Siemens SIMATIC S7 System Manual page 500

Libraries
9.4 Open user communication library
●
remote device. IPaddr1 is the most significant byte of the IP address, and IPaddr4 is the
least significant byte of the IP address. For example: For the IP address 192.168.2.15,
set these values:
– IPaddr1 = 192
– IPaddr2 = 168
– IPaddr3 = 2
– IPaddr4 = 15
The IP address cannot be any of the following values:
– 0.0.0.0 (for an active connection)
– Any broadcast IP address (for example, 255.255.255.255)
– Any multicast address
– The IP address of the local CPU
You can use the IP address of 0.0.0.0 for a passive connection. By selecting the IP
address of 0.0.0.0, the S7-200 SMART CPU accepts a connection from any remote IP
address. Selecting a non-zero IP address for a passive connection causes the CPU to
only accept a connection from the specified address.
● RemPort: The RemPort is the port number on the remote device. You use port numbers
for TCP and UDP protocols to route the message within the device.
The rules for remote port numbers are as follows:
– The valid port number range is 1 to 49151.
– The suggested range for port numbers is 2000 to 5000.
– The CPU ignores the remote port number for passive connections (You can set it to
● LocPort: The LocPort parameter is the port number on the local CPU. You use port
numbers for TCP and UDP protocols to route the message within the device. The local
port number must be unique for all passive connections.
The rules for local port numbers are as follows:
– The valid port number range is 1 to 49151.
– You cannot use port numbers 20, 21, 25, 80, 102, 135, 161, 162, 443, and 34962 to
– The suggested range for port numbers is 2000 to 5000.
– The local port numbers must be unique for passive connections (no duplicates).
500
IPaddr1, IPaddr2, IPaddr3 and IPaddr4: These are the four IP address octets of the
zero).
34964. These ports have specific assignments.
System Manual, V2.3, 07/2017, A5E03822230-AF
S7-200 SMART