Omron CS1W-ETN21 FINS/TCP Connection Status Word n+23, Communications, Procedure, Internal table

FINS/TCP Method															Section 6-3
	FINS/TCP Connection Status (Word n+23)
	While a connection with a remote node is established, the bit corresponding to
	the FINS/TCP connection status turns ON in the section of the CPU Bus Unit
	words allocated in the CIO Area. The bit turns OFF if the connection is termi-
	nated by a communications error or a FINS command (i.e., FINS/TCP CON-
	NECTION REMOTE NODE CHANGE REQUEST).
	15		14	13	12	11	10	09	08	07	06	05	04	03	02	01	00
	n+23
		*: Bit 15 corresponds to connection No. 16, bit 00 to connection No. 1, etc.
FINS/TCP	With FINS/TCP, FINS node addresses are exchanged immediately after a
Communications	connection is established. This makes it possible to determine the FINS node
Procedure	addresses to which the 16 connection numbers, and to manage them in an

internal table.

Personal computer

(Client)

Example:

IP address C

FINS node number A

Ethernet Unit

(Server)

Example:

IP address S

FINS node number B

Passive open

Active open	Connection request (C→	S)		Connection established
Connection established			Connection established
	FINS node number A sent
Local node No. sent			Remote node No. received
				FINS node numbers exchanged
Remote node No. received	FINS node number B sent		Local node No. sent
FINS frame sent			FINS frame sent
	Full duplex communications
				Normal data communications

After a connection has been established as a FINS/TCP server, it is termi- nated in the following ways.

•When the connection is closed by the client.

•When a FINS command to close the connection (FINS/TCP CONNEC- TION REMOTE NODE CHANGE REQUEST) is sent by the client.

•When there is no response from the client when the keep-alive function is in effect.

After a connection has been established as a FINS/TCP client, it can be termi- nated in the following ways.

•If the connection is closed by the server.

•If there is no response from the client when the keep-alive function is in effect.

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