Lantronix MSS4 Installation Guide

Using the MSS COM Port Redirector
5-12
Wiring Requirements
Serial signals work differently when one or more of the MSS serial ports is in modem mode. First, the MSS
will enable DTRWait and will not drive DTR until a valid connection is made with the ATDT command.
Second, the MSS will drop DTR whenever the TCP session is disconnected. DSRLogout is enabled
implicitly. The MSS DTR signal will be used as a simulated CD signal to the attached serial device.
When using an MSS serial port in modem mode:
 The serial device’s DTR goes out to BOTH its own DSR in and the MSS DSR in. When the device
asserts its DTR, it will see its DSR asserted. That way the device thinks that the “modem” (the MSS)
is ready to accept commands all the time and the MSS can close the network connection when the
device disconnects.
 The MSS DTR out goes to the serial device’s CD in. That way the MSS can signal the serial device
that there is a valid connection, and the serial device will know it can send data to the remote device.
COM Port Redirector
The Lantronix Com Port Redirector application allows PCs to share modems and other serial devices
connected to an MSS using Microsoft Windows applications.
The Redirector intercepts communications to specified PC COM ports and sends them over a network
connection to one of the MSS serial ports. This enables the PC to use an MSS serial port as if it were one
of the PC COM ports.
Note: The redirector works over 802.11 connections.
The COM Port Redirector software is included on the distribution CD-ROM.

Lantronix MSS4 Specifications

General

Brand	Lantronix
Model	MSS4
Category	Server
Language	English