Purpose And Scope

The purpose of this RP is to define a general-purpose serial data communication link that may be utilized in heavy-duty vehicle applications. It is intended to serve as a guide to promote serial data communication compatibility among microcomputer-based modules. The primary use of the general-purpose communications link is to promote data sharing among stand-alone modules to enhance their operation in a cost effective manner. Communication links used to implement functions that require dedicated links between specific modules may deviate from this RP.

The objectives of this RP are to:

1. Minimize hardware cost and overhead.
2. Provide flexibility for expansion and technology advancements with minimum hardware and software impacts on in-place assemblies.
3. Utilize widely accepted electronics industry hardware and protocol to give designers flexibility in parts selection.
4. Provide a high level of electromagnetic systems compatibility.
5. Provide original equipment manufacturers and aftermarket suppliers the flexibility to customize for product individuality and for proprietary considerations.

This RP implements a bi-directional serial communication link among modules containing microcomputers. This RP also defines those parameters of the serial link that relate primarily to hardware and basic software compatibility such as interface requirements, system protocol, and message format. The actual data to be transmitted by particular modules, which is an important aspect of communication compatibility, is not specified in this document. These and other details of communication link implementation and use should be specified in the separate application documents referenced below under References.