108 • Fieldbus CommunicationETHERNETWAGO-I/O-SYSTEM 750PROFINET IO4 Fieldbus Communication4.1 ETHERNET4.1.1 GeneralETHERNET is a technology, which has been proven and established as aneffective means of data transmission in the field of information technologyand office communication. Within a short time ETHERNET has also made asuccessful breakthrough in the area of private PC networks throughout theworld.This technology was developed in 1972 by Dr. Robert M. Metcalfe, David R.Boggs, Charles Thacker, Butler W. Lampson, and Xerox (Stanford, Ct.).Standardization (IEEE 802.3) took place in 1983.ETHERNET predominantly uses coaxial cables or twisted pair cables as atransmission medium. Connection to ETHERNET, often already existing innetworks, (LAN, Internet) is easy and the data exchange at a transmission rateof 10 Mbps or for some couplers/controllers also 100 Mbps is very fast.ETHERNET has been equipped with higher level communication software inaddition to standard IEEE 802.3, such as TCP/IP (Transmission ControlProtocol / Internet Protocol) to allow communication between differentsystems. The TCP/IP protocol stack offers a high degree of reliability for thetransmission of information.In the ETHERNET based (programmable) fieldbus couplers and controllersdeveloped by WAGO, usually various application protocols have beenimplemented on the basis of the TCP/IP stack.These protocols allow the user to create applications (master applications)with standardized interfaces and transmit process data via an ETHERNETinterface.In addition to a series of management and diagnostic protocols, fieldbusspecific application protocols are implemented for control of the module data,depending upon the coupler or controller, e. g. MODBUS TCP (UDP),EtherNet/IP, BACnet, KNXNET/IP, PROFINET, Powerlink, Sercos III orothers.Information such as the fieldbus node architecture, network statistics anddiagnostic information is stored in the ETHERNET (programmable) fieldbuscouplers and controllers and can be viewed as HTML pages via a web browser(e.g., Microsoft Internet-Explorer, Netscape Navigator) being served from theHTTP server in the couplers and controllers.Furthermore, depending on the requirements of the respective industrialapplication, various settings such as selection of protocols, TCP/IP, internalclock and security configurations can be performed via the web-basedmanagement system. However, you can also load web pages you have createdyourself into the couplers/controllers, which have an internal file system,using FTP.
