8
Deployment Ethernet communication - productive
8.1 Basics - Industrial Ethernet in automation
The flow of information in a company presents a vast spectrum of requirements that must
be met by the communication systems. Depending on the area of business the bus
system or LAN must support a different number of users, different volumes of data must
be transferred and the intervals between transfers may vary, etc. It is for this reason that
different bus systems are employed depending on the respective task. These may be
subdivided into different classes. The following model depicts the relationship between
the different bus systems and the hierarchical structures of a company:
Industrial Ethernet is an electrical net based on shielded twisted pair cabling or optical net
based on optical fibre. Industrial Ethernet is defined by the international standard IEEE
802.3
The net access of Industrial Ethernet corresponds to IEEE 802.3 - CSMA/CD (
C
arrier
S
ense
M
ultiple
A
ccess/
C
ollision
D
etection) scheme:
n
Every station "listens” on the bus cable and receives communication messages that
are addressed to it.
n
Stations will only initiate a transmission when the line is unoccupied.
n
In the event that two participants should start transmitting simultaneously, they will
detect this and stop transmitting to restart after a random delay time has expired.
n
Using switches there is the possibility for communication without collisions.
Overview
Industrial Ethernet
System 300S
+
Deployment Ethernet communication - productive
Basics - Industrial Ethernet in automation
HB140 | CPU | 315-4PN23 | en | 18-02
100
