Datasheet

235CAN Unit
Programmable
Controllers
CJ1W-CORT21
CAN Unit
Sending and Receiving 11- or 29-bit CAN
messages
The CAN communication protocol is widely used in all kinds
of aplications. Benefits are its high reliabilty, low price and
ease of implementation. But for two CAN devices to under-
stand eachother they must speak the same protocol (lan-
guage). Many implementers of CAN comunication have
made their own protocol. The User Defined CAN Unit has the
possibility to adapt to any protocol by configuration. This
makes it possible to add a PLC and all its opennes, features
and extensions to what was once a proprietary solution.
The Unit can send and receive 11- or 29-bit CAN messages. The iden-
tifier, datalength and data of the CAN message and the way the CAN
message is send (On time, trigger or change) are set buy FINS com-
mands
CAN communication describes only layers 1 and 2, the Physical and
the Datalink Layer. Layer 7, the Application Layer is normally described
in protocol standards like CANopen and DeviceNet.
Monitoring of diesel-engines and drivetrains in trucks and bus
Robot Control
Function
ISO/OSI Reference Model
Layer 7 Application Layer
Layer 3-6
Layer 2 Data Link Layer
Logical Link Control: LLC
Acceptance filtering,
overload notification,
recovery management
Medium Access Control: MAC
Data encapsulation and decapsulation
frame coding, stuffing
medium access management
error detection
error signalling
acknowledgement
serialization, deserialization
Layer 1 Physical Layer
bit encoding / decoding
bit timing
synchronization
11-bit identifier CAN frame
Applications
Arbitration Field
Control
Field
Data Field
CRC
Field
Ack
Field
End of
Frame
INT Bus idle
S
O
F
R
T
R
I
D
E
DLC 0 - 8 bytes 15 bit CRC
r
o11 bit IDENTIFIER
Specifications
Item Classification: Special CPU Unit
CJ1W-CORT21
Unit number 0 to 15
CAN communication Any baud rate can be set
Transmit and receive 11- or 29-bit CAN messages
Transmit messages on time, trigger, or data change
Configuration Status and control words provide straightforward operation.
All configuration data can can be changed on-line by FINS commands.
Up to 640 identifiers can be configured for message filtering.
Up to 640 different identifiers can be configured for transmission.
Y201-EN2-03.book Seite 235 Donnerstag, 30. März 2006 1:52 13