device transfer RS485 to CAN

In the CAN recessive state, the differential voltage can be zero, which is not a valid RS-485 signal level. However, modern RS-485 receivers have built-in fail-safe logic that interprets an undriven bus as logic one, and a bus without such logic is supposed to have fail-safe biasing resistors with the same effect. So it might actually work to wire the buses together so that the CAN dominant state (CANH > CANL) corresponds to RS-485 logical zero (A < B).