There are 256 CAN objects shared for all EB10 Boards in a controller.  For example when using a 3XL/3XM with EB10, there are 128 CAN objects for the controller Main board + 256 shared CAN objects for expansion boards for a total of 384 CAN objects. (This is the same whether the controller has only 1 or up to 6 EB10 boards, they all share 256 CAN objects)