徐州工程学院毕业设计(论文)英文原文Development of a monitoring and control platform for PLC-based applicationsS. Dana, A. Sagahyroon , A. Elrayes, A.R. Al-Ali, R. Al-AydiAbstract This paper discusses the design and implementation of a platform to remotely monitor and control PLC-based processes over TCP/IP or by usingthe GSM network. The platform is built using industry-standard off-the-shelf PLCs. Integrated with each PLC are communication processors that canbe used for connectivity to the network and to a GSM modem. The communication processor module (Ethernet module) used in this work, providesan industrial compatible protocol over TCP/IP that achieves the same functionality as Profinet but at a much higher bandwidth (10/100 Mbps).Additionally, a mobile-based communication protocol that facilitates remote monitoring and control of PLCs using SMS messages has also beendeveloped. The intent here is to provide system users with a back-up communication mechanism in case of a network failure. 2007 Elsevier B.V. All rights reserved.1. IntroductionThe recent growth of networks technology and specially thewide spread of the Internet have promoted the development ofdistributed measurement systems for a variety of industrial applications.These distributed measurement systems can be used in the monitoring and control of various instruments in thenetwork 1,2.A Programmable Logic Controller (PLC) is microprocessorbasedcontrol system that can be programmed to sense, activateand control industrial equipment and therefore incorporates anumber of input/output terminals for interfacing to an industrial process. A control program stored in the PLC memory determines the relationship between the inputs and outputs of the PLC. PLCs are intelligent automation stations that possess highly useful and desirable features such as 3: Robustness. High degree of scalability: modern PLC families have a wide spectrum of CPU types that allows easy scalability in functionality and performance. Extensibility: the modular design of PLCs enables the extension with a wide range of digital and analog I/O modules. Also, various integrated technology modules are available for various application areas. Sophisticated communication capabilities: modern PLCs have communication ports that provide for centralized or distributed connectivity. Powerful development environment: modern PLC families come with a cross development environment that support different languages for programmability, allows semigraphical hardware configuration and offer strong debugging mechanisms.Remote access to control and monitor various devices in an industrial setting is of value to engineers and automation facilities. Current implementations of remote PLC monitor and control use dedicated PCs or web servers connected to the PLC. Fig. 1 illustrates a common architecture used in industry. As shown, PLCs are connected to the network through a computer. The PLC system is usually interfaced to this computer using the serial Port or Profibus. These types of systems are disadvantaged by the dedicated use of a PC to access the PLC system. The architecture also does not make use of the advents and strides made in areas such as telecommunications and web technology.In recent years and due to the ever increasing capabilities of PC computing and the influx of network protocols and standards, there has been a surge in the design and implementation of distributed measurement and control systems for industrial applications. Typically, these systems are based on the clientserver architecture while securing communication using the TCP/IP protocol 46. Modern PLCs come with embedded web servers that provide open access to useful real time information and diagnostics that can be viewed via any standard web browser. This remote accessibility provides several advantages over more traditional solutions. For example, a problem can easily be diagnosed and perhaps fixed remotely; also engineers can have remote access to the PLC CPU configuration tools and hence allowing for remote upload/download and configurability via the intranet or internet.In this paper we will discuss the design and implementation of a networked platform for remotemonitoring and control of PLCs. The platformis built around the Siemens S7 series of PLCs. These PLCs have an integrated communication processor that can be used to provide accessibility to the internet. The monitoring and control can be accomplished in a wired or wireless environment, via an intranet or internet hence providing for a complete solution for the remote monitoring and control of industrial processes.We will also discuss the utilization of the GSM network and the operation of a communication protocol that uses SMS messaging to communicate with the PLC stations and a Database Server integrated with the system.The paper is organized as follows: in Section 2 we describe the overall system architecture; section three