Connections - Siemens SIMATIC NET S7-300 Manual

5.3

Connections

Characteristics of a Connection
A communication connection allows program-controlled communication between
two nodes on Industrial Ethernet with the following characteristics:
S The data transfer is bi-directional, in other words, it is possible to transmit and
receive on the connection simultaneously.
S Both stations have the same rights, in other words, each station can trigger the
send and receive procedures in response to events.
S The address of the communication partner is specified in the configuration.
Exceptions to this are:
- free UDP connections
Here, the address is specified at the FC interface in the user program.
- programmed communication connections (see Chapter 6)
SIMATIC S7 station
with Ethernet CP
Figure 5-2 Sending and Receiving via one Communication Connection
S7-CPs for Industrial Ethernet Configuring and Commissioning
Release 01/2007
C79000-G8976-C182-07
Ethernet CP
send
receive
send
receive
5 Configuring Communication Connections
Ethernet
node
Communication
connection
Ethernet
node
Communication
connection
receive
send
receive
send
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