Siemens Simantic Net NCM for Industrial Ethernet S7 - Manual (Page 88)

Configuring Communication Connections
88
SIMATIC NET NCM S7 for Industrial Ethernet
C79000-G8976-C129–06
Amounts of Data
Refer to the manual /1/ supplied with the Ethernet CP for the number of
communication connections supported by the Ethernet CP. The number of
connections per station can be increased by adding more CPs.
The Ethernet CP can transfer the amounts of data shown in the table below per job
on one connection:
Table 4-1
ISO Transport ISO-on-TCP TCP UDP
Sending 8192 bytes 8192 bytes 8192 bytes 2048 bytes
Receiving 8192 bytes 8192 bytes 8192 bytes 2048 bytes
Notice
The transfer of more than 240 bytes of data is supported by newer version CPs.
Please note the information in Section 5 and in the manual of the Ethernet CP.
Tasks of the Ethernet CP
When handling the data transfer on a connection, the Ethernet CP has the
following tasks:
S
When receiving
Receiving data from Ethernet and transferring it to the user data area on the
CPU.
S When sending
Taking data from the user data area on the CPU and sending the data via
Ethernet.
For a free UDP connection, the following functions are also necessary in addition
to those above:
S
When receiving
Entry of the sender of the message in the job header.
S
When sending
Evaluation of the job header and addressing the partner
The connection is established automatically as soon as the partner is obtainable.