本科毕业生外文文献翻译本科毕业生外文文献翻译学生姓名：***指导教师：***所在学院：信息技术学院专业：通信工程中国·大庆2011 年 5 月[原文]Industrial Ethernet and Intelligent Building 1 Industrial Ethernet the background1.1 Unified field bus standards dashed, the temptation remainsIn 1984 the United States proceed to develop international standards field bus, a few years, the major companies for commercial interests, Field bus standards can not always uniform. Through multiple voting, consultation, in January 2000 announced that the field bus international standards IEC61158 will be eight bus (Prefabs, Interfuse, P-NET, World, etc.)at the same time as international standards (currently has 10 kinds), formed The outcome of a compromise.At the same time, major foreign companies have also launched its own standards, such as LONWORKS, CAN, Japan's Mitsubishi, France Schneider, the current number of bus standards at the same time the situation still exists, they say the openness and interoperability only At the same can be achieved under a bus standard, different standards between the bus is still limited. The interconnection between different bus and can not be guaranteed, so people in their efforts to seek a unified standard field bus, some people have proposed the use of TCP / IP protocol Ethernet.1.2 The demand for system integration（1）industrial automation control integrated enterprise information is China's national policy to create automation and information technology as an example: In the need to change the business processes of the same time, management informationsystems and e-commerce, decentralized network of manufacturers to be integrated, the existing enterprise resource ERP transformed intoWEB-based applications. The current single from the automation of industrial automation, factory automation, to the development of automation systems, the underlying message should be integrated into the upper information online in order to achieve the integration of control as shown in an integrated system.Modern production system for a multi-storey industrial control systems, generally fall into three tiers:• Equipment-testing equipment and connectivity implementing agencies;• Control of the data obtained from the scene equipment, complete the various control, monitoring operating parameters, alarm and historical trend analysis;• Information layer will control the data processing system after spread to the higher level managementnetwork (TCP / IP Ethernet), in order to achieve integrated management of its network structure 。

（2）Intelligent Building of the urban information system integration, the development of digital, intelligent building (including intelligent residential district), has become a digital city's information site, in order to achieve information sharing, the need to achieve control network and information network of vertical integration, that is, Control network and TCP / IP Ethernet integration.As various subsystems and communications equipment at the scene agreement is diversified and integrated these two models must be developed gateways, in order to achieve the conversion agreement and unity, this has increased the complexity of system integration technology and increase costs. It was boldly put forward can use TCP / IP protocol as a unified agreement, the scene of the subsystems and equipment directly from Ethernet to simplify the system integration of technical difficulty, lower costs, so that controlsignals directly from the Ethernet transmission, So the concept of industrial Ethernet has been raised.2 Ethernet and CSMA / CD2.1 EthernetEthernet (Ethernet) 1975 by the United States XEROX company successfully developed, as a passive medium (such as twisted pair, coaxial cable, etc.) to disseminate information, to the history of the spread of electromagnetic waves known as the "Ethernet" (Ether ) To name.1980 by the DEC, INTEL, XEROX jointly launched a three EthernetV2, is the world's first LAN standard. 1983 IEEEE802 Committee DIX EthernetV2 based introduced IEEE803, using the CSMA / CD MAC technology. 802.3 refer to a CSMA / CD networks, and Ethernet DIX EthernetV2 from the standard definition, not strictly in the circumstances, can be called 802.3 LAN, which is Ethernet.To the modern manufacturing industry as an example, its modern manufacturing automation model in Figure .Industrial Ethernet is the commercial application of Ethernet to industrial control systems, the two networks is not essentially different from, the two are compatible.2.2CSMA / CD (Carrier Sense Multiple Access with Collision DetectionMulti-carrier monitoring visit / conflict detection)CSMA / CD are the first improvement comes from CSMA.（1）CSMA (Carrier monitor multiple access): stop trying to send a signal, first of all to monitor bus, to determine whether there is other media, to stop the signal.• If the media is free, you can send;• If the media are in working condition, then wait some try again after the interval, when heard in a busy state media, CSMA There are several different ways to deal with, the availability of interception ofsignal: adhere to non-CSMA, 1 - adhere to CSMA, P -- Consistently CSMA.（2）CSMA / CD to hear not only the first, but also Baiting Bain hair, a bus in the conflict, but once the conflict was detected; they stopped sending the frame, to give up their own frame. In order to know that other stations can also have a conflict, listening to the conflict to the bus station on the spread of a blocking signal interference, informed the bus station in the conflict have taken place, the capacity of this channel will not be sent because the frame was damaged and waste. With the increased network load, the collision would increase the opportunities, network efficiency decreased significantly.3 Industrial Ethernet the existing problemsField Bus is used for industrial control and complex and harsh environment of industrial design at the scene, the system of real-time and response time have strict demands on electricity use of the environment, there are special requirements. Since Ethernet is designed for information andcommunications, industrial control for the existence of the following questions:(1) using Ethernet CSMA / CD Access Protocol, which is a non-deterministic network.The high demand for real-time control systems, this uncertainty will result in the requested information can not convey. The so-called network segment is even shared the same bus network, you can listen to the message sent by the other side, at the same collision regional conflict (a conflict that will impact the region) of workstations and servers to connect the network area. For example, in a collision conflict in the region have a working group (from a server and workstation components multiple), when more than one visit a server workstation, due to the CSMA / CD bound by the same time allowing only a workstation and server Communications, can only wait for the other workstations. Competition for the workstation communication channel so that the communication workstations have delayed, and this extensionWhen the time is uncertain, workstations more competition for communications for the longer this situation known as the load was more severe the longer the waiting time.If in a collision domain, assume that two working groups, in a collision domain, the first work group servers, workstations access to competitive broadband networks (such as 100 M), another working group of all workstations and servers Are in a wait state and can not run. The two working groups to split the original broadband network (100 M), a working group work, must wait for another group, this has not only delayed, and this delay is uncertain. As CSMA / CD have unforeseen delay, particularly in the heavy load, the more real-time data transmission can not be guaranteed. Therefore Ethernet control system must be solved for real-time and uncertainty.(2) Ethernet in reliability than Bus at the scene.Field Bus is designed for industrial control, able to adapt flammable, explosive (such as chemicals, pharmaceuticals), strong interference andother occasions poor environment occasions. Field bus have shielding, grounding and explosion-proof measures, such as Ethernet and the need to address these issues.(3) Field bus specifications on the network segment with a power supply.For all non-self-powered equipment to power and Ethernet does not provide power, the need for additional electricity supply lines.4 feasibility of the application of Industrial EthernetIndustrial Ethernet for industrial control, the above-mentioned problems, with the Ethernet technology development and the implementation of corresponding measures, in fact, and the uncertainty can be made great improvements:(1) Continuously improve Ethernet rate: the rate in recent years Ethernet from 10 Mbps, 100Mbps to 1 000Mbps and has been widely applied. At present 10 Gaps Ethernet has been commercialized, greatly shortening the data transmission time, improve response time, thesystem's real-time and non uncertainties have improved.(2) using Ethernet switch technology: as the work site shared Ethernet channel competition arising from the conflict affected the collision of real-time system and uncertainty, Ethernet switch technology can be used to be improved. Ethernet-based exchange used in Ethernet switch, switch between the port at the same time can create a number of data channels, each connected to a network port, the port frame between the input and output no longer subject to CSMA / CD MAC bound by the agreement. When the system includes a number of working groups, in general so that each group formed a separate network segment, each of the occupation of the exchange network (of) a port (shown in Figure 4 switches are A, B, C, D 4 net), net of most of the time the work is independent, when any two of the need for information exchange network, the switch in two independent network of information between the channel .Once the end of the exchange of information, access is disconnected.This shows that switched Ethernet shared Ethernet can be overcome existing problems: • Switches on each port can connect a network segment; each of the network bandwidth can be exclusive;• switches on each port, the network of access between the independent and isolated, such as the need for inter-network of information and communication, it can temporarily establish an information channel, after the switch isolation, can greatly reduce the probability of conflict To improve the real-time and uncertainty;• switch VLAN technology commonly used to exchange control system can be allocated to the proprietary information, access and bandwidth, thus ensuring the network's busiest time, the control system is still comfortable enough bandwidth to enable Ethernet transmission of real-time information And uncertainty remained largely theoretical level.(3) In some applications to allow the circumstances: try to control network andinformation networks to use separate, in order to avoid real-time data and non-real-time data of the collision, between the industrial site for independent Ethernet network segment, Thereby improving the real-time and uncertainty. In addition, full-duplex technology can be used to reduce network load, and Ethernet + TCP / IP protocol on the basis of a uniform and apply to the industrial field of application-level control measures such as technical specifications. The above measures can be taken so that in some industrial Ethernet military, industrial, civilian areas of the site has been initially applied in the measurement and control. For example, many countries abroad nuclear accelerator as the Ethernet monitoring and control options, in addition automobile assembly line, thin steel production lines and so on a programmed of industrial Ethernet, monitoring and control from the direction of development of the area, the industrial Ethernet will be Monitoring is the future in the field of an important direction of development, but also the corporate-controlled integration and intelligentbuilding systems integration as a best option.(4) Ethernet power supply problem: over the years has been a defect, especially as IP phones, IP cameras, wireless AP, ENC (Ethernet Control System) system and other applications, more people put in Ethernet transmission Data at the same time, send some energy, small network equipment to meet the demand for electricity, power supply network equipment to solve the small state of disorder and the high cost of power supply wiring. So the IEEE 802.3af standard that is called out, has formed an Ethernet-powered international standards, 3 COM, Hawaii, DLINK, and other companies have with 802.3 aft-standard switching products. IEEE 802.3af standard is the core to meet the standards of 802.3 at the same time, by switching to the network terminal equipment to provide 48 V or 24 V power, the power supply to this industrial Ethernet issues have been very good solution, the principle shown in Figure 1.Figure 1 principle of self-powered Ethernet(5) Network of Ethernet: TCP / IP protocol is an open communication protocol. Security issues do not belong to form networks and TCP / IP protocol. Network security is the ultimate concern of the transmission network in the application layer of information security; it is not illegal changes to use. Protect the security of information transmission and either two ways: exclusive and independent access encrypted information. Before a way to let the lack should not be, the latter should not be the way to get the do not know. Ethernet virtual private network switching technology has become a basic network dedicated channel technology, already very mature and widely used. Ethernet can easily access will require isolation from. Internet information is encrypted TCP / IP on the basic nothing to do with the application of information processing methods.Prior to the issue of information is encrypted with information to carry out the use of declassified after treatment. Now basically an open encryption algorithms, do not rely on secret encryption guarantees, but by password (key). Information security key to the final and most important factor is the holder of the password; he kept using the password of course, and means the security communication system is the core.工业以太网与智能建筑1 工业以太网产生的背景1.1 统一现场总线标准成为泡影，诱惑依然1984年美国着手制定现场总线国际标准，若干年以来，世界各大公司为了商业的利益，现场总线标准始终不能统一。