SAE meets ISO: Description of SAE J1939-73 on SAE J1939-21 in ODX 2.2.0 Format (ISO 22901) 2015-01-2878
SAE J1939 is the synonym for a CAN-based in-vehicle network for heavy-duty road-vehicles (trucks and buses) and non-road mobile machinery (NRMM). The SAE J1939 standards collection consists of 18 parts and 2 digital annexes. SAE J1939-21 (Data Link Layer) describes the data link layer using the CAN protocol with 29-bit identifiers, SAE J1939-73 (Application Layer – Diagnostics) includes the specification of diagnostic messages (DMs).
The software components of external test equipment can be described by software interfaces (APIs). ISO 22900 (Modular Vehicle Communication Interface) contains the description of the D-Server that comes with the D-Server API for the diagnostic application and the D-PDU API for the connection to the in-vehicle network (e.g. CAN). ISO 22901-2 (D-PDU API) references SAE J1939-73 and SAE J1939-21 as “Truck and Bus CAN”.
D-Server based external test equipment is powered by data which is described in ODX. ISO 22901 (Open Diagnostic Data Exchange) contains the specification of a data exchange format. ODX databases include the description of communication parameters and diagnostic protocols.
This paper contains a short technical introduction of SAE J1939-21, SAE J1939-73, ISO 22900 and ISO 22901. Its main part describes how SAE J1939-21 and -73 are described in ODX 2.2.0 and used with the MVCI D-Server. It also contains an outlook in the direction of ISO 13209 (Open Test Sequence Exchange Format, OTX) to be used in SAE J1939 environment.