Siemens SIMATIC S7 System Manual page 136

PLC device configuration
6.1 Configuring the operation of the PLC system
Ethernet port
If you want your CPU to obtain its Ethernet network port information from the project, click
the "IP address data is fixed to the values below and cannot be changed by other means"
checkbox. You can then enter the following Ethernet network information:
● IP address: Each device must have an Internet Protocol (IP) address. The device uses
this address to deliver data on a more complex, routed network.
● Subnet mask: A subnet is a logical grouping of connected network devices. Nodes on a
subnet are usually located in close physical proximity to each other on a Local Area
Network (LAN). The subnet mask defines the boundaries of an IP subnet. A subnet mask
of 255.255.255.0 is generally suitable for a local network.
● Default gateway: Gateways (or IP routers) are the link between LANs. Using a gateway, a
computer in a LAN can send messages to other networks, which might have other LANs
behind them. If the destination of the data is not within the LAN, the gateway forwards the
data to another network or group of networks where it can be delivered to its destination.
Gateways rely on IP addresses to deliver and receive data packets.
● Station name: The station name is the name by which this CPU is identified on the
network. Use a name that helps you identify the CPU on the Communications dialog.
Note
The station name follows the standard DNS (Domain Name System) naming conventions.
The S7-200 SMART CPUs limit the station name to a maximum of 63 characters, which
can consist of the lower case letters a through z, the digits 0 through 9, the hyphen
character (minus sign) and the period character.
The CPU prohibits certain names:
• The station name must not have the format n.n.n.n where n is a value of 0 through
• You cannot begin the station name with the string port-nnn or the string port-nnn-
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999.
nnnnn where n is a digit 0 through 9. For example, port-123 and port-123-45678 are
illegal station names. A station name cannot start or end with a hyphen or period.
System Manual, V2.3, 07/2017, A5E03822230-AF
S7-200 SMART