Omron CS CJ1W-ETN21 - Manual (Page 136)

112
Using Socket Services by Manipulating Dedicated Control Bits Section 6-7
Up to 4,096 bytes of data are stored in the reception buffer, but the value
stored is within the range (maximum: 1,984 bytes) that can be set by manipu-
lating the control bits or sending the receive request in the CMND(490)
instruction.
0000 hexadecimal: 0 bytes
07C0 hexadecimal: 1,984 bytes
■ TCP Connection Status (Ethernet Unit to CPU Unit)
The TCP Connection Status shows the status of a port that has been opened
using the TCP socket. This port status is stored even after the port is closed,
and remains until the socket is used to open the port again.
The TCP Connection Status Bits are not synchronized with the Socket Status
words, however, so the status conversion timing is slightly different.
The status is shown in bits 0 to 3 (1-digit hexadecimal), as follows:
6-7 Using Socket Services by Manipulating Dedicated Control
Bits
6-7-1 Application Procedure
Procedure
1,2,3... 1. Set the socket service parameters in the CPU Bus Unit Area in the DM Ar-
ea.
15 14 13 12 10 9 8 7 6 5 4 3 2 1 0 11
m+9 to m+16
TCP connection status
- - - - - - - - - - - -
Number Status Meaning
00000000 CLOSED Connection closed.
00000001 LISTEN Waiting for connection.
00000002 SYN SENT SYN sent in active status.
00000003 SYN RECEIVED SYN received and sent.
00000004 ESTABLISHED Already established.
00000005 CLOSE WAIT FIN received and waiting for completion.
00000006 FIN WAIT1 Completed and FIN sent.
00000007 CLOSING Completed and exchanged FIN. Awaiting ACK.
00000008 LAST ACK FIN sent and completed. Awaiting ACK.
00000009 FIN WAIT2 Completed and ACK received. Awaiting FIN.
0000000A TIME WAIT After closing, pauses twice the maximum seg-
ment life (2MSL).