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Introduction
NPort Express’s new Ethernet Modem operation mode is designed to provide true modem emulation, in
which NPort Express emulates a regular serial modem, accepting AT commands for dial-in/out service
and then transparently passing raw data in/out after the user initiates the Ethernet Modem mode.
After a connection is established, NPort Express acts as a gateway between the serial line and Ethernet
LAN, making it possible for raw RS-232/422/485 data to travel across a local LAN. After receiving raw
serial data, NPort Express will prefix and postfix a TCP/IP header and trailer, and then send it out to the
Ethernet medium. Once the control host receives the TCP/IP data frame, the NOS (Network Operating
System) recovers the raw data by decoding the TCP/IP header and trailer. The user can easily capture the
raw serial data from the Ethernet medium using Telnet or some customized TCP/IP socket program,
providing an ideal long-distance serial data transmission so lution between host and serial device.
Application Architecture
Two typical applications
:
(1)
(2)
.
Note:
If the DCD signal for carrier detection is required, you will need to use a cable to connect
NPort Express’s serial port to your device/PC, as shown here:
