Siemens S7-300 - Page 93

Configuring communications connections
5.1 Procedure and connection properties
Configuring and commissioning S7 CPs for Industrial Ethernet
Configuration Manual, 09/2013, C79000-G8976-C182-13
93
Note
The term
"connection" is also used here for UDP. The reason: During configuration
(just as in TCP), the communication partners are assigned to each other and therefore
logically "connected". In actual fact, with UDP there is no explicit connection
establishment be
tween communication partners.
Tasks of the Ethernet CP
When handling the data transfer on a connection, the Ethernet CP has the following tasks:
● When receiving
Receiving data from Ethernet and transferring it to the user data area on the CPU.
● When sending
Taking data from the user data area on the CPU and sending the data via Ethernet.
The connection is established automatically as soon as the partner is obtainable.
For a free UDP connection, the following functions are also necessary in addition to those
above:
● When receiving
Entry of the sender of the message in the job header.
● When sending
Evaluation of the job header and addressing the partner.