DM&P Group DMP EB-3360-852, Руководство пользователя, Страница: 28 / 48

EBOX-336x Series User Manual
DMP Electronics Inc. 28
CANbus information:
In EBOX-336x CANbus Series, serial port (COM4) has been adapted for CANbus use.
And the CANbus is onboard; it doesn't need extra external power.
PIN assignment:
J14: COM - 9-pin D-Sub connector (CANbus)
Pin # Signal Name Pin # Signal Name
1 - - 2 CANL
3 CAN_GND 4 - -
5 - - 6 - -
7 CANH 8 - -
9 - - - - - -
EBOX-336x CANbus Series provide a UART (serial) interface with HOST to communicate,
support CANbus 2.0A and CANbus 2.0B, to work as a UART to CANbus bridge.
The CANbus only requires a minimum of three pins, those three pins are assigned to Ground,
CANH: CAN High is an input of a "high" voltage.
CANL: CAN Low is an input of a "low" voltage.
In computing terms, the communication architecture is subdivided into 7 layers.
Each layer follows a different protocol that is standard. Two standards commonly listed are:
Data frame
CAN network can be configured to work with two different frame formats:
a. Base frame format CAN 2.0A with 11 bits identifier.
b. Extended frame format CAN 2.0B with 11-29 bits identifier.
Standards
ISO 11898 specifies physical and datalink layer. Following two commonly listed CAN physical layer and standards:
a. ISO 11898-2:
This protocol specifies the high-speed at transmission rates of up to 1 Mbit/s.
Supports a cable length of up to 40 meters
b. ISO 11898-3:
This protocol specifies low-speed at transmission rates above 40 kBit/s up to 125 kBit/s.
Support a much longer cable length, 500 to 1000 meters.