Omron CS CJ1W-ETN21 - Manual (Page 206)

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FINS/TCP Method Section 7-4
Connection Sequence for
Automatic Allocation of
FINS Node Addresses
1,2,3... 1. The client specifies the client node address as 00000000 hexadecimal in
the server as the automatically allocated FINS node address, and sends it
using the FINS NODE ADDRESS DATA SEND (CLIENT TO SERVER)
command.
2. The server checks the client node address in the received command to see
whether an automatically allocated FINS node address is specified, and
the client node address is determined from the automatically allocated
FINS node addresses controlled by the server.
3. The server stores its own node address in the server node address field
and the automatically allocated client FINS node address in the client node
address field, and sends to the client using the FINS NODE ADDRESS
DATA SEND (SERVER TO CLIENT) command.
4. The server node address is obtained from the server node address field in
the received command, and the client node address is obtained from the
client node address field.
5. A FINS message is sent using the FINS FRAME SEND command.
6. The FINS message is separated out from the received command.
Note In steps 5 and 6, both the client and server can send and receive FINS mes-
sages (commands/responses) in both directions.
connect
send
recv
accept
recv
send
SYN
SYN, ACK
ACK
ACK
ACK
connect
recv
send
send
recv
ACK
ACK
Client Server
Socket interface
Message from TCP/IP layer
Message from host layer
Normal
A
B
C
D
E
F
F
E