Rockwell Automation 1747-AENTR SLC 500 EtherNet/IP Adapter User Manual - Manual (Page 20)

14 Rockwell Automation Publication 1747-UM076C-EN-E - January 2013
Chapter 3 Configure the Adapter for Your EtherNet/IP Network
IP Address
The IP address identifies each node on the IP network, or system of connected
networks. Each TCP/IP node on a network, including the adapter, must have a
unique IP address.
The IP address is 32 bits long and has a Network ID part and Host ID part.
Networks are classified A, B, C, or other. The class of the network determines
how an IP address is formatted.
You can distinguish the class of the IP address from the first integer in its dotted-
decimal IP address as follows:
Each node on the same physical network must have an IP address of the same
class and must have the same network ID. Each node on the same network must
have a different Host ID thus giving it a unique IP address.
IP addresses are written as four decimal integers (0…255) separated by periods
where each integer gives the value of one byte of the IP address.
Gateway Address
This section applies to multi-network systems. If you have a single network
system, refer to the next section.
The Gateway Address is the default address of a network. It provides a single
domain name and point of entry to the site. Gateways connect individual physical
networks into a system of networks.
Class A
Class B
Class C
Network ID
Host ID
Host ID
Host ID
0
0
0
10
0
110
7 8
15 16
31
31
31 23 24
Network ID
Network ID
Range of first
integer Class Range of first
integer Class
0 1…27 A 192…223 C
128…191 B 224… 255 Other
EXAMPLE For example, the 32-bit IP address:
10000000 00000001 00000000 00000001 is written as 128.1.0.1