Technical data

Fieldbus Communication • 163
ETHERNET
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
4 Fieldbus Communication
4.1 ETHERNET
4.1.1 General
ETHERNET is a technology, which has been proven and established as an ef-
fective means of data transmission in the field of information technology and
office communication. Within a short time ETHERNET has also made a suc-
cessful 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.). Stan-
dardization (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 Pro-
tocol / Internet Protocol) to allow communication between different systems.
The TCP/IP protocol stack offers a high degree of reliability for the transmis-
sion of information.
In the ETHERNET based (programmable) fieldbus couplers and controllers
developed by WAGO, usually various application protocols have been imple-
mented 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 in-
terface.
In addition to a series of management and diagnostic protocols, fieldbus spe-
cific application protocols are implemented for control of the module data, de-
pending upon the coupler or controller, e. g. MODBUS TCP (UDP),
EtherNet/IP, BACnet/IP, KNXNET/IP, PROFINET, Powerlink, SERCOS III
or others.
Information such as the fieldbus node architecture, network statistics and di-
agnostic 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 appli-
cation, 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.