Siemens S7-300 - Page 106

Configuring communications connections
5.7 Configuring UDP connection properties
Configuring and commissioning S7 CPs for Industrial Ethernet
106 Configuration Manual, 09/2013, C79000-G8976-C182-13
Ports
The ports or port addresses define the access point to the user program within the station /
CPU. They must be unique within the station / CPU!
The following table shows the range of values:
Application / note
Port addresses
Fixed; must not be modified!
0
Default assignment; should not be used (well-known ports)
1..1024
Range used by STEP 7 in which a free port address is searched
for and assigned.
2000 or higher
The following local port numbers are reserved. Do not use this in the connection
configuration.
Table 5- 5 Reserved port numbers
Port number
Protocol
Service
161
UDP
SNMP_REQUEST
500 UDP ISAKMP (Internet Security Association and Key
Management Protocol)
3820
UDP
SCP (Security Configuration Protocol)
4500
UDP
IPSec NAT Traversal
34964
UDP
PN IO
65532
UDP
NTP
65533
UDP
NTP
65534
UDP
NTP
65535
UDP
NTP
Unspecified UDP connection
An unspecified UDP connection can be used in two ways:
● Free UDP connection
To configure a free UDP connection, select the "Address assignment in block" check box.
The input boxes for the remote IP address and the remote port are then deactivated since
the destination addresses are now specified by the user program.
● Connection to a "remote station" in a different project
You can specify the remote IP address and the port for any destination station. The
destination station can be in the current STEP 7 project or in another project.
Note the following:
Since there is no connection establishment with UDP (datagram service), communication
via the configured UDP connection is only possible if the partner addresses (IP address
and port) are specified.