Product overview, functions
2.4 Configuration limits and performance data
CP 1543-1
Operating Instructions, 12/2019, C79000-G8976-C289-08
17
Restrictions for UDP
●
Restrictions UDP broadcast / multicast
To avoid overloading the CP due to high broadcast / multicast frame traffic, the receipt of
UDP broadcast / multicast on the CP is limited.
●
UDP frame buffering
Length of the frame buffer: At least 7360 bytes
Following a buffer overflow, newly arriving frames that are not fetched by the user
program are discarded.
2.4.2
Characteristics of S7 communication
S7 communication provides data transfer via the ISO Transport or ISO-on-TCP protocols.
Characteristic
Explanation / values
Total number of freely usable S7 connections on
Industrial Ethernet
Max. 118
LAN interface - data field length generated by CP
per protocol data unit (PDU = protocol data unit)
•
For sending: 480 bytes / PDU
•
For receiving: 480 bytes / PDU
Number of reservable OP connections *
Max. 4
Number of reservable PG connections *
Max. 4
Number of HTTP connections for Web
Max. 4
* The CPU reserves connection resources. Take the specified values into account for programmed
connections also.
Note
Maximum values for an S7-1500 station
Depending on the CPU you are using, there are limit values for the S7-1500 station. Note the
information in the relevant documentation.