al server family uses serial-to-Ethernet
communication software that has over 5 years of real-world feedback and
development behind it.
Lantronix is constantly improving the capabilities of our products, and we
encourage you to take advantage of new features through our FREE software
upgrades (available via ftp over the internet or BBS.)
Our Flash ROM products, including this MSS, provide the simplest means for
upgrades and installation. I hope you nd this manual easy to use, and thorough
in its explanation of the powerful features you can now access on your network.
Brad Freeburg
President
i

Contents

1
Introduction

1.1 RS-485 Networking Overview .................................1-2
1.1.1 RS-485 Protocols....................................1-2
1.1.2 Two-wire Mode.....................................1-2
1.1.3 Four-wire Mode ....................................1-3
1.2 Terms ...........................................................................1-4
1.3 Protocols......................................................................1-5
1.4 Software ......................................................................1-6
1.5 Configuration .............................................................1-6

2
Installation

2.1 MSS485 Components.................................................2-1
2.2 Installation ..................................................................2-3
2.2.1 Power-up Diagnostics ..........................2-6
2.3 Is It Working? .............................................................2-7
ii

3
Getting Started

3.1 IP Address Configuration.........................................3-2
3.1.1 Using a BOOTP or RARP Reply .........3-2
3.1.2 Using an ARP Entry and the Ping Command3-
2
3.1.3 Using the Serial Console ......................3-3
3.2 Incoming Logins ........................................................3-4
3.2.1 Controlling Incoming Logins ..............3-4
3.2.2 EZWebCon Login and Configuration3-4
3.2.3 Other Incoming TCP/IP Logins .........3-4
3.2.4 Incoming LAT Logins ..........................3-5
3.3 Serial Port Logins.......................................................3-5
3.4 Remote Console Logins ............................................3-5
3.5 Starting Outbound Connections..............................3-6
3.5.1 Telnet ......................................................3-6
3.5.2 SPX ..........................................................3-7
3.5.3 LAT .........................................................3-7
3.6 Logout..........................................................................3-7

4
Configuration

4.1 Command Set .............................................................4-1
4.2 System Passwords .....................................................4-1
4.2.1 Privileged Password.............................4-1
4.2.2 Login Password.....................................4-2
4.3 Protocol Configuration .............................................4-2
4.3.1 TCP/IP Parameters ..............................4-2
4.3.2 IPX/SPX Parameters ............................4-3
4.3.3 LAT Parameters ....................................4-4
4.4 Serial Port Configuration.........................................4-4
iii

5
Using the MSS

5.1 Host-Initiated Connections ......................................5-2
5.1.1 Socket Connections...............................5-2
5.1.2 LAT Connections ..................................5-3
5.1.3 Host Applications .................................5-4
5.1.4 Code Examples......................................5-4
5.2 Interactive Connections ............................................5-5
5.2.1 Session Control......................................5-5
5.2.2 Outgoing Connections .........................5-7
5.2.3 Status Displays ......................................5-9
5.3 Emulating a Direct Serial Connection.....................5-11
5.4 Multihost Mode..........................................................5-13

A
Technical Support

B
Troubleshooting

C
Pinouts

D
Specifications

Warranty Statement

Declaration of Conformity

Index

Introduction


1 - 1

1 - Introduction

The MSS485 is a multiprotocol serial server that provides Ethernet
connections for devices connected to an RS-485 network.
This manual explains how to install the MSS. The remainder of this chapter outlines MSS functionality. Chapter 2,

Installation

, explains how to install the MSS hardware
and boot the server. Chapter 3,

Getting Started

, details different ways to log into the MSS
and prepare the server for conguration. Chapter 4,

Conguration

, covers basic conguration. Chapter 5,

Using the MSS

, provides an overview of how to use the
MSS interactively and with host applications. Appendices provide information on Technical Support,
Troubleshooting, Pinouts, and Specications. The hypertext version of this manual, located on CD-ROM,
includes more specic information about conguring and using the
MSS and reloading MSS software.
Be sure to read the section of the conguration chapter that applies to the
protocol you are using (TCP/IP, IPX/SPX, or LAT).
For more detailed information on the MSS, including a complete
command reference, see the

MSS Reference Manual

located on the CD in
HTML, PDF, and PostScript formats.
To access the HTML version of the Reference Manual on the CD, use your
web browsers

Open

or

Open File

command (usually in the

File

menu)
to open the le

index.htm

in the root directory of the CD. Then click on the
link to the

MSS Reference Manual

.
The PostScript and PDF versions of the MSS485 manuals are located in
the

manuals

directory of the CD. Use the Adobe Acrobat Reader (widely
available on the Internet at no charge) to read and print all or parts of the
manual from the le

mssref.pdf

.
RS-485 Networking Overview
Introduction

1 - 2

1.1 RS-485 Networking Overview

The RS-485 standard allows a transmission line to be shared like a party
line. As many as 32 devices can share the multidrop network. Typically,
one device is the master and the other devices are slaves. There are a few
important things to note about RS-485 networking with the MSS. The MSS can be used in either two-wire or four-wire mode. Refer
to the following sections to determine which mode to use. The maximum RS-485 network cabling length (without repeaters)
is 4,000 feet. Lantronix recommends the use of shielded twisted-
pair cabling.

1.1.1 RS-485 Protocols

A large number and variety of protocols run over RS-485. However, the
MSS does not convert or interpret serial data. It only moves data between
serial and Ethernet. Any RS-485 protocol will have to be implemented by
host software.

1.1.2 Two-wire Mode

In two-wire mode, the MSS operates in half duplex: one pair of wires
shares transmit and receive signals, and an optional third wire can be
used for shield/ground. The main advantage of using two-wire mode is
reduced cabling costs.

Figure 1-1:

Example Two-wire Mode Network
TXA
TXB
TX
RX
Shield
A
A
B
B
A
B
B
A
RX
TX
Shield
Shield
Shield A
B
A
B
TX
RX
Sh
Sh
A
B
A
B
TX
RX
Sh
Sh
A
B
A
B
TX
RX
Sh
Sh Shield
Slave
Slave
Slave
Slave
MSS
(Master)
Introduction
RS-485 Networking Overview

1 - 3

On a two-wire RS-485 network, the MSS must turn its transmitter on
when it is ready to send data and then off a certain period of time after
the data has been sent so that the line is available to receive again. At
most baud rate settings, the timing delay is typically one character length
with a maximum of 1.5 character lengths.

NOTE:

For 600 baud and 4800 baud operation, the timing delay is
doubled.

1.1.3 Four-wire Mode

In four-wire mode, the MSS operates in full duplex: one pair of wires
functions as the transmit pair, another pair of wires functions as the
receive pair, and there is a shield/ground wire for each pair. In a four-
wire RS-485 network, one device, such as the MSS, acts as master while
the other devices are slaves.

Figure 1-2:

Example Four-wire Mode Network
It is important to connect the transmitter of the master device to the wire
that is connected to the receive terminals on the slave devices, and
connect the receiver of the master device to the wire that is connected to
the transmit terminals on the slave devices. In essence, the master device
will be connected to the slave devices with a

swapped

cable.
The MSS transmitter is always driving and the receiver is always enabled,
so the MSS is able to send and receive data simultaneously. The
advantages of four-wire mode are double the throughput of two-wire
mode and a guaranteed open path to each slave devices receiver.
TX
RX
RX
TX
TXA
TXB
RXB
RXA
Shield
Shield
TXA
TXB
RXB
RXA
Shield
Shield
Sh
A
A
B
B
TX
RX
Sh
Sh
A
A
B
B
TX
RX
Sh
Sh
A
A
B
B
TX
RX
Sh
MSS
Slave
Slave
Slave
Slave
(Master)
Terms
Introduction

1 - 4

1.2 Terms

In this manual, the following terms are used to describe parts of a network.

Host

A computer attached to the network. The term
host is generally used to denote interactive
computers, or computers that people can log into.

Node

Any intelligent device directly connected to the
Ethernet network such as a host, a printer, or a
terminal server. All nodes have their own Ethernet
addresses. The MSS is a node. Devices connected
to the MSS are not nodes.

Master

The device that controlls all other de