CSE-H21 User’s Manual Ver. 1.2
Sollae Systems Co., Ltd.
- 33 -
http://www.sollae.co.kr
5.2
T2S
In T2S mode, the CSE-H21 functions as a server.
When a host connects to predefined local port, the CSE-H21 accepts a TCP connection. When
the ezTCP accepts TCP connection, then the TCP connection is established. After connection is
established, TCP/IP processing is performed on the data coming to the serial port, which is then
transmitted to the remote host. And the TCP/IP data coming from the remote host is TCP/IP-
processed and transmitted to the serial port to establish data communication.
Remote Host
Serial Device
ezTCP
Listen on
local port
Request TCP connection
Accept TCP co
nnection
ack
DATA
“
ABC
”
DATA
“
ABC
”
(TCP/IP)
DATA
“
DEF
”
(TCP/IP)
DATA
“
DEF
”
connected
<T2S Mode>
Figure 5-1 T2S Mode
5.2.1
TCP Connection
If a host connects to the pre-defined [Local Port] of CSE-H21, the host can communicate
bi-directionally.
5.2.2
Connection Limitation
CSE-H21 has two connection limitation functions. Those can be set by the [Option] tab
of the ezManager.
Allowed Ethernet Address
If user sets the [Allowed Ethernet Address], the only specified host can access the CSE-
H21.
Allowed IP
When the [Allowed IP] is set, the only hosts that are specified by [Allowed IP] and [Net
Mask] can connect to the CSE-H21
