Assigning Internet Protocol (Ip) Addresses; Assigning Ip Addresses To Programming And Network Devices - Siemens SIMATIC S7 System Manual

Communication
8.4 Ethernet
8.4.4

Assigning Internet Protocol (IP) addresses

8.4.4.1

Assigning IP addresses to programming and network devices

If your programming device is using a network adapter card connected to your plant LAN
(and possibly the World Wide Web), both the programming device and the CPU must exist
on the same subnet. The subnet is specified as a combination of the IP Address and subnet
mask for the device. Please see your local network administrator for help.
The Network ID is the first part of the IP address (first three octets) (for example,
211.154.184.16) that determines what IP network you are on. The subnet mask normally has
a value of 255.255.255.0; however, since your computer is on a plant LAN, the subnet mask
may have various values (for example, 255.255.254.0) in order to set up unique subnets.
The subnet mask, when combined with the device IP address in a logical AND operation,
defines the boundaries of an IP subnet.
Note
In a World Wide Web scenario, where your programming devices, network devices, and IP
routers will communicate with the world, unique IP addresses must be assigned to avoid
conflict with other network users. Contact your company IT department personnel, who are
familiar with your plant networks, for assignment of your IP addresses.
Note
A secondary network adapter card is useful when you do not want your CPU on your
company LAN. During initial testing or commissioning tests, this arrangement is particularly
useful.
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System Manual, V2.3, 07/2017, A5E03822230-AF
S7-200 SMART