WAGO -I/O-SYSTEM 750 Technical Description, Installation And Configuration page 125

Deterministic ETHERNET
The TCP/IP software or the user program in each subscriber can limit
transmittable messages to make it possible to determine real-time
requirements. At the same time the maximum medium message rate
(datagrams per second), the maximum medium duration of a message, and
the minimum time interval between the messages (waiting time of the
subscriber) is limited.
Therefore, the delay time of a message is predictable.
Switched ETHERNET
In the case of Switched Ethernet, several fieldbus nodes are connected by a
switch. When data from a network segment reaches the switch, it saves the
data and checks for the segment and the node to which this data is to be sent.
The message is then only sent to the node with the correct target address.
This reduces the data traffic over the network, extends the bandwidth and
prevents collisions. The runtimes can be defined and calculated, making the
Switched Ethernet deterministic.
Fig. 4-7: Principle of Switched ETHERNET
WAGO-I/O-SYSTEM 750
PROFINET IO
Fieldbus Communication
ETHERNET
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