Omron SYSMAC CJ1W-EIP21, Operation Manuals

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4 Determining IP Addresses
4-2
CJ-series EtherNet/IP Units Operation Manual for NJ-series CPU Unit (W495)
4-1 IP Addresses
IP addresses are made up of 32 bits of binary data that specify the network number (net ID) and host
number (host ID). The network number identifies the network, and the host number identifies the node
(or host) on the network. IP addresses are divided into three classes, A, B, and C, so that the address
system can be selected according to the scale of the network. (Classes D and E are not used.)
The number of networks in each class and the number of hosts possible on the network differ according
to the class.
The 32 bits of binary data in an IP address are divided into four sections of eight bits each. IP
addresses are represented by the decimal equivalent of each of the four octets in the 32-bit address,
each separated by a period.
For example, the binary address 10000010 00111010 00010001 00100000 would be represented as
130.58.17.32.
4-1-1 IP Address Configuration
Class Number of networks Number of hosts
Class A Small
2
24
−
2 max. (16,777,214 max.)
Class B Medium
2
16 −
2 max. (65,534 max.)
Class C Large
2
8 −
2 max. (254 max.)
(Cannot be used.)
(Cannot be used.)
Experimental address
Multicast address
Host ID (8 bits)
Network ID (21 bits)
Host ID (16 bits) Network ID (14 bits)
Host ID (24 bits) Network ID (7 bits)
Class E
Bit 31
Class D
Bit 31
Class C
Bit 31
Class B
Bit 31
Class A
Bit 31
0
23 0
1
15 0
1
7 0
0
1 0
1
0
1 1
1
0
1 1
0
1