Performance data
2.4 Characteristic data of the SEND/RECEIVE Interface
CP 343-1 Lean
Manual, 10/2012, C79000−G8976−C198−07
17
Table 2- 3 Characteristic data of the SEND/RECEIVE Interface
Characteristic Explanation / values
Number of ISO-on-TCP connections + TCP
connections + UDP connections in total
8 maximum
Notes:
All UDP connections are also possible in
multicast mode.
Free UDP connections are supported by the
CP.
Maximum data length for the blocks AG_SEND
(as of V4.0) and AG_RECV (as of V4.0)
AG_SEND and AG_RECV allow the transfer of
blocks of data with the following length:
1 to 8192 bytes for ISO-on-TCP, TCP;
1 to 2048 bytes for UDP.
Restrictions for UDP
Transfer is not confirmed
The transmission of UDP frames is unconfirmed,
in other words the loss of messages is not
detected or displayed by the send block
(AG_SEND).
No receipt of UDP broadcast
To avoid communications overload of the CP due
to high broadcast load, the CP does not allow
receipt of UDP broadcasts.
UDP frame buffering
Size of the frame buffer with buffering enabled: 2
Kbytes
Note:
Following a buffer overflow, newly arriving frames
are discarded.
Execution times of the FCs AG_SEND / AG_RECV
The execution time required to process the FC blocks (AG_SEND, AG_RECV) required on
the S7-300 / C7-300 CPU is decisive for the calculation of the CPU cycle times (OB1) for
SEND/RECEIVE connections.
Note
Measurements of transmission and reaction times in Ethernet, PROFIBUS and PROFINET
networks for a series of configurations can be found on the Internet at the following address:
25209605 (http://support.automation.siemens.
com/WW/view/en/25209605)