Omron SYSMAC CJ1W-EIP21 - Manual (Page 120)

94
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
IP
Ethernet
Node number
UDP port
number TCP port
number
TCP
IP address
Ethernet address
Must be allocated.
Automatically allocated
Application level
Transport level
Internet level
Physical level
FINS
UDP
IP
Ethernet
TCP
Node number
UDP port
number TCP port
number
IP address
Ethernet address
Receives communications data
conforming to Ethernet address,
IP address, UDP port number,
and FINS node number.
FINS header FINS data Ethernet V2 IP UDP