MegaPoints Controllers
System2 Relay-8 User Reference
Revision 1
megapointscontrollers.co.uk
Page 14
CAN ID management
The next area down on the main configuration page concerns network parameters. Refer to the
screenshot below and explanation text for details.
1
Auto CAN ID – Normally left selected (default). This will allow the board to
automatically assign its CAN address and if a duplicate is detected may
automatically reassign to a vacant address.
2
The current boards CAN ID. Showed greyed out if auto enabled (default).
Automatic range: The automatic range for the CAN ID is 1 – 9999. If a duplicate is detected and Auto
CAN ID is enabled either this or the other board with a duplicate ID will seek out a vacant CAN ID and
update its configuration. When Auto CAN ID is selected do not expect CAN IDs to be persistent as
they can change without notice. System2 is designed with this in mind and the board CAN ID is not
relevant to operation.
The CAN specification requires all boards to have a unique CAN ID as part of the collision detection
mechanism. Forcing duplicates is a bad idea and will lead to data errors.
Manual CAN ID selection: We must ask why? There’s no possible benefit we can think of, so it’s
included for edge use cases. Not recommended to change this. Manual range is 1000 – 1999.
