Siemens SIMATIC NET S7-400 - SENDRECEIVE Interface Performance

Performance data
2.3 SEND/RECEIVE interface
CP 443-1 (EX30)
Manual, 03/2019, C79000-G8976-C255-05
21
2.3
SEND/RECEIVE interface
2.3.1
Characteristic data
The SEND/RECEIVE interface provides access to communication using TCP, ISOonTCP,
ISO transport, email, and UDP connections. The following characteristics are important:
Characteristic
Explanation / values
Number of SEND/RECEIVE connections
• TCP connections: 1...64
1)
• ISO-on-TCP connections: 1...64
• ISO transport connections: 1...64
• Total number of UDP connections (specified and free) that can be
configured: 1 to 64 (of those up to 48 in multicast mode)
• Max. number of connections in total: Max. 64
(ISO transport + ISO-on-TCP + TCP + UDP)
Refer to the example in the section General characteristic data (Page 19).
1)
Note on TCP connections: Avoiding receive overload
The flow control on TCP connections cannot control permanent overload
of the recipient. You should therefore make sure that the processing ca-
pabilities of a receiving CP are not permanently exceeded by the sender
(approximately 150200 messages per second).
Number of SEND/RECV connections in
SPEED SEND/RECV mode
The number depends on the CPU type being used.
• Per CPU 412/414 maximum 30
• Per CPU 416/417 maximum 62
Maximum data length for AG_SEND and
AG_RECV program blocks
AG_SEND and AG_RECV were shipped with predecessors of the CP and
allow the transfer of user data with a length from 1 to 240 bytes. The
version of the CP described here continues to support these blocks.
Maximum data length for AG_LSEND and
AG_LRECV program blocks
AG_LSEND and AG_LRECV allow the transfer of user data with the fol-
lowing lengths:
• ISO-on-TCP, TCP, ISO transport: 1 to 8192 bytes
• UDP: 1 to 2048 bytes
• E-mail (job header + user data): 1 to 8192 bytes