
95
6
F
3
B
0
3
6
2
4.
UDP close request (using the SEND instruction)
a.
Function
Close the open UDP socket.
Release the (unlimited wait state) receive request and terminate the UDP socket.
b.
Transfer parameters
A
3100H
Module designation
A+1
CMD = 0034H
Command number
A+2
SportNO
Socket identifier (1 to 8)
c.
Status (See figure 4.3 for details on bits C, D, E and F.)
F
E
D
C
B
A
9
8
7
6
5
4
3
2
1
0
B
SportNO
TermSTS
B+1
Detailed information (Only valid when TermSTS = 0BH.)
d.
Important items
•
UDP close requests are processed with the highest priority and other executing requests are
discarded, even if the object socket is executing a UDP open, send, or receive request. Other
requests during the execution of this request will be discarded.
•
The next open request for the object socket can be executed as soon as the close request
completes normally.
•
An error is returned if a close request is issued for a socket that is not yet opened.
Status: Transmission error (TermSTS = 0BH)
Detailed information: Unopened (0081H)
•
An error is returned if a value other than 1 to 8 is specified as the socket identifier.
Status: Transmission error (TermSTS = 0BH)
Detailed information: Illegal socket identifier (0082H)
•
A UDP receive request will result in an error being returned if an unlimited wait state UDP
receive request is terminated with this request.
Status: Transmission completion timeout (TermSTS = 06H)
Supplement:
The T2N sees its requests (module control and socket interface transmission) to the Ethernet
Port as being "transmission" requests. As a result, when a request is forcibly terminated and a
response is not received from the Ethernet Port, the result is a send request timeout even if the
instruction was a RECV instruction.
•
If the T2N internal completion wait time limit (2 seconds) is exceeded for this request, the error
listed below is returned.
Status: Send completion timeout (TermSTS = 06H)
In this case, first verify that the Ethernet Port is not in the down state by checking the station
status, and then verify the open/closed state of the socket in the socket status.
SportNO: Socket identifier (1 to 8)
TermSTS: See tables 4.3 and 4.4.
Detail information: See table 4.5.