ETHERNET • 263
Network architecture
Modular I/O System
ETHERNET TCP/IP
5.1.1 Transmission
media
General ETHERNET transmission standards
For transmitting data the ETHERNET standard supports numerous technolo-
gies with various parameters of which differ from each other such as i.e.
transmission speed, medium, segment length and type of transmission.
10Base5
Uses a 10 mm 50 Ohm coaxial cable for a 10Mbps baseband signal for distances
of up to 500 m in a physical bus topology (often referred to as Thick
ETHERNET).
10Base2
Uses a 5 mm 50 Ohm coaxial cable for a 10Mbps baseband signal for distances
of up to 185 m in a physical bus topology (often referred to as Thin ETHERNET
or ThinNet).
10Base-T
Uses a 24 AWG UTP or STP/UTP (twisted pair cable) for a 10Mbps baseband
signal for distances up to 100 m in a physical star topology.
10Base-F
Uses a fiber-optic cable for a 10Mbps baseband signal for distances of up to
4 km in a physical star topology.
(There are three subspecifications: 10Base-FL for fiber-optic link, 10Base-FB for
fiber-optic backbone and 10Base-FP for fiber-optic passive).
Tab. 5-1: ETHERNET transmission standards
The four media types are shown with their IEEE shorthand identifiers. The
IEEE identifiers include three pieces of information. The first item, “10”,
stands for the media.
The third part of the identifier provides a rough indication of segment type or
length. For thick coaxial cable, the “5” indicates a 500 meter maximum length
allowed for individual thick coaxial segments. For thin coaxial cable, the “2”
is rounded up from the 185 meter maximum length for individual thin coaxial
segments. The “T” and “F” stand for ‘twisted pair’ and ‘fiber optic’, and sim-
ply indicate the cable type.
10Base-T
10Base-T Standard is used for the WAGO ETHERNET fieldbus coupler.
This allows for simple and economical network architecture using STP/UTP
cable as the transmission medium.
STP is shielded twisted pair category 5 cables (CAT 5). UTP is twisted pair
without shielding implemented.
Parameter
10BaseT
Medium
Twisted-Pair
Signaling technology
Baseband
Signaling code
Manchester encoding
Bit rate (Mbit / s)
10
Topology
Star
Max. segment length (m)
100
Max. packet size (Byte)
1512
Min. packet size (Byte)
64
Tab. 5-2: Important parameters of the 10Base-T ETHERNET standard
