EMBEDDED ELECTRONICS INFORMATIVE SITE
The ISO-OSI model for the standardization of communication protocols,defines 7 hierarchical levels for the division of tasks.
To easy understanding, and for the purposes dedicated to embedded field, I'm going to regroup the 7-layer ISO-OSI layers 2, the transmission level and the level information.
In this subdivision the term Canbus is part of the transmission level. In fact Canbus defines how information is transferred, and thus defines:
a) physical layer transmission wired with use of differential lines.
b) defining the packet transmission mainly composed of:
- Identifier -> (11 or 29 bit)
- Data length -> 4 bit
- Data -> 0 - to 8-byte
c) transmitting multicasting, so if a node has to transmit data places them in line.
At this point, there are several protocols that rely more age and experience he described transmissive transmit information.
* DeviceNet -> Protocol industry.
* CANopen -> industrial protocols.
* J1939 -> Protocol automotive.
Differents projects were developed using canbus technology:
AVCanbusLog , sniffer board to logs and analizze canbus messagge.
AVCanModBridge, board to connect automotive to industrial field using Modbus standard.
AVJ1939Recorder, log and save on SDCard/USB the J1939 engine messagge.
AVDashBoard, dashboard for J1939 engine messagge