The Class A Task Force of the Vehicle Network for Multiplexing and Data Communications Subcommittee is providing information on sensors that could be applicable for a Class A Bus application. Sensors are generally defined as any device that inputs information onto the bus. Sensors can be an input controlled by the operator or an input that provides the feedback or status of a monitored vehicle function. Although there is a list of sensors provided, this list is not allinclusive. This SAE Information Report is intended to help the network system engineer and is meant to stimulate the design thought process.

Three Classes of Multiplex Networks

The Vehicle Network for Multiplexing and Data Communications Committee has previously identified three classes of vehicle data communication networks.

Class A Multiplexing

Class A Multiplexing contains many of the operator-controlled functions and the monitored vehicle function status inputs. Some examples of sensor inputs would be the operator control of powered convenience features (power window switches) or the status of a fluid level (windshield washer fluid).

Class B Multiplexing

Class B Multiplexing provides the data communications between different modules, internal and external to the vehicle, for the purpose of sharing common data about the vehicle. An example of this is the diagnostic information shared between an internal (on-vehicle) module and an external (hand-held) module for service repair.

Class C Multiplexing

Class C Multiplexing contains systems that require real time, high-speed control, and normally require a significant amount of information to function properly. An example is the wheel speed sensor for the Anti-Lock Brakes System.