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User Manual - QG65D CANopen Dynamic Inclinometer (Type H) V2.3
7. CANopen specification
The QG65D series of devices commun with the CANopen interface according to CiA 301. The device profile CiA 410 is
implemented. All parameters and measured values can be accessed by the Object dictionary. More knowledge of
CANopen sensors can be found in our
Knowledgebase .
7.1. CANopen Communication Objects (COB)
A CANopen device contains a communication module that provides communication objects and the appropriate
functionality to transport data items via the underlying network structure. In other words: objects that you send or
receive from the device for different communication purposes.
The communication objects are described by the services and protocols. Objects we often use:
Common COBs Description
SDO Service Data Object provides direct access to object entries of a CANopen device's object
dictionary
PDO Process Data Object is used to transfer real-time data
NMT Network Management object is used to execute network management services to initialize,
monitor, restart or stop the sensor
SYNC Synchronization object provides the basic network synchronization mechanism
EMCY Emergency object is used to indicate internal errors
Heartbeat Heartbeat is produced by the device to indicate its status. It Is one of the error control
services in CANopen.
LSS Layer Setting Service (LSS) enables the LSS master to modify the LSS slaves’ node -ID and to
switch the entire network from one data rate to another.
Table 12 – Common communication objects
7.2. Predefined CAN-IDs
Every CAN message on the bus starts with a CAN-ID. A CAN device that uses 11-bit identifiers is commonly called
CAN 2.0 A and a CAN device that uses 29-bit identifiers is commonly called CAN 2.0B. For CANopen sensors, DIS
Sensors implements an 11-bit CAN-ID which consists of a 4-bit function code and 7-bit Node ID.
CiA has pre-defined CAN-IDs for common CAN objects as below:
Examples:
Object SYNC has function code 0001b, resulting CAN-ID 000,1000,0000b=080h.
Object TPDO1 has function code 0011b, resulting CAN-ID 001,1000,0000b=180h.