Configuration
General information about the system bus (CAN)
Structure of the CAN data telegram
77
EDBCSXE040 EN 6.0
8.1
General information about the system bus (CAN)
Note!
The information on this chapter will be part of the "CAN Communication
Manual" at a later date.
All Lenze drive and automation systems are equipped with an integrated system bus
interface for the networking of control components on field level.
Via the system bus interface, for instance process data and parameter values can be
exchanged between the nodes. In addition, the interface enables the connection of further
modules such as distributed terminals, operator and input devices or external controls and
host systems.
The system bus interface transmits CAN objects following the CANopen communication
profile (CiA DS301, version 4.01) developed by the umbrella organisation of
CiA
(
C
AN
i
n
A
utomation) in conformity with the
CAL
(
C
AN
A
pplication
L
ayer).
Tip!
For further information visit the homepage of the CAN user organisation CiA
(CAN in Automation): www.can−cia.org.
8.1.1
Structure of the CAN data telegram
Control field
CRC delimit.
ACK delimit.
Start
RTR bit
CRC sequence
ACK slot
End
Identifier
User data
(0 ... 8 bytes)
l
Network management
l
Process data
l
Parameter data
1 bit
11 bits
1 bit
6 bits
15 bits
1 bit
1 bit
1 bit
7 bits
Fig. 8−2
Basic structure of the CAN telegram
Identifier
The identifier determines the priority of the message. Moreover, the following is coded:
ƒ
The CAN node address (device address in the CAN network) of the node which is to
receive the CAN telegram.
See also chapter "Addressing of the parameter and process data objects" (
ƒ
The type of user data to be transferred
