Rockwell Automation 1756-ENET/B ControlLogix Ethernet Communication Interface Module User Manual - Manual (Page 35)

Publication 1756-UM051B-EN-P - November 2000
Before You Configure Your Module 3-3
Configuration
Requirements Before you can use your Ethernet module, you must configure its IP
address, gateway address, and subnet mask. The module ships with
the Rockwell BootP utility, which you can use to perform the
configuration. You can also use RSLinx software, generic BootP
software, or, within some limitations, a DHCP server. These methods
are described in chapter 4.
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
Ethernet module) must have a unique IP address.
The IP address is 32 bits long and has a net ID part and a host ID part.
Each network is a Class A, Class B, or Class C network. The class of a
network determines how an IP address is formatted.
Each node on the same physical network must have an IP address of
the same class and must have the same net 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.
For example, the 32-bit IP address:
10000010 00000000 00000000 00000001 is written as 130.0.0.1.
You can distinguish the class of an IP address from the first integer in
its dotted-decimal IP address as follows:
Class A
Class B
Class C
net ID
net ID
net ID host ID
host ID
host ID 0
0 1
0 1
0 1
0
0
1
1 1
8
8
8
16
16
16 24
24
24
31
31
31
Range of first integer Class Range of first integer Class
0 -127 A 192 - 223 C
128 -191 B 224 - 255 other
EXAMPLE