Any device connected to the CANopen network is entirely described by its Object Dictionary. The object
dictionary defines the interface to a device. Within the Object Dictionary, all parameters are assigned a
unique index and sub-index. Thus, all parameters can be uniquely addressed by this pair of numbers.
There are two important text files associated with the Object Dictionary. These are:
EDS (Electronic Data Sheet)
An EDS is a text file representation of the Object Dictionary structure only. It contains no data values.
The EDS is used by configuration software such as Sevcon’s DVT to describe the structure of a node’s
Object Dictionary. An EDS for each Dragon8 model and software version, is available from Sevcon. The
EDS file format is described in the DSP306 – Electronic Data Sheet Specification.
Each Object Dictionary matches a particular Dragon8 software revision, and its structure is hard coded into the
controller software.
DCF (Device Configuration File)
This is a text file similar to an EDS except that it contains data values as well as the Object Dictionary
structure.
DCFs are used to:
• Download a complete pre-defined configuration to a node’s Object Dictionary.
• Save the current configuration of a node’s Object Dictionary for future use.
Network Configuration
General
Use the following procedure to setup the Dragon8 controller on the network:
1. Set node ID and baud rate in 5900h to the required values. Node IDs must be unique, and the
baud rate must be the same for each node.
2. Set SYNC COB-ID in 1005
h
to 0x40000080 for the SYNC producer, or to 0x00000080 for the
SYNC consumers. Bit 30 is set to indicate to a node if it is the SYNC producer. Only one node
in the network should be configured as the SYNC producer. This should normally be the VCU.
On the SYNC producer, set the SYNC rate in 1006
h.
3. Set the EMCY message COB-ID to either 0x00000000 or 0x80 + node ID in 1014
h
. Setting to
0x00000000 will automatically calculate the EMCY COBID from the node ID.
EMCY COB-IDs must be configured correctly to ensure the master handles EMCYs from slaves
correctly.
4. Configure the heartbeat producer rate in 1017
h
. This is the rate at which this node will transmit
heartbeat messages.
5. Configure the heartbeat consumer rate in 1016
h
. A consumer should be configured for each node
to be monitored.
Heartbeats must be configured correctly for correct network error handling. The master node
should monitor heartbeats from all slave nodes. Slave nodes should, at a minimum, monitor
heartbeats from the master node.
Loss of CANbus communication from any one node must cause a heartbeat fault to occur.
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