Omron CS CJ1W-ETN21 Operation Manual page 205

FINS/TCP Method
1,2,3...
Note
Error Connection
Sequence
1,2,3...
1. After the TCP connection is established, the client node address is sent by
the client to the server using the FINS NODE ADDRESS DATA SEND (CLI-
ENT TO SERVER) command.
2. The client's FINS node address (client node address) is obtained from the
received command.
3. The server's node address is sent by the server to the client using the FINS
NODE ADDRESS DATA SEND (SERVER TO CLIENT) command.
4. The server's FINS node address is obtained from the received command.
5. The FINS message is sent using the FINS FRAME SEND command.
6. The FINS message is separated out from the received command.
In steps 5 and 6 both the client and server can send and receive FINS mes-
sages (commands/responses) in both directions.
Client
SYN
connect
SYN, ACK
ACK
A
send
ACK
D
recv
ACK
FIN
ACK
close
FIN
Connection closed
according to TCP/IP
protocol procedure.
1. The client sends the FINS NODE ADDRESS DATA SEND (CLIENT TO
SERVER) command to the server.
2. The received command is decoded (e.g., if an error occurs, the code that
is not 'FINS' (ASCII code) in the command header is stored.)
3. The server sends the error code for the detected error (in this example,
00000001 hexadecimal: Header is not 'FINS' (ASCII code)) in the FINS
NODE ADDRESS DATA SEND (SERVER TO CLIENT) command to the
client, and the TCP/IP port is closed.
4. The error code for the received command is decoded, and the TCP/IP port
is closed.
Server
accept
recv
B
Error
C
send
close
Socket interface
connect
Message from TCP/IP layer
Message from host layer
Section 7-4
181