CAN Data Format
All messages use a 29 bit address, made up as follows:
3 bit priority
These are set by the transmitter. The lower the number the higher the priority.
2 bits for future expansion (currently set as 00)
16 bit data type
If the MSB is <128 then this is a destination specific message, the destination address is given by the LSB (Data Format 1)
If the MSB is >127 this is a broadcast message, the MSB determines the main data type, LSB determines the sub type (Data Format 2)
8 bit source address
The top three bits are the data group, the lower 5 bits are the particular unit within that group. Default values are set on units, these will only need to be changed when there is more than one of a particular unit on the CAN network. Groups are as follows.
1. Data source
3. Data stores
Units are assigned to a group based on their primary function. A data logger will be classed as a data store, even if it has some built in channels.
Default unit numbers are as follows:
Data source group
4. DL1 MK3 / DL1 PRO
Data stores group
A shortened version of the identifier consisting of the 5lsb of the main data type and the 6 lsb of the sub type is also available.
Main data types