Sena LS100W User Manual download pdf (Page 33)

Sync-Sent

If the LS100W sends a connection request to a remote host, the state is changed from [Closed] to

[Sync-Sent]. This state is maintained until the remote host accepts the connection request. This

state is valid only in TCP client mode.

Established

It represents “an open connection”. If one of the hosts accepts a connection request from the

other host, the connection is opened and state is changed into [Established].

Data

When it is in [Established] state, data from a host will be transferred to the other one. For easier

understanding of the TCP session operation, we called the state as [Data] state whenactual data

transfer is performed. Actually, the [Data] mode is a part of [Established] state as is described in

the RFC 793 [Transmission Control Protocol]. This is a normal state for the data transfer phase of

the connection.

5.1 TCP Server Mode Operations

5.1.1 Overview

The LS100W works as a TCP server, and the default TCP state is [Listen] in this mode. The LS100W

supports only one TCP socket connection per one serial port. If a connection is currently established,

the additional connection requests will be rejected. The remote host will be either Ethernet-Serial

communication devices acting as a TCP client or a socket program acting as a TCP client running on

users’PC.

1) Typical State Transition

[Listen] --> [Sync-Received] --> [Established]--> [Data] --> [Closed] --> [Listen]

At start-up, an initial TCP state is [Listen]. If there is any incoming TCP connection request, the state

will be changed into [Sync-Received], then [Established], which means a session is opened. For a

while, data will be transferred between the hosts. This is the [Data] state. The session will be

disconnected due to the request of one of them, which is [Closed] state. And then, the state is

automatically changed to its original state, [Listen].

1 2 ... 28 29 30 31 32 33 34 35 36 37 38 ... 49 50

No comments

Sena LS100W User Manual Page 33