Lantronix MSS1-T User manual

MSS Reference Manual
For Lantronix MSS1-T, MSS1-T2, and MSS485
Micro Serial Servers

Contents
i
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 .......................................................................... 1-2
1.2 Terms................................................................................................................. 1-3
1.3 Protocols............................................................................................................ 1-4
1.4 Software.............................................................................................................1-4
1.5 Configuration ................................................................................................... 1-5
2 Installation
2.1 MSS1 Components...........................................................................................2-1
2.2 MSS485 Components.......................................................................................2-2
2.3 Installation ........................................................................................................2-4
2.3.1 Power-up Diagnostics................................................................2-6
2.4 Is It Working?................................................................................................... 2-7
3 Getting Started
3.1 IP Address Configuration...............................................................................3-1
3.1.1 Using a BOOTP or RARP Reply...............................................3-1
3.1.2 Using an ARP Entry and the Ping Command........................3-2
3.1.3 Using the Serial Console............................................................3-3

ii
3.2 Incoming Logins ..............................................................................................3-3
3.2.1 Controlling Incoming Logins....................................................3-3
3.2.2 EZWebCon Login and Configuration...................................... 3-3
3.2.3 Other Incoming TCP/IP Logins...............................................3-4
3.2.4 Incoming LAT Logins ................................................................3-4
3.3 Serial Port Logins.............................................................................................3-4
3.4 Remote Console Logins ..................................................................................3-5
3.5 Logout................................................................................................................3-5
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 IP Configuration..........................................................................4-2
4.3.2 IPX Configuration.......................................................................4-4
4.3.3 LAT Configuration ..................................................................... 4-5
4.4 Serial Port Configuration................................................................................4-6
4.4.1 Access Mode................................................................................ 4-6
4.4.2 Baud Rate..................................................................................... 4-6
4.4.3 Parity, Character Size, and Stop Bits........................................4-6
4.4.4 Flow Control................................................................................4-7
4.4.5 Modems and Modem Signalling ..............................................4-7
4.4.6 Logouts.........................................................................................4-8
4.4.7 Preferred Port Service ................................................................4-9
4.4.8 Dedicated Port Service...............................................................4-9
4.4.9 Autostart ...................................................................................... 4-9
5 Using the MSS
5.1 Host-Initiated Connections ............................................................................5-1
5.1.1 Socket Connections.....................................................................5-1
5.1.2 LAT Connections ........................................................................ 5-2
5.1.3 Host Applications.......................................................................5-3
5.1.4 Code Examples............................................................................ 5-3

iii
5.2 Interactive Connections ..................................................................................5-3
5.2.1 Session Control............................................................................5-3
5.2.2 Outgoing Connections ...............................................................5-5
5.2.3 Status Displays............................................................................5-6
5.3 Emulating a Direct Serial Connection...........................................................5-8
5.4 Multihost Mode................................................................................................5-9
6 Commands
A Technical Support
B Troubleshooting
C Pinouts
D Specifications
E Updating Software
Index

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 .........................................................................1-2
1.2 Terms ................................................................................................................1-3
1.3 Protocols...........................................................................................................1-4
1.4 Software............................................................................................................1-4
1.5 Configuration ..................................................................................................1-5

Introduction
1 - 1
1 - Introduction
The MSS1-T and MSS1-T2 are multiprotocol serial servers that provide Ethernet connections for
personal computers, terminals, modems, and devices that would not otherwise be connected to a
network. The MSS485 is a multiprotocol serial server that provides Ethernet connections for
devices connected to an RS-485 network. All MSS products will collectively be referred to as MSS
in this manual.
The MSS can be used to start outbound Ethernet connections to hosts on TCP/IP, IPX/SPX, and
LAT networks. It can also provide interactive access to a device connected to its serial port.
However, unlike traditional print servers, the MSS does not provide printing protocols such as
LPR, RTEL, and PCONSOLE, or queueing support.
This manual explains how to install, configure, and use the MSS.
• The remainder of this chapter outlines MSS functionality. For MSS485
users, it explains RS-485 networking.
• 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 configuration.
• Chapter 4, Configuration , covers basic TCP/IP, NetWare, and LAT pro-
tocol configuration. It also explains serial port configuration, including
modem configuration.
• Chapter 5, Using the MSS , provides an overview of how to use the MSS
interactively and with host applications.
• Chapter 6, Commands , provides brief descriptions of each command in
the MSS command set, including syntax and restrictions.
• Appendices provided information on Technical Support, Troubleshoot-
ing, Pinouts, operating Specifications, and Updating Software.
Be sure to read the section of the configuration chapter that applies to the protocol you are using
(TCP/IP, IPX/SPX, or LAT).
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 file 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 fol-
lowing 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
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.
•
•
•
•
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 Terms
1 - 3
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 device’s receiver.
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 devices on an RS-485 network. An RS-
485 network typically has one master device.
Slave Any device on the RS-485 network that is not the master. An RS-485
network can have up to 31 slave devices.
Session Alogical connection to a service. A typical session is a terminal connected
to a host through the server.
Local mode The MSS user interface. It is used to issue configuration and session
management commands and to establish connections. When in Local
mode, users will see a Local> prompt.
TX
RX
RX
TX
TXA
TXB
RXB
RXA
Shield
Shield
TXA
TXB
RXB
RXA
Shield
Shield
ShA
A
B
B
TX
RX Sh
•
•
•
•
•
•
ShA
A
B
B
TX
RX Sh
•
•
•
•
•
•
ShA
A
B
B
TX
RX Sh
•
•
•
•
•
•
MSS
Slave Slave Slave
Slave
(Master)

Protocols Introduction
1 - 4
1.3 Protocols
A network protocol is a method of communicating over the Ethernet. Each protocol specifies a
certain arrangement of data in the Ethernet packets, and provides different services for its users.
The MSS supports the following protocols:
• TCP/IP
Support includes Telnet, Rlogin, UDP, and DNS. The Telnet terminal protocol,
supported on most UNIX systems, is an easy-to-use interface that creates terminal
connections to any network host supporting Telnet. Rlogin is a protocol that
allows users to initiate a TCP/IP login session. UDP (User Datagram Protocol) is a
connectionless protocol that results in smaller packet headers, no session over-
head, and the ability to send to multiple hosts. The MSS also supports the use of
Domain Name Servers (DNS), allowing a network nameserver to translate text
node names into numeric IP addresses.
The MSS also implements basic Simple Network Management Protocol (SNMP)
functionality. SNMP commands enable users, usually system administrators, to
get information from and control other nodes on a local area network (LAN), and
respond to queries from other network hosts. The MSS allows configuration of
one community name with read/write access.
• IPX/ SPX (NetWare)
The MSS provides IPX/SPX access to the serial device from NetWare and any
other IPX/SPX nodes. It allows users to download system files from NetWare
hosts and log into the MSS via NetWare for remote configuration.
The MSS supports all four NetWare frame types: Ethernet v2, Native mode, 802.2,
and 802.2 SNAP.
• Local Area Transport (LAT)
LAT is a protocol developed by Digital Equipment Corporation (DEC) for local
network connections and is supported on most DEC operating systems. The MSS
provides logins to remote hosts and host-initiated connections, as well as access to
the MSS serial port from LAT hosts.
1.4 Software
The CD-ROM shipped with the MSS contains operational software. It also contains EZWebCon
software which can be used to configure the unit.
The MSS is equipped with Flash ROM, so it is not necessary to download software each time the
unit boots. Software must only be reloaded if there is a problem with the Flash ROM, or if a new
software version is released. See Appendix E for more information.

Introduction Configuration
1 - 5
1.5 Configuration
Each MSS has a unique name and network address printed on its underside. The name is based on
the MSS Ethernet address and is referred to in the manual as MSS_xxxxxx . The xxxxxx string
represents the last six digits of the MSS Ethernet address. Be sure to note the Ethernet address
before configuring the unit.
When using IPX or LAT, it is possible to power up the MSS and have it work properly with no
additional configuration required. TCP/IP users must give the unit an IP address.
NOTE: For more information about methods used to configure an IP address, see page 3-1.
Lantronix has provided EZWebCon software to help users install and configure the MSS. It is also
possible to configure the MSS settings by logging into it over a network via Telnet or Rlogin. See
Chapter 3, Getting Started , for more information.
Additionally, the MSS can be configured to download a configuration file containing boot
commands from a NetWare or TCP/IP host at boot time. See the
Change Startup command for
more information.

2
Installation
2.1 MSS1 Components..........................................................................................2-1
2.2 MSS485 Components......................................................................................2-2
2.3 Installation........................................................................................................2-4
2.3.1 Power-up Diagnostics ...............................................................2-6
2.4 Is It Working? ..................................................................................................2-7

Installation MSS1 Components
2 - 1
2 - Installation
This chapter covers the installation of the MSS in an Ethernet network and the attachment of a
serial device (MSS1-T and MSS1-T2) or RS-485 devices and a serial console (MSS485). Basic
knowledge of networking installation is assumed. Read this section completely before continuing.
2.1 MSS1 Components
The MSS1 front panel has a male DB25 serial connector.
Figure 2-1: MSS1 Front Panel
The MSS rear panel has an RJ45 Ethernet connector, a BNC Ethernet connector (MSS1-T2 only), a
reset button, and a power connector.
Figure 2-2: MSS1 Rear Panel
NOTE: When the reset button is pressed and held during the power up and boot
procedures, the MSS returns to its factory default configuration.
The MSS1-T2 can autosense which Ethernet interface has been connected so long as a valid
network is present at boot time. Only one interface can be used at a time.
Four LEDs are located on the top of the unit. The first LED is a Power indicator, and should remain
green while the MSS is plugged in. The second is a network Link indicator, and should remain
green while the MSS is connected properly to a 10BASE-T network.
NOTE: The Link LED does not function for 10BASE2 connections.
Serial
DB25 Serial Port
10BaseT 6V DC
Reset
10Base2
Power Connector
Reset Button
BNC Ethernet Port
RJ45 Ethernet Port
(MSS1-T2 only)

MSS485 Components Installation
2 - 2
The remaining two LEDs indicate network ( OK ) and serial port ( Serial ) activity. They will blink
off, yellow, green, or red depending on the current activity.
Figure 2-3: MSS1 Top Panel Showing LEDs
NOTE: Although a red LED during boot mode usually signals an error, red LED patterns
are part of the normal operation of the MSS and are not necessarily indicative of
errors or dangerous operation.
2.2 MSS485 Components
The MSS485 front panel has a screw terminal block and an RJ45 port for an RS-485 serial
connection, as well as an RS-232 DB9 console port.
Figure 2-4: MSS485 Front Panel
The screw terminal block and RJ45 connector are wired in parallel. Only one of these ports can be
used at a time.
The MSS485 rear panel has an RJ45 Ethernet connector, a reset button, and a power connector.
Figure 2-5: MSS485 Rear Panel
6V DC Reset
Serial
Ethernet
MSS1-T
Micro Serial Server
Power
Link
OK
Serial
Power
Link
OK
Serial
LEDs
Console
DB9 Console Port
Screw Terminal Block RJ45 Port
(RS-485) (RS-485) (RS-232)
10BaseT 6V DC
Reset
Power ConnectorReset ButtonRJ45 Ethernet Port

Installation MSS485 Components
2 - 3
NOTE: When the reset button is pressed and held during the power up and boot
procedures, the MSS returns to its factory default configuration.
Four LEDs are located on the top of the unit. The first LED is a Power indicator, and should remain
green while the MSS is plugged in. The second is a network Link indicator, and should remain
green while the MSS is connected properly to a 10BASE-T network. The remaining two LEDs
indicate network ( OK ) and serial port ( Serial ) activity. They will blink off, yellow, green, or red
depending on the current activity.
Figure 2-6: MSS485 Top Panel Showing LEDs
NOTE: Although a red LED during boot mode usually signals an error, red LED patterns
are part of the normal operation of the MSS and are not necessarily indicative of
errors or dangerous operation.
The top of the MSS485 also contains an oval-shaped hole in the lower left corner. The hole
accommodates a screwdriver, which is needed to attach cabling wires to the screw terminal block.
Eight DIP switches are located on the bottom of the MSS485, along with a label that shows how to
configure them. DIP switch settings will be explained in step 5 of the installation instructions (see
page 2-5).
Figure 2-7: MSS485 Bottom Label Showing DIP Switches
MSS485
RS-485 Serial Server
POWER
LINK
OK
SERIAL
6VDC
10BASE-T RESET
SERIAL CONSOLE
SHLD
TXA
TXB
RXB
RXA
SHLD
POWER
LINK
OK
SERIAL
LEDs
Switch Group Functions
2 Wire 485
4 Wire 485
4 Wire 485 Termination
2 Wire 485 Termination
No Termination
2 or 4 Wire 485 RX Biasing
No RX Biasing
Ground Shield
Float Shield
6
8
7
45
23
1
23
1674 58

Installation Installation
2 - 4
2.3 Installation
Figure 2-8 and Figure 2-9 show example hardware layouts.
Figure 2-8: MSS1 Network Layout
Figure 2-9: MSS485 Network Layout
1. Select a location.
The MSS should be positioned close to the device(s) it will be servicing but out
of the way of everyday activity. Since powering down the unit will terminate
any active sessions, it may be desirable to place the server in a location secure
from user access. Also be aware of the unit’s environmental operating limits and
cabling limits. See Appendix D for details.
2. Connect the MSS to a serial device (MSS1) or an RS485 network (MSS485).
The MSS1 is designed to connect to an RS232-based serial device. Connect one
end of a serial cable to the DB25 connector on the front of the MSS. Connect the
other end of the cable to your serial device’s DB25 port.
Initially, you may want to connect a terminal to the serial port. The terminal will
display any error messages and will allow you to view commands as you
configure the MSS.
NOTE: The serial port is initially set for 9600 baud, 8 data bits, one stop bit, and no parity.
10BASE-T Hub 10BASE2
Repeater
MSS1-T
MSS1-T2
Serial Device
Serial Device
Twisted Pair
Thin Coax
File Sun MicroVAX
Server
Ethernet
MSS485
Ethernet
Bank of RS-485-compliant Devices
Ethernet
Hub