MilCAN is a higher layer protocol that is applied on top of a a standard CAN network (as specified by ISO 11898) for use in military vehicles.
The MilCAN specification was defined by the International High Speed Data Bus Users Group (IHSDB-UG), formed in 1999. The stated goal of the spec is “To develop, for various application classes in all military vehicles, a common interface implementation specification based on CANbus”.
There are two versions of MilCAN – MilCAN A and MilCAN B.
MilCAN A uses 29 bit identifiers and uses a similar frame format to J1939. MilCAN A defines 1Mbit, 500Kbps, and 250Kbit communication rates. In addition, MilCAN A is:
- Time-triggered, synchronous application protocol over 29bit CAN
- Mission-critical in mind, message transmission is prioritized
- Utilizing a flying master scheme
- Finalized under: MilCAN A specification MWG-MILA-001, Revision 3
- Widely used in armored vehicles
MilCAN B uses 11 bit identifiers, an actual extension of the CANopen application layer, and only allows periodic data to be transmitted via the bus. MilCAN B supports data rates from 10kbps to 1 Mbps.