1 Assumptions and Requirements

Before discussing the methodology of this form of CAN autobaud, it is important to note which circumstances will allow this method to work. Namely, this method is exclusively for applications in which the baud rate of the CAN bus that is being connected to is one of several standard predetermined values, rather than a completely unknown value. This method of automatic bit rate detection can determine that the device is configured to a different bit rate than its connected CAN bus, but cannot directly determine the correct bit rate. Connecting and automatically adjusting to a bit rate outside of a predetermined is possible, but requires more complex methods and is outside the scope of this document.

In addition, in order for this method to properly function, there must be at least two other devices already communicating on the CAN bus that the application intends to connects to. This is because the application cannot acknowledge incoming CAN messages while it is determining the baud rate of the bus. Hence, without two other devices on the bus, a node using the automatic baud rate method will not be able to receive a complete valid message.