Rockwell Automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User Manual - Manual (Page 102)

Chapter 6
Using the Ethernet Interface
6-21
The following flow chart shows a client/server interface.
socket()Ċcreatesa
communication socket
bind()Ċtiesa name/address
structure to socket
listen()Ċestablishes socket as
a server, sets number simultaneous
connectionsallowed
accept()Ċwaits for client to establish
connection, createsnew socket for
client use, old socket waits for next
connect ( )
recv() or send()Ċtransfer of data
and perform server stuff"
shutdown()Ċdisallows
further transfers
Server Program
socket()Ċcreatesa
communication socket
get host by nameĊlooksup
server's IP address in hosts"
given hostname
get serv by nameĊlooksup
wellĆknown servce number"
in services" given name
connect()Ċestablishes connection
to server (which must already be
waiting with accept ( ))
send() or recv() or do client
stuff" until done with service
close()Ċterminate existence of
socket data path
Client Program
exit()Ċdone!
close()Ċterminate existence
of socket acquired from
accept()
data transfer and
agree when done
establish connection
exit if we did fork() above
wait
for
next
client
(see note)
Note: fork() for multiĆconnect service
Refer to the OS-9 Internet Software Reference Manual, publication
1771-6.4.11, Appendix B, for example programs. Each of the three
different examples provide client and server programs using TCP sockets.