This is not a peer-reviewed article Pp. 1-17 in ISO 11783: An Electronic Communications Protocol for Agricultural Equipment: ASAE Distinguished Lecture # 23, Agricultural Equipment Technology Conference, 7-10 February 1999, Louisville, Kentucky USA. M.L. Stone, K.D. McKee, C.W. Formwalt and R.K. Benneweis, ASAE Publication Number 913C1798 ISO 11783: AN ELECTRONIC COMMUNICATIONS PROTOCOL FOR AGRICULTURAL EOUIPMENT Marvin L. Stone Professor, Oklahoma State University Kevin D. McKee Manager, Electronics Systems Integration, Case Corp. C. William Formwalt Sr. Project Engineer, Deere and Co. Robert K. Benneweis Project Manager, Electronics, Flexi-Coil Ltd. For presentation at the Agricultural Equipment Technology Conference Louisville, Kentucky 7-10 February 1999 Published by ASAE- - the Society for engineering in agricultural, food, and biological systems 2950 Niles Road, St. Joseph, MI 49085-9659 USA The Lecture Series has been developed by the Power and Machinery Division Tractor Committee (PM-47) of ASAE to provide in-depth design resource information for engineers in the agricultural industry. Topics shall be related to the power plant, power train, hydraulic system, and chassis components such as operator environment, tires, and electrical equipment for agricultural or industrial tractors or self-propelled agricultural equipment. ASAE is grateful to Deere & Co. for sponsoring the ASAE Distinguished Lecture Series Table of Contents Introduction ISO 11783 Overvier Components 9 Wiring and Connectors (the Physical Layer). Message Structure (the Data Link Layer) - 29 Bit CAN .. .11 Interconnection Structure (the Network Layer) 11 Addressing, NAMEing, and Initialization 12 Virtual Terminal 12 Task Controlling .12 Tractor and Tractor ECU Messages 14 Messages on the Tractor Bus 14 Diagnostics 4 Design Strategies for Implementation of ISO 11783 14 Fault Management 5 Electromagnetic Compatibility Future 6 Reference ISO 11783: AN ELECTRONIC COMMUNICATIONS PROTOCOL FOR AGRICULTURAL EOUIPMENT uring the past decade, manufacturers of Electronic communications require significantly more agricultural equipment have increasingly turned standardization than was needed in earlier tractor to electronics to provide products with improved implementinterface standards.Notonlymustthephysical functionality,productivity,and performanceto compatibilitybeaddressed,but compatibilityintheway customers. Electronic content in agricultural equipment informationiscommunicated mustbe addressed.To has increased.Anatural consequence ofadding electronic communicateground speedfor example,connectors, components to agricultural equipment has been realization wiring, voltage and current levels, and the methods of of the advantages of allowing the components to signaling information must be compatible. Information can communicate.Ahitchcontrolleron atractor,for example, thenbecommunicated, butagreement must also existwith may communicate with a transmission and engine regard to the encoding of the information and the definition controller to allow optimized performance. Electronic of the information. With ground speed, the units of communications can be used to coordinate machine measurement, precision, definition, and frequency of components, allow information to be shared among measurement must be agreed upon for it to be interpreted. componentsofamachine,andallowcontrol systemstobe An impact of standardizing a communicationprotocolfor distributed across components of amachine.The cost of agricultural equipment is also to standardize the definitions adding communications is a small part of the cost of stand- and representations of variables associated with aloneelectronics, but may add significantly to the agricultural equipment. functionality, productivity, and performance of the The rapid development of interest in precision farming machine. has alsoincreased the need for a standardized electronics The interface between tractor and implement required communicati