As discussed on the dev call, the physical layer specification for CAN
transports is significantly less mature than the rest of this specification and is
also the most difficult layer to standardize in generic terms. Proper
functioning of the CAN data-link layer requires properly designed
electrical busses with properties specific to the physical
dimensions of a vehicle, the topology of the network, the number of transceivers connected
to the network, the location of the transceivers in relation to each other,
and the electrical properties of each transceiver. As high data-rate
variants like CAN-FD 1/5Mbs are deployed this electrical engineering
will become even more important even for very small CAN busses.
Because of this we are removing the physical layer specification from
the core document but reserve the right to create sibling documents
that standardize physical UAVCAN networks based on vehicle morphology
and supported transports.
As discussed on the dev call, the physical layer specification for CAN transports is significantly less mature than the rest of this specification and is also the most difficult layer to standardize in generic terms. Proper functioning of the CAN data-link layer requires properly designed electrical busses with properties specific to the physical dimensions of a vehicle, the topology of the network, the number of transceivers connected to the network, the location of the transceivers in relation to each other, and the electrical properties of each transceiver. As high data-rate variants like CAN-FD 1/5Mbs are deployed this electrical engineering will become even more important even for very small CAN busses. Because of this we are removing the physical layer specification from the core document but reserve the right to create sibling documents that standardize physical UAVCAN networks based on vehicle morphology and supported transports.