Omron CS1W-ETN21 User Manual

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IP Addresses in FINS Communications

Section 5-2

• Connection method:

FINS/UDP

• FINS Node Address Not Registered to IP Address Table

The following address is registered to the internal table.

• Remote IP address:

Local IP address network number + FINS
node address

• Remote UDP port number: UDP port number set for local Unit

• Connection method:

FINS/UDP

With the combined method, records of FINS nodes registered to the IP
address table are not dynamically changed. For all others nodes, the data
from FINS nodes registered with a remote IP address of 0.0.0.0 can be
dynamically changed when the Unit is turned ON or restarted, according to
FINS messages received from remote nodes. This can be used effectively
when the remote node is a device such as a personal computer and IP
addresses are dynamically changed by a method such as DHCP.

Example

Note

When an internal table IP address has been changed with the reception of a
FINS command, this is sent to the IP address in the internal table.

Prohibiting Dynamically Changing Remote IP Addresses

For Ethernet Units with Unit Ver. 1.3 or later, methods used to dynamically
change remote IP addresses (automatic generation, IP address table, or com-
bined (mixed) method) can be prohibited (protected against). Use the CX-Pro-
grammer unit setting function (version 5.0 and higher) or Web function setting
window to make this setting.

When dynamically changing remote (destination) IP addresses is prohibited,
the internal table for each method is maintained in the state when the power
was turned ON or restarted. Therefore, protection can be provided against
access using FINS/UDP from personal computers or other devices that have
dynamically changing IP addresses. To prohibit (protect from) dynamic
changes, deselect the Change Dynamically option in the Setup Tab of the Unit
Setup.

When FINS Command is Sent

FINS node number

Node number in
IP address table

153.214.0.62

153.214.0.129

153.218.51.8

153.218.51.10

Node number not
in IP address table

Automatic
generation
method

IP address table

FINS node
number

Network number: xx.xx.00.00

IP address

FINS node number: xx

IP address
FINS command
sent

IP address
(See note.)
FINS command
sent

When FINS Command is Received

Node number
not in IP
address table

Changed

Internal table

IP address
153.218.51.10
FINS response
returned

Automatic
generation
method
(dynamic)

IP address
method