ABSTRACT
The evolution o f computer-based instrumentation devices and material han dling facilities-such as PLCs, production planing and monitoring stations, robots, etc. —has enabled new automation concepts in production engineering and manu facturing. For instance, the originally widely used CNC concept has been replaced by modern ones such as the C I M and FMS concepts. Here, the problem o f inter connection o f a large number o f programmable logic controllers, robots, and vari ous intelligent devices dispersed within the factory had to be solved using special communication systems to be developed. This was the main impetus for starting standardization work in the area o f industrial L A N s . Major engineering compa nies, both vendors o f mechanical, electrical and electronic equipment as wel l as the users, have been working for more than one decade on standardization o f fac tory oriented communication technology. The General Motors ' initiative to work on standardization o f a communication system for manufacturing industry was followed by Boeing, Ford, McDonnell-Douglas, General Electric, DuPont, East man Kodak, Hewlett Packard, Texas Instruments, Motorola, Intel, and many oth ers. As a result, two industrial communication standards have been worked out:
• Manufacturing automation protocol ( M A P ) and • Technical office protocol (TOP)
It was realized that the M A P implementation as a backbone bus system, based on a single broadband coaxial cable, could facilitate building integrated manufacturing systems by interconnecting o f existing "automation islands," equipped wi th thousands o f programmable controllers and robots. Fig. 2 shows an