title: On an LAS-integrated soft PLC system based on WorldFIP fieldbus.
abstract: Communication efficiency is lowered and real-time performance is not good enough in discrete control based on traditional WorldFIP field intelligent nodes in case that the scale of control in field is large. A soft PLC system based on WorldFIP fieldbus was designed and implemented. Link Activity Scheduler (LAS) was integrated into the system and field intelligent I/O modules acted as networked basic nodes. Discrete control logic was implemented with the LAS-integrated soft PLC system. The proposed system was composed of configuration and supervisory sub-systems and running sub-systems. The configuration and supervisory sub-system was implemented with a personal computer or an industrial personal computer; running subsystems were designed and implemented based on embedded hardware and software systems. Communication and schedule in the running subsystem was implemented with an embedded sub-module; discrete control and system self-diagnosis were implemented with another embedded sub-module. Structure of the proposed system was presented. Methodology for the design of the sub-systems was expounded. Experiments were carried out to evaluate the performance of the proposed system both in discrete and process control by investigating the effect of network data transmission delay induced by the soft PLC in WorldFIP network and CPU workload on resulting control performances. The experimental observations indicated that the proposed system is practically applicable.
authors: School of Control and Computer Engineering, North China Electric Power University, Changping District, Beijing, 102206, China. liangeng1976@163.com
authors: Geng
authors: G
authors: Liang
authors: Zhijun
authors: Z
authors: Li
authors: Wen
authors: W
authors: Li
authors: Yan
authors: Y
authors: Bai
mesh_terms: D000465:Algorithms; D003195:Computer Communication Networks; D003196:Computer Graphics; D003198:Computer Simulation; D004867:Equipment Design; D007221:Industry / Q000295:instrumentation*; D008128:Logic; D008838:Microcomputers; D012984:Software; D014584:User-Computer Interface