ABSTRACT
In computer-aided manufacturing systems, [29-31] , apart from internation ally standardized communication networks, the M A P and TOP standards take an important position, specifying the communication links required for factory inte grated automation systems. Although it is difficult to present a general architecture o f a MAP/TOP-based distributed, hierarchically organized multicomputer system, the system configuration, shown in Fig. 10, seems to be the most typical one [7] . Also here, like in the distributed computer systems for process plant automation, each functional level requires an adequate communication network. For instance:
• Machinery or control level requires-for interconnection o f sensing, ac tuating, and display elements to their controllers, as wel l as for control lers parameter tuning and set points provision-a real-time bus such as field bus
• Cell or group level requires-for sequencing batch jobs o f similar work pieces o f products, for supervising various material handling, test, and calibration devices-a local area network or a M I N I - M A P
• Shop floor level requires-for interconnection o f device controllers and for data exchange between them-a M A P bus system as a backbone bus to which various devices and bus systems are attached
• Plant level requires-for production scheduling, monitoring and control, as wel l as for test, calibration, and inspection services-interface to the M A P backbone bus
• Enterprise level requires-for exchange o f business and production plan ning data the interface to a TOP bus system and for data exchange wi th the customers, deliverers, and corporate extensions-a wide area network or an interface to public network
Presently, the majority o f commercially available distributed computer sys tems for plant automation use at all communication levels the most internationally standardized networks. This simplifies the problem o f mutual compatibility o f devices delivered by different computer and instrumentation manufacturers, and
