• Specifically developed for computer communications in a factory environment


• 1980 GM decides to begin development of a networking protocol for the high data rates expected, while improving noise immunity. This scheme was expected to provide a common standard for all equipment to simplify integration.


• Problems,

• Difficulties have arisen getting Countries and Vendors to agree on specific standards

• Standards are so broad that they have become very complex and hard to develop hardware and software for, thus driving up the costs

• Versions 2.1 and 2.2 left the application layer under-defined, but a new effort in version 3.0 to define the application layer. This has lead to even higher levels of disagreement.

• The MAP Protocol is not clearly defined in a single document


• In 1985 GM realized that it couldn’t meet its needs for CIM. Only 15% of the 40,000 programmable devices could communicate.


• No single vendor could meet all the needs, and multiple vendors caused communication incompatibilities.