Omron CJ1W-EIP21 用户手册

IP Addresses in FINS Communications

Section 5-2

5-1-5

CIDR

CIDR, or classless interdomain routing, is used to assign IP addresses that do
not use classes. IP addresses that use classes are separated into blocks
according to net IDs and host IDs, resulting in inefficient usage of IP address
space.

CIDR does not use classes, so IP address space can be divided as required
to more efficiently use IP address space. For example, using a subnet mask
setting with CIDR enables building a horizontally distributed network exceed-
ing 254 nodes even if a class C address block (e.g., 192, 168...).

CIDR was added for unit version 2.0.

5-2

IP Addresses in FINS Communications

5-2-1

Specifying Nodes in FINS Communications Services

With FINS communications services on an Ethernet network, IP addresses,
UDP port numbers, and TCP port numbers are paired with FINS node
addresses to specify nodes on the network.

Note

Use the Node Address Setting Switches (NODE NO.) on the front of the Eth-
erNet/IP Unit or, for the built-in EtherNet/IP port, on the front of the CPU Unit
to set the FINS node address.

Allocating Addresses to EtherNet/IP Units and Built-in EtherNet/IP Ports

FINS Message Reception
for EtherNet/IP Units or
Built-in EtherNet/IP Ports

The IP address, FINS/UDP port number, and FINS/TCP port number set for
the EtherNet/IP Unit or built-in EtherNet/IP port are mainly used when receiv-
ing FINS communications messages.

Subnet mask range

192.0.0.0 to 255.255.255.252

Application level

Transport level

Internet level

Physical level

FINS

UDP

Ethernet

Node number

UDP port
number

TCP port
number

TCP

IP address

Ethernet address

Must be allocated.

Automatically allocated