Chap 1 : General about industrial Communication Network Slide bài giảng Khái quát về mạng truyền thông trong công nghiệp trường đại học sư phạm kỹ thuật In the early 20th century, the process control systems and the manufacturing systems were designed based primarily on the mechanical technology and with analogue devices. • After the period, the pneumatic control technology and the hydraulic power were introduced. The pneumatic control technology made it possible to control remote systems by a centralized control system. These technologies are still very common.
HCMC UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY OF ELECTRICAL AND ELECTRONIC ENGINEERING Automatic Control Department Mạng truyền thông công nghiệp (Industrial Communication Network) PGS.TS Trương Đình Nhơn Bộ mơn Tự động Điều khiển Email: nhontd@hcmute.edu.vn 0947.03.12.79 Content Historical Overview Hierarchical Levels in Industrial Communication Networks Transmission methods Network Topology ISO/OSI Asi Profibus Ethernet References [1] Hoàng Minh Sơn - Mạng truyền thông công nghiệp – Nhà xuất khoa học kỹ thuật, 2007 [2] Industrial Networks for Communication and Control [3] Các tài liệu kỹ thuật thiết bị điều khiển cơng nghiệp SIEMENS Criteria • Process examination : 50% (paper test, Online submission) • Final oral in group of two (project) : 50% Historical Overview • In the early 20th century, the process control systems and the manufacturing systems were designed based primarily on the mechanical technology and with analogue devices • After the period, the pneumatic control technology and the hydraulic power were introduced The pneumatic control technology made it possible to control remote systems by a centralized control system These technologies are still very common Historical Overview • At the beginning of 1960, a digital computer was for the first time really applied as a digital controller The term direct digital control (DDC) was used to emphasize that the computer IBM process computer installed in the control room at American Oil Co.'s Whiting, Indiana, refinery directly controls the process • In the 1960s, programmable logic controller (PLC) was developed and it replaced the conventional, relay-based controller, having relatively limited control functions Dick Morley on January 1, 1968 Historical Overview • The numerically controlled (NC) machine tool became to be controlled by computers and the robot was developed in this period Milwaukee-Matic-II was first machine with a tool changer (1959) • In mid 70s, the first distributed computer control system (DCCS) was announced by Honeywell as a hierarchical control system with a large number of microprocessors Historical Overview • The installation of distributed control systems in the newly planned plants or replacement of existing analogue or centralized control systems is presently a common decision of enterprise management • The use of local area networks to interconnect computers and automation devices within an industrial automation system has become popular since 1980 What is an Industrial Network? • By definition, an industrial network requires geographical distribution of the physical measurement I/O and sensors or functional distribution of applications What is an Industrial Network? • Most industrial networks transfer bits of information serially Serial data transfer has the advantage of requiring only a limited number of wires to exchange data between devices • With fewer wires, we can send information over greater distances Because industrial networks work with several devices on the same line, it is easier to add a new device to existing systems Presentation layer The presentation layer is responsible for translation, compression, and encryption Presentation layer This provides function call exchange between host operating systems and software layers It defines the format of data being sent and any encryption that may be used, and makes it presentable to the Application layer Examples of services used are listed below: MIDI HTML GIF TIFF JPEG ASCII EBCDIC Application layer The application layer is responsible for providing services to the user Application layer It is employed in software packages which implement clientserver software When an application on one computer starts communicating with another computer, then the Application layer is used The header contains parameters that are agreed between applications This header is often only sent at the beginning of an application operation Examples of services within the application layer include: FTP DNS SNMP SMTP gateways Web browser Network File System (NFS) Summary of layer Summary of layer TCP/IP protocol suite The layers in the TCP/IP protocol suite not exactly match those in the OSI model The original TCP/IP protocol suite was defined as having four layers: host-to-network, internet, transport, and application However, when TCP/IP is compared to OSI, we can say that the TCP/IP protocol suite is made of five layers: physical, data link, network, transport, and application TCP/IP and OSI model Addressing Four levels of addresses are used in an internet employing the TCP/IP protocols: physical, logical, port, and specific Relationship of layers and addresses in TCP/IP Example 1: Physical addresses A node with physical address 10 sends a frame to a node with physical address 87 The two nodes are connected by a link (bus topology LAN) As the figure shows, the computer with physical address 10 is the sender, and the computer with physical address 87 is the receiver 2.86 Example 2: IP addresses Example 2: IP addresses A part of an internet with two routers connecting three LANs Each device (computer or router) has a pair of addresses (logical and physical) for each connection In this case, each computer is connected to only one link and therefore has only one pair of addresses Each router, however, is connected to three networks (only two are shown in the figure) So each router has three pairs of addresses, one for each connection Example 3: Two computers communicating via the Internet The sending computer is running three processes at this time with port addresses a, b, and c The receiving computer is running two processes at this time with port addresses j and k Process a in the sending computer needs to communicate with process j in the receiving computer Note that although physical addresses change from hop to hop, logical and port addresses remain the same from the source to destination Example 3: Two computers communicating via the Internet