SAE J1939 is a standarised CAN bus protocol. It is commonly used for communication and diagnosis in vehicles.
STW has released several functions to enable problem free operation with SAE J1939 messages and commands.
SAE J1939 uses the 29-bit extended identifiers, as opposed to the 11 bit standard identifiers.
The protocol defines an index called PGN (Parameter Group Number) which is embedded in the 29 bit identifier of the message. A PGN identifies the function of the message and links the data based on the predefined groups. Parameters such as temperature and RPM can be accessed through these messages. A range of PGNs (00FF00h – 00FFFFh) are available, and can be used, for example, for application specific messages.
