Hitachi Hidic EH-150 Applications Manual page 54

Preliminary Rev.03
7.2.2 Close connection
The procedure for closing connection is shown as fig.7.2.2.1.
Host PC
(A-2)
(A-3)
(A). In case EH-ETH requests to close connection
(A-1) EH-ETH requests to close connection to the host PC.
Host PC receives the request to close from EH-ETH, and
(A-2)
replies back ACK.
When the host PC does not have data to send, it replies back
(A-3)
FIN ACK.
EH-ETH receives the FIN ACK and replies back ACK after
(A-3)
waiting a time designated in TIME_WAIT value.
(B-1) Host PC requests to close connection to the EH-ETH.
EH-ETH receives the request to close from Host PC, and
(B-2)
replies back ACK
When the EH-ETH does not have data to send, it replies
(B-3)
back FIN ACK.
(B-3) The host PC receives the FIN ACK and replied back ACK.
*1: This is only in case "Close mode control" is disabled. The "Close mode control" is mentioned in the
followings.
The conditions to close connection are ;
(1). EH-ETH receives a request to close from user program during connection opened.
(2). EH-ETH receives a request to close from other stations during connection opened.
Description in this manual might be modified without notice.
EH-ETH
(A-1)
(A-4)
(A). In case EH-ETH requests to close connection
Description
(B). In case Host PC requests to close connection.
Description
*1
Fig. 7.2.1.1 Basic procedure to open connection
Chapter 7 Automatic data transmission
Host PC
(B-1)
(B-4)
(B). In case host PC requests to close connection
Segment
Sending FIN flag
Sending ACK flag
Sending FIN ACK flag
Sending ACK flag
Segment
Sending FIN flag
Sending ACK flag
Sending FIN ACK flag
Sending ACK flag
7-7
EH-ETH
(B-2)
(B-3)
EH-ETH status
Connection opened
(ESTABLISHED )
Waiting for a request
to close1
(FIN WAIT-1 )
Waiting for a request
to close1
(FIN WAIT-2 )
Waiting
(TIME WAIT ),
connection closed
(CLOSED )
EH-ETH status
Connection opened
(ESTABLISHED )
Waiting for a request
to close1
(FIN WAIT-1 )
Waiting for a request
to close1
(FIN WAIT-2 )
Waiting
(TIME WAIT ),
connection closed
(CLOSED )