Siemens S7-1500 Operating Instructions Manual page 17

The following characteristics are important (OUC + FETCH/WRITE):
Characteristic
Number of connections
Maximum data length for program blocks
LAN interface max. data field length generat-
ed by CP per protocol data unit(TPDU =
transport protocol data unit)
Note
Connection resources of the CPU
Depending on the CPU type, different numbers of connection resources are available. The
number of connection resources is the decisive factor for the number of configurable
connections. This means that the values that can actually be achieved may be lower than
specified in this section describing the CP.
You will find detailed information on the topic of connection resources in the
"Communication" function manual, refer to the section Guide to the documentation (Page 9).
CP 1543-1
Operating Instructions, 05/2017, C79000-G8976-C289-07
2.5 Configuration limits and performance data
Explanation / values
Number of configured and programmed +connections in total (ISO
•
transport + ISO-on-TCP + TCP + UDP + FETCH/WRITE + e-mail):
Max. 118
Of which maximum:
– TCP connections: 1...118
– ISO-on-TCP connections: 1...118
– ISO transport connections: 1...118
– Total number of UDP connections (specified and free) that can be
configured: 1...118
– Connection for e-mail: 1
– Connections for FETCH/WRITE: 1...16
Notes:
Avoid receive overload
1)
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).
Program blocks allow the transfer of user data in the following lengths:
ISO-on-TCP, TCP, ISO transport: 1 to 64 kB
•
UDP: 1 to 1452 bytes
•
E-mail
•
– Job header + user data: 1 to 256 bytes
– E-mail attachment: up to 64 kbytes
sending
•
ISO transport, ISOonTCP, TCP: 1452 bytes / TPDU
receiving
•
– ISO transport: 512 bytes / TPDU
– ISO-on-TCP: 1452 bytes / TPDU
– TCP: 1452 bytes / TPDU
Product overview, functions
1)
17