User`s manual

WE-2100T Series User’s Manual Selecting an Operation Mode

4-2

Overview

The WE-2100T connects serial devices to the wireless LAN. It has a built-in TCP/IP stack that

saves you the effort of programming networking protocols. Simply select the proper operating

mode to allow your computer to access, manage, and configure your serial device over the

Internet.

Traditional SCADA and data collection systems collect data from various instruments over serial

connections (RS-232/422/485). Since WE-2100T is designed to convert between serial and

Ethernet signals, both local and remote devices can be connected to a standard TCP/IP network

and made accessible to SCADA and data collection systems.

Real COM and RFC2217 modes allow serial-based software to access the module’s serial port as

if it were a local serial port on a PC. These modes are appropriate when your application relies on

Windows or Linux software that was originally designed for locally attached COM or TTY

devices. With these modes, you can access your devices from the network using your existing

COM/TTY-based software, without investing in additional software.

Three different socket modes are available for user-developed socket programs: TCP Server, TCP

Client, and UDP Server/Client. For TCP applications, the appropriate mode depends on whether

the connection will be hosted or initiated from the module’s serial port or from the network. The

main difference between the TCP and UDP protocols is that TCP guarantees delivery of data by

requiring the recipient to send an acknowledgement to the sender. UDP does not require this type

of verification, making it possible to offer speedier delivery. UDP also allows multi-unicasting of

data to groups of IP addresses and would be suitable for streaming media or non-critical messaging

applications such as LED message boards.

TCP Server Mode

In TCP Server mode, the module’s serial port is

assigned an IP:port address that is unique on your

TCP/IP network. It waits for the host computer to

establish a connection to the attached serial

device. This operation mode also supports up to

four simultaneous connections, so multiple hosts

can collect data from the attached device at the

same time.

Data transmission proceeds as follows:

1. A host requests a connection to the module’s

serial port.

. Once the connection is established, data can

be transmitted in both directions—from the

host to the device, and from the device to the

host.