CAN COMMUNICATION SYSTEM: System Description
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.
Scheme 3
| Name | Harness | Description |
|---|---|---|
| DDL1 | Tx Rx | For communications with the diagnostic tool. (CAN-H and CAN-L are used for controlling) |
| DDL2 | K-LINE | For communications with the diagnostic tool. (CAN-H and CAN-L are used for controlling) |
| Diag on CAN | CAN-H CAN-L | For communications with the diagnostic tool. (CAN-H and CAN-L are also used for control and diagnoses.) |
DESCRIPTION
"Diag on CAN" is a diagnosis method which uses the CAN communication line for the communication between the control unit and the diagnostic tool.
Scheme 4
| Component | Description |
|---|---|
| Main line | CAN communication line between splices |
| Branch line | CAN communication line between splice and a control unit |
| Splice | A point connecting a branch line with a main line |
| Termination circuit | Circuit connected across the CAN communication system. (Resistor) |