The SAE J1939 documents are intended for light, medium, and heavy-duty vehicles used on or off road as well as appropriate stationary applications which use vehicle derived components (e.g., Generator sets). Vehicles of interest include, but are not limited to: on- and off-highway trucks and their trailers, construction equipment, and agricultural equipment and implements.

The purpose of these documents is to provide an open interconnect system for electronic systems. It is the intention of these documents to allow Electronic Control Units to communicate with each other by providing a standard architecture.

This particular document, SAE J1939-75, describes the parameters and parameter groups that are predominantly associated with monitoring and control generators and driven equipment in electric power generation and industrial applications. Parameters and parameter groups that may be associated with monitoring and control of the power units, such as engines, turbines, etc, that power the generators and driven industrial equipment and which may be applied in on- and off-highway applications, shall be documented in SAE J1939-71.