be set to CAN. There shouldn't be anything connected to TP5, labeled Event 2.

The following figure shows a typical implementation with a 3.3 V CAN transceiver. It also shows a common mode choke as well as ESD protection. A 5 V CAN transceiver can be used if proper level translation is added.