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Fieldbus Communication
ETHERNET
WAGO-I/O-SYSTEM
750
PROFINET IO
4 Fieldbus Communication
4.1 ETHERNET
4.1.1 General
ETHERNET is a technology, which has been proven and established as an
effective means of data transmission in the field of information technology
and office communication. Within a short time ETHERNET has also made a
successful breakthrough in the area of private PC networks throughout the
world.
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 a
transmission medium. Connection to ETHERNET, often already existing in
networks, (LAN, Internet) is easy and the data exchange at a transmission rate
of 10 Mbps or for some couplers/controllers also 100 Mbps is very fast.
ETHERNET has been equipped with higher level communication software in
addition to standard IEEE 802.3, such as TCP/IP (Transmission Control
Protocol / Internet Protocol) to allow communication between different
systems. The TCP/IP protocol stack offers a high degree of reliability for the
transmission of information.
In the ETHERNET based (programmable) fieldbus couplers and controllers
developed by WAGO, usually various application protocols have been
implemented 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 ETHERNET
interface.
In addition to a series of management and diagnostic protocols, fieldbus
specific 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 or
others.
Information such as the fieldbus node architecture, network statistics and
diagnostic information is stored in the ETHERNET (programmable) fieldbus
couplers and controllers and can be viewed as HTML pages via a web browser
(e.g., Microsoft Internet-Explorer, Netscape Navigator) being served from the
HTTP server in the couplers and controllers.
Furthermore, depending on the requirements of the respective industrial
application, various settings such as selection of protocols, TCP/IP, internal
clock and security configurations can be performed via the web-based
management system. However, you can also load web pages you have created
yourself into the couplers/controllers, which have an internal file system,
using FTP.
