Omron CS1W-ETN21 operation manual FINS/TCP Communications Method, Pairing in the FINS/TCP Method

IP Addresses in FINS Communications Section 5-2

FINS/TCP Communications Method

Pairing in the FINS/TCP Method

With the FINS/TCP method, communications are first established for each connection, and then remote FINS node addresses are mutually converted. (See note.) Then FINS message communications are executed. In this way, remote FINS node addresses and remote IP addresses are paired for each connection. Therefore, with the FINS/TCP method, there is no need to set IP address conversions (i.e., pairing FINS node addresses with IP addresses) as with FINS/UDP. All that is required is to use the CX-Programmer's Unit setup to set the remote IP address for each connection.

Note	The internal table is changed after connections are established.
Internal Processing	The Ethernet Unit executes the following processing when the FINS/TCP
	method is used.
	Local Device Is FINS/TCP Client

1,2,3... 1. Connections are established in TCP/IP protocol with the IP addresses set at the Unit (i.e., the IP address for each connection No.).

2.The remote node (i.e., the server) is notified of the FINS node address for the local device.

3.Notification is received from the remote node (i.e., the server) of the re- mote node's FINS node address.

4.The Ethernet Unit changes the internal table (FINS node address, IP ad- dress, and TCP port number).

5.FINS messages can then be sent and received.

Local Device Is a FINS/TCP Server

1,2,3... 1. A request to open a connection is received in TCP/IP protocol from the re- mote device (i.e., the client, either a personal computer or an Ethernet Unit), and the connection is established.

2.Notification is received from the remote node (i.e., the client) of the remote node's FINS node address.

3.The local device provides notification of the local FINS node address.

4.The Ethernet Unit changes the internal node correspondence table (FINS node address, IP address, and TCP port number).

5.FINS messages can then be sent and received.

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