
Using Socket Services by Manipulating Dedicated Control Bits | Section |
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.
15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
m+9 to m+16 | - | - | - | - | - | - | - | - | - | - | - | - |
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TCP connection status
The status is shown in bits 0 to 3
Number | Status | Meaning |
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00000000 | CLOSED | Connection closed. |
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00000001 | LISTEN | Waiting for connection. |
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00000002 | SYN SENT | SYN sent in active status. |
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00000003 | SYN RECEIVED | SYN received and sent. |
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00000004 | ESTABLISHED | Already established. |
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00000005 | CLOSE WAIT | FIN received and waiting for completion. |
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00000006 | FIN WAIT1 | Completed and FIN sent. |
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00000007 | CLOSING | Completed and exchanged FIN. Awaiting ACK. |
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00000008 | LAST ACK | FIN sent and completed. Awaiting ACK. |
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00000009 | FIN WAIT2 | Completed and ACK received. Awaiting FIN. |
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0000000A | TIME WAIT | After closing, pauses twice the maximum seg- |
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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.
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