Senatek LS100 User Manual

 

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The LS100 works as a TCP client, and the default TCP state is [Closed] in this mode. The remote host 

will be either Ethernet-Serial communication devices acting as a TCP server or a socket  program 

acting as a TCP server running on users’ PC. 

 

 

[Closed] --> [Sync-Sent] --> [Established] --> [Data] --> [Closed] 

At start-up,  an  initial  TCP state is  [Closed]. If there is any incoming data through the serial port, the 

LS100 will try to connect to a user-defined remote host. Then, the state will be changed to [Sync-Sent], 

which means the connection request is  being  sent. If the remote host accepts the request, the state 

will be changed into [Established], which means a session has been opened. For a while, data will be 

transferred between the hosts. This is [Data] state. The session will be disconnected due to the 

request of one of them, which is its original state, [Closed].   

 

 

Whenever the serial device sends data through the serial port of the LS100,  data  will be 

accumulated to the serial port buffer of the LS100. If the  internal serial port buffer is full or inter-

character time interval reaches to the time  specified as  inter-character timeout value, it tries to 

connect to the user-defined IP address of the remote host, if TCP session is not established yet. If 

the LS100 succeeds  in  connecting to the remote host, the data in the serial port buffer will be 

transferred to the host. Otherwise, all the data stored in the buffer will be cleared. 

The connected session will be disconnected when the remote host sends disconnection request 

or when no data transfer activity is found through the serial port for certain amount of time, which 

is  “Inactivity timeout”. All the data remained  in the serial port buffer will be cleared when it is 

disconnected. 

All the incoming TCP connection requests will be rejected in TCP client mode. 

It  Cyclic Connection function is enabled, the LS100 will make an attempt to connect to the user-

defined remote host at certain interval even if there’s no incoming serial data from the device. If 

the remote host prepares certain data, it will be transferred to the serial device via its serial port