6-2
Section
Using Socket Services with Socket Service Request Switches
106
DM Area: (100 x unit number) +9 to +16. Refer to TCP Socket Con-
nection Status on page 58 and to Appendix D TCP Status Transitions for details.
6-2-5 Application Procedure
Procedure
1, 2, 3...
1. Set the socket service parameters in the CPU Bus Unit Area in the DM Area.
Remote UDP/TCP port No.
Number of bytes to send/receive
Send/Receive data address
Parameters
m = (100 x unit number)
CPU Bus Unit Area in the DM Area
Socket Service Parameter Area 1
Socket Service Parameter Area 8
Socket Service Parameter Area 2
Time out time
Response code
UDP/TCP socket No.
Local UDP/TCP port No.
Remote IP address
15
0
m+18
m+28
m+88
2. Turn ON the Socket Service Request Bits in the CPU Bus Unit Area in the
CIO Area.
Socket Service
Request Switches 7
Socket Service
Request Switches 1
Socket Service
Request Switches 8
Socket Service
Request Switches 2
CPU Bus Unit Area in the CIO Area
Close Request
Switch
Receive Request Switch
Send Request Switch
UDP Open Request Switch
TCP Passive Open Request Switch
TCP Active Open Request Switch
3. When a send or receive request is made, the data will be automatically sent
or received according to the send/receive data address in the Socket Ser-
vice Parameter Area. When processing has been completed, a response
code will be automatically stored in the Socket Service Parameters.
Number of bytes to send/receive
Send/receive data address
I/O memory
Send
or
Receive
Response code
Stored
Precautions
A Socket Service Parameter Area cannot be used for other sockets once open
processing has been successfully completed for it. Check the socket status be-
fore attempting to open a socket. TCP socket status is provided in words m+9 to
m+16 in the DM Area for sockets 1 to 8.
TCP Connection Status
The TCP connection status is provided for ports for which TCP sockets have
been opened. When a port is closed, the previous status will remain in the DM
