Siemens SIMATIC S7-1500 Function Manual page 25

Communications services
3.2 Communications protocols and port numbers used for Ethernet communication
Protocol Port num-
ber
Modbus 502
TCP
Modbus
Transmission
Control Proto-
col
OPC UA 4840
Open Platform
Communica-
tions
Unified Archi-
tecture
1 ... 1999
OUC
1
Open User can be used
Communica- to limited
tion extent
2
and
2000 ...
5000
Secure OUC
Recom-
mended
5001 ...
49151
can be used
to limited
extent
2
IGMPv2 Not relevant (3) Network layer
Internet Group
Management
Protocol
Reserved 49152 ...
65535
Note: The open communication provides direct access to the UDP/TCP for the user. The user is responsible for observ-
1
ing the port restrictions/definitions of the IANA (Internet Assigned Numbers Authority).
Do not use ports for OUC, which are already used by other protocols
2
24
(2) Link layer Function
(4) Transport layer
(4) TCP Modbus/TCP protocol
(4) TCP Based on the TCP/IP proto-
col
(4) TCP Open User Communication
(4) UDP (TCP/UDP)
Secure Open User Com-
munication (TLS)
Internet Group Management
Protocol
(4) TCP -
(4) UDP
Description
Modbus/TCP is used by
MB_CLIENT/MB_SERVER instructions
in the user program.
Communication standard ranging from
the enterprise level to the field level.
OUC instructions provide connection
establishment, connection termination
and data transfer based on the socket
layer.
Network protocol for the organization of
multicast groups.
Dynamic port area used for active con-
nection end point if the application does
not determine the local port number.
.
Function Manual, 11/2019, A5E03735815-AH
Communication