Modern telecommunication methods have many impacts on manufacturing, and tele service has become one of the strategic approaches to realize the ideas of a flexible manufacturing system. Monitoring and maintenance of p...Modern telecommunication methods have many impacts on manufacturing, and tele service has become one of the strategic approaches to realize the ideas of a flexible manufacturing system. Monitoring and maintenance of production lines from the remote monitor center is an important application of such techniques. This paper presents a typical model of tele service systems and discusses the underlying challenges. RMMST (remote monitoring and maintenance system testbed), based on PC PLC and their networks which are used widely in production lines, is presented in detail as a concrete example. With the support of digital technique, RMMST can be used in the monitoring and maintenance of remote production lines conveniently.展开更多
The length of data frame is an important parameter in Medium Access Control(MAC) layer protocol. A method of finding the optimal length of data frame when impulsive disturbance is involved in PowerLine Communications ...The length of data frame is an important parameter in Medium Access Control(MAC) layer protocol. A method of finding the optimal length of data frame when impulsive disturbance is involved in PowerLine Communications (PLC) is proposed. Having analyzed the characteristics of impulsive disturbance in powerline and the collision mechanism between the disturbance and data frame, this letter gives the function of the network channel utilization with the length of data frame in MAC layer and the impulsive disturbance. Our stochastic process simulation shows that it is feasible to get the optimal length of data frame.展开更多
可编程逻辑控制器(Programmable Logic Controller,PLC)自动化控制在工业领域的应用十分广泛,基于PLC的网络通信技术是实现控制设备之间信息互联互通的关键和前提。不同类型PLC自动化控制的网络通信技术有所差异,主要技术类型包括点对...可编程逻辑控制器(Programmable Logic Controller,PLC)自动化控制在工业领域的应用十分广泛,基于PLC的网络通信技术是实现控制设备之间信息互联互通的关键和前提。不同类型PLC自动化控制的网络通信技术有所差异,主要技术类型包括点对点接口(Point to Point Interface,PPI)通信、过程现场总线(Process Field Bus,PROFIBUS)通信等。文章简要概述了PLC的特点和运作方法,并在此基础上对PPI、PROFIBUS等基于PLC的网络通信技术进行研究,以供参考。展开更多
文摘Modern telecommunication methods have many impacts on manufacturing, and tele service has become one of the strategic approaches to realize the ideas of a flexible manufacturing system. Monitoring and maintenance of production lines from the remote monitor center is an important application of such techniques. This paper presents a typical model of tele service systems and discusses the underlying challenges. RMMST (remote monitoring and maintenance system testbed), based on PC PLC and their networks which are used widely in production lines, is presented in detail as a concrete example. With the support of digital technique, RMMST can be used in the monitoring and maintenance of remote production lines conveniently.
文摘The length of data frame is an important parameter in Medium Access Control(MAC) layer protocol. A method of finding the optimal length of data frame when impulsive disturbance is involved in PowerLine Communications (PLC) is proposed. Having analyzed the characteristics of impulsive disturbance in powerline and the collision mechanism between the disturbance and data frame, this letter gives the function of the network channel utilization with the length of data frame in MAC layer and the impulsive disturbance. Our stochastic process simulation shows that it is feasible to get the optimal length of data frame.
文摘可编程逻辑控制器(Programmable Logic Controller,PLC)自动化控制在工业领域的应用十分广泛,基于PLC的网络通信技术是实现控制设备之间信息互联互通的关键和前提。不同类型PLC自动化控制的网络通信技术有所差异,主要技术类型包括点对点接口(Point to Point Interface,PPI)通信、过程现场总线(Process Field Bus,PROFIBUS)通信等。文章简要概述了PLC的特点和运作方法,并在此基础上对PPI、PROFIBUS等基于PLC的网络通信技术进行研究,以供参考。