6 structure of the can data telegram, 1 identifier, Identifier – Lenze 8400 StateLine User Manual

Page 496: 11 system bus "can on board

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11

System bus "CAN on board"

11.6

Structure of the CAN data telegram

496

Lenze · 8400 StateLine · Reference manual · DMS 12.0 EN · 06/2014 · TD05/TD14

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11.6

Structure of the CAN data telegram

[11-2] Basic structure of the CAN telegram

The following subchapters provide a detailed description of the identifier and the user data. The

other signals refer to the transfer characteristics of the CAN telegram whose description is not

included in the scope of this documentation.

Tip!
Please visit the homepage of the CAN user organisation CiA (CAN in automation) for further

information:

http://www.can-cia.org

11.6.1

Identifier

The principle of the CAN communication is based on a message-oriented data exchange between a

transmitter and many receivers. All nodes can transmit and receive quasi-simultaneously.
The identifier, also called COB-ID (abbr. for communication object identifier), is used to control

which node is to receive a transmitted message. In addition to the addressing, the identifier

contains information on the priority of the message and the type of user data.
The identifier consists of a basic identifier and the node address of the node to be addressed:
Identifier (COB-ID) = basic identifier + node address (node ID)
Exception: The identifier for process data/heartbeat/emergency objects as well as network

management and sync telegrams is freely assigned by the user (either manually or automatically by

the network configurator), or is permanently assigned.

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