Lenze EMF2178IB - Manual (Page 42)

Data transfer
Structure of the CAN telegram
8
l
42 EDSMF2178IB EN 3.0
8 Data transfer
Master and controller communicate with each other by exchanging data telegrams via the
CAN bus.
The user data area of the CAN telegram either contains network management data, process
dataor parameter data (
^ 44).
Different communication channels are assigned to parameter and process data in the
controller:
ƒ Process data are transferred via the process data channel.
ƒ Parameter data are transferred via the parameter data channel.
8.1 Structure of the CAN 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. 8−1 Basic structure of the CAN telegram
I
Tip!
The identifier and the user data will be explained in more detail in this
documentation.
The other signals refer to the transfer characteristics of the CAN telegram
which are not described in this documentation.
For more information please refer to the homepage of the CAN user
organisation CiA (CAN in Automation):
http://www.can−cia.org