6-2
Section
Using Socket Services with Socket Service Request Switches
104
Bit
Switch
Status
Manipulated
by
Unit operation
8
0
UDP Open
ON
User
UDP socket opened when switch is turned ON.
Request Switch
OFF
Unit
Unit turns OFF switch when open processing has been
completed (i.e., when a connection has been made).
9
1
TCP Passive Open
ON
User
Passive TCP socket opened when switch is turned ON.
Request Switch
OFF
Unit
Unit turns OFF switch when open processing has been
completed (i.e., when a connection has been made).
10
2
TCP Active Open
ON
User
Active TCP socket opened when switch is turned ON.
Request Switch
OFF
Unit
Unit turns OFF switch when open processing has been
completed (i.e., when a connection has been made)
11
3
Send Request
Switch
ON
User
Send processing executed when switch is turned ON.
(The protocol (TCP/UDP) is determined when the socket is
opened.)
OFF
Unit
Unit turns OFF switch when send processing has been
completed.
12
4
Receive Request
Switch
ON
User
Receive processing executed when switch is turned ON.
(The protocol (TCP/UDP) is determined when the socket is
opened.)
OFF
Unit
Unit turns OFF switch when receive processing has been
completed.
13
5
Close Request
Switch
ON
User
Close processing executed when switch is turned ON.
(The protocol (TCP/UDP) is determined when the socket is
opened.)
OFF
Unit
Unit turns OFF switch when close processing has been
completed.
As shown in the above table, the Request Switches are turned OFF by the Ether-
net Unit when the requested processes has been completed. The ladder dia-
gram should be programmed to check the response code when the relevant
Socket Service Request Switch turns OFF.
Note There is also a Socket Force-close Switch in bit 2 of the first word allocated to the
Ethernet Unit in the CPU Bus Unit Area in the CIO Area. When the Socket Force-
close Switch is turned ON, all sockets that are open will be force-closed. Refer to
page 51 for details.
