Moxa Technologies DA-681 Series User manual

DA-681 Series Linux Manual
Fourth Edition, August 2012
www.moxa.com/product
© 2012 Moxa Inc. All rights reserved.

DA-681 Series Linux Manual
The software described in this manual is furnished under a license agreement and may be used only in accordance with
the terms of that agreement.
Copyright Notice
© 2012 Moxa Inc. All rights reserved.
Trademarks
The MOXA logo is a registered trademark of Moxa Inc.
All other trademarks or registered marks in this manual belong to their respective manufacturers.
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Information in this document is subject to change without notice and does not represent a commitment on the part of
Moxa.
Moxa provides this document as is, without warranty of any kind, either expressed or implied, including, but not limited
to, its particular purpose. Moxa reserves the right to make improvements and/or changes to this manual, or to the
products and/or the programs described in this manual, at any time.
Information provided in this manual is intended to be accurate and reliable. However, Moxa assumes no responsibility for
its use, or for any infringements on the rights of third parties that may result from its use.
This product might include unintentional technical or typographical errors. Changes are periodically made to the
information herein to correct such errors, and these changes are incorporated into new editions of the publication.
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Table of Contents
1. Introduction...................................................................................................................................... 1-1
Overview ...........................................................................................................................................1-2
Product Features ................................................................................................................................ 1-2
Software Specifications........................................................................................................................ 1-2
Read-only Root File System .................................................................................................................1-3
Software Components ......................................................................................................................... 1-3
2. Software Configuration ..................................................................................................................... 2-1
Starting from a VGA Console................................................................................................................2-2
Connecting from a Telnet Console.........................................................................................................2-2
Connecting from an SSH Console.......................................................................................................... 2-3
Windows Users ........................................................................................................................... 2-4
Linux Users ................................................................................................................................2-4
Adjusting the System Time .................................................................................................................. 2-4
Setting the Time Manually ............................................................................................................2-4
NTP Client .................................................................................................................................. 2-5
Updating the Time Automatically ...................................................................................................2-6
Enabling and Disabling Daemons ..........................................................................................................2-7
Setting the Run-Level..........................................................................................................................2-8
Cron—Daemon for Executing Scheduled Commands................................................................................2-9
Inserting a SATA Hard Drive into the Computer .................................................................................... 2-10
Inserting a USB Storage Device into the Computer ............................................................................... 2-11
Inserting a CompactFlash Card into the Computer ................................................................................ 2-12
Checking the Linux Version ................................................................................................................ 2-12
APT—Installing and Removing Packages .............................................................................................. 2-13
WDT (Watchdog Timer) ..................................................................................................................... 2-14
3. Managing Communications ............................................................................................................... 3-1
Changing the Network Settings ............................................................................................................3-2
Changing the “interfaces” Configuration File ...................................................................................3-2
Adjusting IP Addresses with “ifconfig” ............................................................................................3-3
Telnet Server .....................................................................................................................................3-3
Enabling the Telnet Server ...........................................................................................................3-3
Disabling the Telnet Server........................................................................................................... 3-4
FTP Server .........................................................................................................................................3-4
Enabling the FTP Server ............................................................................................................... 3-4
Disabling the FTP Server ..............................................................................................................3-4
DNS Client .........................................................................................................................................3-4
etc/hostname .............................................................................................................................3-5
etc/resolv.conf ............................................................................................................................3-5
etc/nsswitch.conf ........................................................................................................................ 3-5
Apache Web Server.............................................................................................................................3-6
Default Homepage....................................................................................................................... 3-6
Saving Web Pages to a USB Storage Device....................................................................................3-7
IPTABLES ..........................................................................................................................................3-8
IPTABLES Hierarchy................................................................................................................... 3-10
IPTABLES Modules..................................................................................................................... 3-11
Observe and Erase Chain Rules ................................................................................................... 3-11
Define Policy for Chain Rules....................................................................................................... 3-12
Append or Delete Rules.............................................................................................................. 3-12
NAT (Network Address Translation)..................................................................................................... 3-13
NAT Example ............................................................................................................................ 3-14
Enabling NAT at Bootup ............................................................................................................. 3-14
PPP (Point to Point Protocol)............................................................................................................... 3-15
Connecting to a PPP Server over a Simple Dial-up Connection......................................................... 3-15
Connecting to a PPP Server over a Hard-wired Link ....................................................................... 3-16
Checking the Connection ............................................................................................................ 3-16
Setting up a Machine for Incoming PPP Connections ...................................................................... 3-17
PPPoE.............................................................................................................................................. 3-18
NFS (Network File System) Client ....................................................................................................... 3-20
SNMP (Simple Network Management Protocol) ..................................................................................... 3-21
OpenVPN ......................................................................................................................................... 3-22
Ethernet Bridging for Private Networks on Different Subnets........................................................... 3-22
Ethernet Bridging for Private Networks on the Same Subnet ........................................................... 3-26
Routed IP ................................................................................................................................. 3-26
4. System Recovery............................................................................................................................... 4-1
Recovery Environment ........................................................................................................................4-2
Recovery Procedure ............................................................................................................................4-2

1
1. Introduction
Thank you for purchasing the Moxa DA-681 Series of x86 ready-to-run embedded computers. This manual
introduces the software configuration and management of the DA-681-LX, which runs the Linux operating
system. For hardware installation, connector interfaces, setup, and upgrading the BIOS, please refer to the
“DA-681 Series Hardware User’s Manual.”
Linux is an open, scalable operating system that allows you to build a wide range of innovative, small footprint
devices. Software written for desktop PCs can be easily ported to the embedded computer with a GNU cross
compiler and a minimum of source code modifications. A typical Linux-based device is designed for a specific
use, and is often not connected to other computers, or a number of such devices connect to a centralized,
front-end host. Examples include enterprise tools such as industrial controllers, communications hubs,
point-of-sale terminals, and display devices, which include HMIs, advertisement appliances, and interactive
panels.
The following topics are covered in this chapter:

Overview

Product Features

Software Specifications

Read-only Root File System

Software Components

DA-681 Linux Introduction
1-2
Overview
The DA-681 embedded computer is based on the Intel Celeron M processor and 910GMLE chipset, which
supports standard X86 VGA, USB, PS/2 keyboard/mouse, 6 10/100 Mbps LAN ports, and SATA disk interface.
In addition, the DA-681 supports a CompactFlash Socket and pre-installed embedded ready-to-run operating
system. Programmers will find the full-function development kit a great benefit for developing software and
building reliable communication applications.
The housing is a standard 1U, 19-inch wide rack-mounted rugged enclosure. This robust, rack-mountable
design provides the hardened protection needed for industrial environment applications.
Moreover, the DPP-T models are in full compliance with IEC 61850-3 standards to meet the demands of power
substation automation.
Product Features
The DA-681 Series Basic System has the following features:
•IEC 61850-3 certified for power substation automation systems (DPP-T models only)
•Intel Celeron M 1 GHz processor with 400 MHz FSB
•Intel 910GMLE + ICH6M chipset
•200-pin DDR2 SODIMM socket supporting DDR2 400 up to 1 GB (built-in 512 MB)
•6 Ethernet ports for network redundancy
•1 CompactFlash socket
•1 SATA connector for storage expansion
•4 RS-232 and 8 RS-485 serial ports (supports most nonstandard baudrates in this range)
•2 USB 2.0 ports for high speed peripherals
•19-inch rackmount, 1U high form factor
•Fanless Design
•100/240 VAC/VDC power input (single power and dual power models available)
ATTENTION
R
efer to section “Baud Rate Speed” for calculation of baud rate speed supported.
Software Specifications
The Linux operating system pre-installed on the DA-681 embedded computer is the Debian Etch
4.0r2 distribution. The Debian project is a worldwide group of volunteers who endeavor to produce an
operating system distribution that composed entirely of free software. The Debian GNU/Linux follows the
standard Linux architecture, making it easy to use programs that meet the POSIX standard. In addition to
Standard POSIX APIs, device drivers for Moxa UART and other special peripherals are also included. An
example software architecture is shown below:

DA-681 Linux Introduction
1-3
ATTENTION
Refer to
http://www.debian.org/ and http://www.gnu.org/ for information and documentation of the
Debian
GNU/Linux and free software concept.
ATTENTION
The a
bove software architecture is only an example. Different models or different build revisions of the
Linux
operating system may include components
not shown in the above graphic.
Read-only Root File System
The pre-installed root file system is protected in a read-only partition to prevent file system crash problems
normally caused by power loss. But some directories or files, such as /home,
/root, /var, /etc/network/, /etc/ppp/,/ect/openvpn/, and /etc/resolv.conf, which need write
permission, are located in another writable partition and formatted with the EXT2 file system. You can
read/write above files or directories directly without re-mounting it.
Software Components
The DA-681-LX pre-installed Debian Etch 4.0r2 Linux distribution has the following software components:
Component Version Description
acpid 1.0.4-5 Utilities for using ACPI power management
adduser 3.102 Add and remove users and groups
apache2 2.2.3-4+etch6 Next generation, scalable, extendable web server
apache2-mpm-prefork 2.2.3-4+etch6 Traditional model for Apache HTTPD 2.1
apache2-utils 2.2.3-4+etch6 Utility programs for webservers
apache2.2-common 2.2.3-4+etch6 Next generation, scalable, extendable web server
apt 0.6.46.4-0.1 Advanced front-end for dpkg
apt-utils 0.6.46.4-0.1 APT utility programs
aptitude 0.4.4-4 Terminal-based apt frontend
base-files 4 Debian base system miscellaneous files
base-passwd 3.5.11 Debian base system master password and group
bash 3.1dfsg-8 The GNU Bourne Again SHell
binutils 2.17-3 The GNU assembler, linker and binary utilities
bridge-utils 1.2-1 Utilities for configuring the Linux ethernet bridge
RS-232/422/485, Ethernet, PCMCIA, CompactFlash, SATA, USB
Memory Control, Schedule, Process
PCMCIA, CF, WLAN, USB, UART, RTC, VGA
TCP, IP, UDP, CMP, ARP, HTTP, SNMP, SMTP
Daemon (Apache, Telnet, FTPD)
Application Interface (POSIX, Socket, Secure Socket)
User Applications
File
System
Hardware
Micro Kernel
Device Driver
Protocol Stack
API
AP
Linux
Kernel

DA-681 Linux Introduction
1-4
Component Version Description
bsdmainutils 6.1.6 Collection of more utilities from FreeBSD
bsdutils 2.12r-19etch1 Basic utilities from 4.4BSD-Lite
busybox 1.1.3-4 Tiny utilities for small and embedded system
console-common 0.7.69 Basic infrastructure for text console configuration
console-data 1.01-7 Keymaps, fonts, charset maps, fallback table for
console-tools
console-tools 0.2.3dbs-65 Linux console and font utilities
coreutils 5.97-5.3 The GNU core utilities
cpio 2.6-18.1+etch1 GNU cpio -- a program to manage archives of files
cpp
4.1.1-15
The GNU C preprocessor (cpp)
cpp-4.1 4.1.1-21 The GNU C preprocessor
cron 3.0pl1-100 Management of regular background processing
debconf 1.5.11etch1 Debian configuration management system
debconf-i18n 1.5.11etch1 Full internationalization support for debcon
debian-archive-keyring 2007.07.31~etc GnuPG archive keys of the Debian archive
debianutils 2.17 Miscellaneous utilities specific to Debian
dhcp3-client 3.0.4-13 DHCP Client
dhcp3-common 3.0.4-13 Common files used by all the dhcp3* packages
dictionaries-common 0.70.10 Common utilities for spelling dictionary tools
diff 2.8.1-11 File comparison utilities
dmidecode 2.8-4 Dump Desktop Management Interface data
dnsutils 9.3.4-2etch1 Clients provided with BIND
dpkg 1.13.25 Package maintenance system for Debian
dselect 1.13.25 User tool to manage Debian packages
e2fslibs 1.39+1.40-WIP-2006
.
11.14+dfsg-2etch1 ext2 filesystem libraries
e2fsprogs 1.39+1.40-WIP-2006
.
11.14+dfsg-2etch1 ext2 file system utilities and libraries
findutils 4.2.28-1etch1 Utilities for finding files--find, xargs, an
ftp
0.17-16
The FTP client
g++ 4.1.1-15 The GNU C++ compiler
g++-4.1 4.1.1-21 The GNU C++ compiler
gcc 4.1.1-15 The GNU C compiler
gcc-4.1 4.1.1-21 The GNU C compiler
gcc-4.1-base 4.1.1-21 The GNU Compiler Collection (base package)
gnupg 1.4.6-2 GNU privacy guard - a free PGP replacement
gpgv 1.4.6-2 GNU privacy guard - signature verification tool
grep 2.5.1.ds2-6 GNU grep, egrep and fgrep
grub 0.97-27etch1 GRand Unified Bootloader
gzip
1.3.5-15
The GNU compression utility
hostname 2.93 Utility to set/show the host name or domain
ifrename 28-1+etchnhalf Rename network interfaces based on various static criteria
ifupdown 0.6.8 High level tools to configure network interfaces
initramfs-tools 0.85i Tools for generating an initramfs
initscripts 2.86.ds1-38+et Scripts for initializing and shutting down the system
iproute 20061002-3 Professional tools to control the networking in Linux kernels
iptables 1.3.6.0debian1 Administration tools for packet filtering and NAT netfilter
and iptables provide a Linux kernel framework for stateful
and stateless packet filtering, network and port address
translation, and other IP packet manipulation. The
framework is the successor to ipchains.
iputils-ping 20020927-6 Tools to test the reachability of network hosts

DA-681 Linux Introduction
1-5
Component Version Description
klibc-utils 1.4.34-2 Small statically-linked utilities built with klibc
klogd 1.4.1-18 Kernel Logging Daemon
libacl1 2.2.41-1 Access control list shared library
libattr1 2.4.32-1 Extended attribute shared library
libbind9-0 9.3.4-2etch1 BIND9 Shared Library used by BIND
libblkid1 1.39+1.40-WIP-2006
.
11.14+dfsg-2etch1 block device id library
klibc 1.0.3-6 Small statically-linked utilities built with klibc
libc6 2.3.6.ds1-13etch5 GNU C Library: Shared libraries
libc6-dev
2.3.6.ds1-13etch5
GNU C Library: Development Libraries and Header Files
libc6-i686 2.3.6.ds1-13etch5 GNU C Library: Shared libraries [i686 optimized]
libcap1 1.10-14 Support for getting/setting POSIX.1e capabilities
libcomerr2 1.39+1.40-WIP-2006
.
11.14+dfsg-2etch1 common error description library
libconsole
0.2.3dbs-65
Shared libraries for Linux console and font
libcupsys2 1.2.7-4etch2 Common UNIX Printing System(tm) - libs
libdb4.2 4.2.52+dfsg-2 Berkeley v4.2 Database Libraries [runtime]
libdb4.3 4.3.29-8 Berkeley v4.3 Database Libraries [runtime]
libdb4.4 4.4.20-8 Berkeley v4.4 Database Libraries [runtime]
libdevmapper1.02 1.02.08-1 The Linux Kernel Device Mapper userspace library
libdns22 9.3.4-2etch1 DNS Shared Library used by BIND
libedit2 2.9.cvs.20050518-2.
2
BSD editline and history libraries
libevent1 1.1a-1 An asynchronous event notification library
libgc1c2 6.8-1 Conservative garbage collector for C and C++
libgcc1 4.1.1-21 GCC support library
libgcrypt11 1.2.3-2 LGPL Crypto library - runtime library
libgdbm3 1.8.3-3 GNU dbm database routines (runtime version)
libgnutls13 1.4.4-3 The GNU TLS library - runtime library
libgpg-error0
1.4-1
Library for common error values and messages
libgpmg1 1.19.6-25 General Purpose Mouse - shared library
libgssapi2 0.10-4 A mechanism-switch gssapi library
libidn11 0.6.5-1 GNU libidn library, implementation of IETF I
libisc11 9.3.4-2etch1 ISC Shared Library used by BIND
libisccc0 9.3.4-2etch1 Command Channel Library used by BIND
libisccfg1 9.3.4-2etch1 Config File Handling Library used by BIND
libiw28 28-1 Wireless tools - library
libklibc 1.4.34-2 Minimal libc subset for use with initramfs
libkrb53 1.4.4-7etch4 MIT Kerberos runtime libraries
libldap2
2.1.30-13.3
OpenLDAP libraries
liblocale-gettext-perl 1.05-1 Using libc functions for internationalization in Perl
liblockfile1 1.06.1 NFS-safe locking library, includes dotlockfile program
liblwres9 9.3.4-2etch1 Lightweight Resolver Library used by BIND
liblzo1 1.08-3 Data compression library (old version)
liblzo2-2 2.02-2 Data compression library
libmagic1 4.17-5etch3 File type determination library using “magic” numbers
libmysqlclient15off 5.0.32-7etch5 mysql database client library
libncurses5 5.5-5 Shared libraries for terminal handling
libncursesw5 5.5-5 S Shared libraries for terminal handling
(wide character support)
libnet-lite-ftp-perl 0.47-2 Perl FTP client with support for TLS
libnet-ssleay-perl 1.30-1 Perl module for Secure Sockets Layer (SSL)

DA-681 Linux Introduction
1-6
Component Version Description
libnet-telnet-perl 3.03-1 Script telnetable connections
libnewt0.52 0.52.2-10 Not Erik’s Windowing Toolkit - text mode windowing with
slang
libnfsidmap2 0.18-0 An nfs idmapping library
libopencdk8 0.5.9-2 Open Crypto Development Kit (OpenCDK) (runtime)
libpam-modules 0.79-5 Pluggable Authentication Modules for PAM
libpam-runtime 0.79-5 Runtime support for the PAM library
libpam0g 0.79-5 Pluggable Authentication Modules library
libpcap0.8 0.9.5-1 System interface for user-level packet capture
libpci2
2.1.11-3
Obsolete shared library for accessing pci devices
libpcre3 6.7+7.4-3 Perl 5 Compatible Regular Expression Library
libpopt0 1.10-3 lib for parsing cmdline parameters
libpq4 8.1.11-0etch1 PostgreSQL C client library
libreadline5 5.2-2 GNU readline and history libraries, run-time
libroken16-heimdal 0.7.2.dfsg.1-10 Libraries for Heimdal Kerberos
librpcsecgss3 0.14-2etch3 Allows secure rpc communication using the rpcsec_gss
protocol
libsasl2 2.1.22.dfsg1-8 Authentication abstraction library
libsasl2-2 2.1.22.dfsg1-8 Authentication abstraction library
libselinux1 1.32-3 SELinux shared libraries
libsemanage1 1.8-1 Shared libraries used by SELinux policy manipulation tools
libsensors3 2.10.1-3 Library to read temperature/voltage/fan sensors
libsepol1 1.14-2 Security Enhanced Linux policy library for changing policy
binaries
libsigc++-2.0-0c2a 2.0.17-2 Type-safe Signal Framework for C++ - runtime
libslang2 2.0.6-4 The S-Lang programming library - runtime version
libslp1 1.2.1-6.2 OpenSLP libraries
libsnmp-base 5.2.3-7etch2 NET SNMP (Simple Network Management Protocol) MIBs
and Docs
libsnmp9 5.2.3-7etch2 NET SNMP (Simple Network Management Protocol ) MIBs
and Docs
libss2 1.39+1.40-WIP-2006
.
11.14+dfsg-2etch1 command-line interface parsing library
libssl0.9.8 0.9.8c-4etch1 SSL shared libraries
libssp0 4.1.1-21 GCC stack smashing protection library
libstdc++6 4.1.1-21 The GNU Standard C++ Library v3
libstdc++6-4.1-dev 4.1.1-21 The GNU Standard C++ Library v3
(development files)
libsysfs2 2.1.0-1 Interface library to sysfs
libtasn1-3
0.3.6-2
Manage ASN.1 structures (runtime)
libtasn1-3-bin 0.3.6-2 Manage ASN.1 structures (binaries)
libtext-charwidth-perl 0.04-4 Get display widths of characters on the term
libtext-iconv-perl 1.4-3 Converts between character sets in Perl
libtext-wrapi18n-perl 0.06-5 Internationalized substitute of Text:Wrap
libusb-0.1-4 0.1.12-5 userspace USB programming library
libuuid1 1.39+1.40-WIP-2006
.
11.14+dfsg-2etch1 universally unique id library
libvolume-id0 0.105-4 libvolume_id shared library
libwrap0 7.6.dbs-13 Wietse Venema’s TCP wrappers library
linux-image-2.6-686 2.6.18+6etch2 Linux kernel 2.6 image on PPro/Celeron/PII/PIII/P4
linux-image-2.6.18-5-68
6
2.6.18.dfsg.1-17 Linux 2.6.18 image on PPro/Celeron/PII/PIII/P4

DA-681 Linux Introduction
1-7
Component Version Description
linux-kernel-headers 2.6.18-7 Linux Kernel Headers for development
locales 2.3.6.ds1-13etch5 GNU C Library: National Language (locale) data [support]
lockfile-progs 0.1.10 Programs for locking and unlocking files and mailboxes
login 4.0.18.1-7 System login tools
logrotate 3.7.1-3 Log rotation utility
lsb-base 3.1-23.2etch1 Linux Standard Base 3.1 init script function
make 3.81-2 The GNU version of the “make” utility.
makedev 2.3.1-83 Creates device files in /dev
manpages 2.39-1 Manual pages about using a GNU/Linux system
mawk 1.3.3-11 A pattern scanning and text processing language
mime-support 3.39-1 MIME files “mime.types” & “mailcap”, and support programs
minicom 2.2-5 Friendly menu driven serial communication program
mktemp 1.5-2 Makes unique filenames for temporary files
modconf 0.3.1 Device Driver Configuration
module-init-tools
3.3-pre4-2
Tools for managing Linux kernel modules
mount 2.12r-19etch1 Tools for mounting and manipulating filesystems
mysql-common 5.0.32-7etch8 Mysql database common files
(e.g. /etc/mysql my.cnf)
ncurses-base 5.5-5 Descriptions of common terminal types
ncurses-bin 5.5-5 Terminal-related programs and man pages
net-tools 1.60-17 The NET-3 networking toolkit
netbase 4.29 Basic TCP/IP networking system
nfs-common 1.0.10-6+etch.1 NFS support files common to client and server
openbsd-inetd 0.20050402-6 The OpenBSD Internet Superserver
openssh-client 4.3p2-9 Secure shell client, an rlogin/rsh/rcp replacement
openssh-server 4.3p2-9 Secure shell server, an rshd replacement
openssl 0.9.8c-4etch3 Secure Socket Layer (SSL) binary and related cryptographic
tools
openvpn 2.0.9-4etch1 Virtual Private Network daemon
passwd 4.0.18.1-7 Change and administer password and group data
pciutils 2.2.4~pre4-1 Linux PCI Utilities
perl 5.8.8-7etch3 Larry Wall's Practical Extraction and Report
perl-base 5.8.8-7etch3 The Pathologically Eclectic Rubbish Lister
perl-modules 5.8.8-7etch3 Core Perl modules
portmap
5-26
The RPC portmapper
ppp 2.4.4rel-8 Point-to-Point Protocol (PPP) daemon
pppconfig 2.3.15.etch1 A text menu based utility for configuring ppp
pppoe 3.8-1.1 PPP over Ethernet driver
procps 3.2.7-3 /proc file system utilities
proftpd 1.3.0-19etch1 Versatile, virtual-hosting FTP daemon
readline-common 5.2-2 GNU readline and history libraries, common files
sed 4.1.5-1 The GNU sed stream editor
snmp 5.2.3-7etch4 NET SNMP (Simple Network Management Protocol) Apps
snmpd 5.2.3-7etch4 NET SNMP (Simple Network Management Protocol) Agents
ssh 4.3p2-9etch3 Secure shell client and server (transitional package)
ssl-cert 1.0.14 Simple debconf wrapper for openssl
strace 4.5.14-2 A system call tracer
sysklogd 1.4.1-18 System Logging Daemon
sysv-rc 2.86.ds1-38+et System-V-like runlevel change mechanism
sysvinit 2.86.ds1-38+et System-V-like init utilities
sysvinit-utils 2.86.ds1-38+et System-V-like utilities
tar 1.16-2etch1 GNU tar

DA-681 Linux Introduction
1-8
Component Version Description
tcpd 7.6.dbs-13 Wietse Venema's TCP wrapper utilities
tcpdump 3.9.5-2etch1 A powerful tool for network monitoring and data acquisition
telnet 0.17-34 The telnet client
telnetd 0.17-34 The telnet server
tftpd 0.17-15 Trivial file transfer protocol server
time 1.7-21 The GNU time program for measuring cpu resource usage
traceroute 1.4a12-21 Traces the route taken by packets over a TCP
tzdata 2008e-1etch3 Time Zone and Daylight Saving Time Data
ucf 2.0020 Update Configuration File: preserves user changes to config
files.
udev 0.105-4 /dev/ and hotplug management daemon
update-inetd 4.27-0.5 inetd.conf updater
usbmount 0.0.14.1 Automatically mount and unmount USB mass storage
devices
usbutils
0.72-7
USB console utilities
util-linux 2.12r-19etch1 Miscellaneous system utilities
vim 7.0-122+1etch3 Vi IMproved - enhanced vi editor
vim-common 7.0-122+1etch3 Vi IMproved - Common files
vim-runtime 7.0-122+1etch3 Vi IMproved - Runtime files
vim-tiny 7.0-122+1etch3 Vi IMproved - enhanced vi editor - compact version
w3m 0.5.1-5.1 WWW browsable pager with excellent tables/frames support
wget 1.10.2-2 Retrieves files from the web
whiptail 0.52.2-10 Displays user-friendly dialog boxes from shell scripts
whois 4.7.20 The GNU whois client
zlib1g 1.2.3-13 Compression library - runtime

2
2. Software Configuration
In this chapter, we explain how to operate a DA-681-LX computer directly or from a PC near you. There are
three ways to connect to the DA-681-LX computer: through VGA monitor, by using Telnet over the network, or
by using an SSH console from a Windows or Linux machine. This chapter describes basic Linux operating
system configurations. The advanced network management and configuration will be described in the next
chapter “Managing Communications.”
The following topics are covered in this chapter:

Starting from a VGA Console

Connecting from a Telnet Console

Connecting from an SSH Console
Windows Users
Linux Users

Adjusting the System Time
Setting the Time Manually
NTP Client
Updating the Time Automatically

Enabling and Disabling Daemons

Setting the Run-Level

Cron—Daemon for Executing Scheduled Commands

Inserting a SATA Hard Drive into the Computer

Inserting a USB Storage Device into the Computer

Inserting a CompactFlash Card into the Computer

Checking the Linux Version

APT—Installing and Removing Packages

WDT (Watchdog Timer)

DA-681 Linux Software Configuration
2-2
Starting from a VGA Console
Connect the display monitor to the DA-681-LX VGA connector, and then power it up by connecting it to the
power adaptor. It takes about 30 to 60 seconds for the system to boot up. Once the system is ready, a login
screen will appear on your monitor.
To log in, type the login name and password as requested. The default values are both root.
Login: root
Password: root
login as: root
[email protected]'s password:
Last login: Mon Jan 22 19:02:16 2007 from 192.168.3.120
#### #### ###### ####### ###### ##
### #### ### ### #### #### ##
### ### ### ### ### ## ###
### #### ### ## ### # ####
#### # ## ### ### ### ## ## ##
## ## # ## ### ## #### # ##
## ### ## ## ## ## #### # ###
## ## # ## ## ## ### ########
## ## # ## ### ### ##### # ##
## ### ## ### ### ## ### # ###
## ### ## ## ## ## ### ## ##
## ### ## ## ## # ### # ##
###### # ###### ######## ####### ########### ######
For further information check:
http://www.moxa.com/
Mount user file system.
Moxa:~#
Connecting from a Telnet Console
The DA-681-LX computer comes with 6 10/100 Mbps Ethernet ports named LAN1 to LAN6. The default IP
addresses and netmasks of the network interfaces are as follows:
Default IP Address Netmask
LAN 1 192.168.3.127 255.255.255.0
LAN 2 192.168.4.127 255.255.255.0
LAN 3 192.168.5.127 255.255.255.0
LAN 4
192.168.6.127
255.255.255.0
LAN 5 192.168.5.127 255.255.255.0
LAN 6 192.168.6.127 255.255.255.0
Before using the Telnet client, you should change the IP address of your development workstation so that the
network ports are on the same subnet as the IP address for the LAN port that you connect to. For example, if
you connect to LAN 1, you could set your PC’s IP address to 192.168.3.126, and the netmask to 255.255.255.0.
If you connect to LAN 2, you can set your PC’s IP address to 192.168.4.126, and the netmask to
255.255.255.0.

DA-681 Linux Software Configuration
2-3
Use a cross-over Ethernet cable to connect your development workstation directly to the target computer, or
use a straight-through Ethernet cable to connect the computer to a LAN hub or switch. Next, use a Telnet client
on your development workstation to connect to the target computer. After a connection has been established,
type the login name and password as requested to log on to the computer. The default values are both root.
Login: root
Password: root
ATTENTION
If you cannot get connected on the first try, re
-
check the IP address and netmask settings, and then unplug and
re
-plug the DA-681-LX’s power cord.
Connecting from an SSH Console
The DA-681-LX computer supports an SSH Console to offer users with better security over the network
compared to Telnet.

DA-681 Linux Software Configuration
2-4
Windows Users
Click on the link http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html to
download PuTTY (free software) to set up an SSH console for the DA-681-LX in a Windows environment. The
following screen shows an example of the configuration that is required.
Linux Users
From a Linux machine, use the ssh command to access the DA-681-I-LX’s console utility via SSH.
#ssh 192.168.3.127
Select yes to open the connection.
[root@bee_notebook root]# ssh 192.168.3.127
The authenticity of host ‘192.168.3.127 (192.168.3.127)’ can’t be established.
RSA key fingerprint is 8b:ee:ff:84:41:25:fc:cd:2a:f2:92:8f:cb:1f:6b:2f.
Are you sure you want to continue connection (yes/no)? yes_
Adjusting the System Time
The DA-681-LX has two time settings. One is the system time, and the other is provided by an RTC (Real Time
Clock) built into the DA-681- LX’s hardware.
Setting the Time Manually
Use the date command to query the current system time or set a new system time. Use hwclock to query the
current RTC time or set a new RTC time.
Use the following command to set the system time.

DA-681 Linux Software Configuration
2-5
# date MMDDhhmmYYYY
MM: Month
DD: Date
hhmm: Hour and Minute
YYYY: Year
Use the following command to write the current system time to the RTC.
# hwclock –w
Moxa:~# date
Fri Jun 23 23:30:31 CST 2000
Moxa:~# hwclock
Fri Jun 23 23:30:35 2000 -0.557748 seconds
Moxa:~# date 120910002004
Thu Dec 9 10:00:00 CST 2004
Moxa:~# hwclock –w
Moxa:~# date ; hwclock
Thu Dec 9 10:01:07 CST 2004
Thu Dec 9 10:01:08 2004 -0.933547 seconds
Moxa:~#
NTP Client
The DA-681-LX has a built-in NTP (Network Time Protocol) client that is used to initialize a time request to a
remote NTP server. Use ntpdate to update the system time.
#ntpdate time.stdtime.gov.tw
#hwclock –w
Visit http://www.ntp.org for more information about NTP and NTP server addresses.
Moxa:~# date ; hwclock
Sat Jan 1 00:00:36 CST 2000
Sat Jan 1 00:00:37 2000 -0.772941 seconds
Moxa:~#
Moxa:~# ntpdate time.stdtime.gov.tw
9 Dec 10:58:53 ntpdate[207]: step time server 220.130.158.52 offset 155905087.9
84256 sec
Moxa:~#
Moxa:~# hwclock -w
Moxa:~# date ; hwclock
Thu Dec 9 10:59:11 CST 2004
Thu Dec 9 10:59:12 2004 -0.844076 seconds
Moxa:~#
ATTENTION
Before using the NTP client utility, check your IP address and network settings to make sure an Internet
connection is available.

DA-681 Linux Software Configuration
2-6
Updating the Time Automatically
This section describes how to use a shell script to update the time automatically.
Example shell script for updating the system time periodically
#!/bin/sh
ntpdate time.nist.gov
# You can use the time server’s ip address or domain
# name directly. If you use domain name, you must
# enable the domain client on the system by updating
# /etc/resolv.conf file.
hwclock –w
sleep 100
# Updates every 100 seconds. The min. time is 100 seconds.
# Change 100 to a larger number to update RTC less often.
Save the shell script using any file name. For example, fixtime.
How to run the shell script automatically when the kernel boots up
Because the root file system is mounted in Read-only mode, we need to re-mount it using writable permission.
# mount -o remount,rw /dev/hda1 /
Copy the example shell script fixtime to directory /etc/init.d, and then use chmod 755 fixtime to change
the shell script mode.
# chmod 755 fixtime
Next, use vi editor to edit the file /etc/inittab.
# vi /etc/inittab
Add the following line to the bottom of the file:
ntp : 2345 : respawn : /etc/init.d/fixtime
After you finish writing or modifying the code, remember to execute “umount /” to change the root directory
back to Read-only mode.
# umount /
Use the command #init q to re-initialize the kernel.
# init q

DA-681 Linux Software Configuration
2-7
Enabling and Disabling Daemons
The following daemons are enabled when the DA-681-LX boots up for the first time.
•snmpd SNMP Agent Daemon
•telnetdTelnet Server/Client Daemon
•inetd Internet Daemons
•ftpd FTP Server/Client Daemon
•sshd Secure Shell Server Daemon
•httpd Apache WWW Server Daemon
Type the command ps –ef to list all processes currently running.
Moxa:~# ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 00 Feb18 ? 00:00:01 init [2]
root 2 1 0 Feb18 ? 00:00:00 [migration/0]
root 3 1 0 Feb18 ? 00:00:00 [ksoftirqd_0]
root 4 1 0 Feb18 ? 00:00:00 [events/0]
root 5 1 0 Feb18 ? 00:00:00 [khelper]
root 6 1 0 Feb18 ? 00:00:00 [kthread]
root 9 6 0 Feb18 ? 00:00:00 [kblockd/0]
root 10 60 Feb18 ? 00:00:00 [kacpid]
root 107 6 0 Feb18 ? 00:00:00 [kseriod]
root 143 6 0 Feb18 ? 00:00:00 [pdflush]
root 144 6 0 Feb18 ? 00:00:00 [pdflush]
root 145 6 0 Feb18 ? 00:00:00 [kswapd0]
root 146 6 0 Feb18 ? 00:00:00 [aio/01]
root 622 6 0 Feb18 ? 00:00:00 [khubd]
root 763 6 0 Feb18 ? 00:00:00 [scsi_eh_0]
root 765 6 0 Feb18 ? 00:00:00 [usb-storage]
root 1119 1 0 Feb18 ? 00:00:00 udevd --daemon
root 1527 6 0 Feb18 ? 00:00:00 [kpsmoused]
root 1754 6 0 Feb18 ? 00:00:00 [kmirrord]
daemon 2094 1 0 Feb18 ? 00:00:00 /sbin/portmap
root 2311 1 0 Feb18 ? 00:00:00 /usr/sbin/acpid
-c /etc/acpi/evemts –s /var/run/acpid.socket
root 2318 1 0 Feb18 ? 00:00:00 /usr/sbin/inetd
To run a private daemon, you can edit the file rc.local as follows:
1. Because the root file system is mounted in Read-only mode, you need to re-mount it with write permission.
Moxa:~# mount -o remount,rw /dev/hda1 /
2. Type cd /etc/ to change directories.
Moxa:~# cd /etc/
3. Type vi rc.local to edit the configuration file with vi editor.
Moxa:/etc/# vi rc.local
4. Next, add the application daemon that you want to run. We use the example program tcps2-release to
illustrate, and configure it to run in the background.

DA-681 Linux Software Configuration
2-8
# !/bin/sh
# Add the daemonyou want to run daemon
/root/tcps2-release &
5. After you finish writing or modifying the code, remember to execute “umount /” to change the root directory
back to Read-only mode.
Moxa:~# umount /
6. You should be able to find the enabled daemon after you reboot the system.
Moxa:~# ps -ef
UID PID PPID C STIME TTY TIME CMD
root 1 0 0 Feb18 ? 00:00:01 init [2]
root 2 1 0 Feb18 ? 00:00:00 [migration/0]
root 3 1 0 Feb18 ? 00:00:00 [ksoftirqd_0]
root 4 1 0 Feb18 ? 00:00:00 [events/0]
root 5 1 0 Feb18 ? 00:00:00 [khelper]
root 6 1 0 Feb18 ? 00:00:00 [kthread]
root 9 6 0 Feb18 ? 00:00:00 [kblockd/0]
root 10 6 0 Feb18 ? 00:00:00 [kacpid]
root 107 6 0 Feb18 ? 00:00:00 [kseriod]
root 143 6 0 Feb18 ? 00:00:00 [pdflush]
root 144 6 0 Feb18 ? 00:00:00 [pdflush]
root 145 6 0 Feb18 ? 00:00:00 [kswapd0]
root 146 6 0 Feb18 ? 00:00:00 [aio/01]
root 622 6 0 Feb18 ? 00:00:00 [khubd]
root 763 6 0 Feb18 ? 00:00:00 [scsi_eh_0]
root 765 6 0 Feb18 ? 00:00:00 [usb-storage]
root 1119 1 0 Feb18 ? 00:00:00 udevd --daemon
root 1527 6 0 Feb18 ? 00:00:00 [kpsmoused]
root 1754 6 0 Feb18 ? 00:00:00 [kmirrord]
daemon 2094 1 0 Feb18 ? 00:00:00 /sbin/portmap
root 2311 1 0 Feb18 ? 00:00:00 /usr/sbin/acpid
-c /etc/acpi/evemts –s /var/run/acpid.socket
root 2318 1 0 Feb18 ? 00:00:00 /usr/sbin/inetd
root 2452 1 0 Feb18 ? 00:00:00 /root/tcps2-release
Setting the Run-Level
To set the Linux run-level and execution priority of a program, use the following command (because the root
file system is mounted in Read-only mode, we need to re-mount it with write permission).
Moxa:~# mount -o remount,rw /dev/hda1 /
Edit a shell script to execute /root/tcps2-release and save to tcps2 as an example. This program can be
found in Example Directory in CD-ROM.
#cd /etc/rc2.d
#ln –s /etc/root/tcps2 S60tcps2
or
#ln –s /etc/root/tcps2 k30tcps2

DA-681 Linux Software Configuration
2-9
MOXA:~# cd /etc/rc2.d
MOXA:/etc/rc2.d#
MOXA:/etc/rc2.d# ls
S19nfs-common S25nfs-user-server S99showreadyled
S20snmpd S55ssh
S24pcmcia S99rmnologin
MOXA:/etc/rc2.d#
MOXA:/etc/rc2.d# ln –s /root/tcps2-release S60tcps2
MOXA:/etc/rc2.d# ls
S19nfs-common S25nfs-user-server S99rmnologin
S20snmpd S55ssh S99showreadyled
S24pcmcia S60tcps2
MOXA:/etc/rc2.d#
The command SxxRUNFILE has the following meaning:
S: Start the run file while Linux boots up.
xx: A number between 00-99. The smaller number has a higher priority.
RUNFILE: The script file name
The command KxxRUNFILE has the following meaning:
K: Start the run file while Linux shuts down or halts.
xx: A number between 00-99. The smaller number has a higher priority.
RUNFILE: The script file name
To remove the daemon, remove the run file from /etc/rc2.d by using the following command:
# rm –f /etc/rc2.d/S60tcps2
After you finish writing or modifying the code, remember to execute “umount /” to change the root directory
back to Read-only mode.
MOXA:~# umount /
Cron—Daemon for Executing Scheduled
Commands
The Cron daemon will search /etc/crontab for crontab files, which are named after accounts
in /etc/passwd.
Cron wakes up every minute and checks each command to see if it should be run in that minute. When
executing commands, output is mailed to the owner of the crontab (or to the user named in the MAILTO
environment variable in the crontab, if such a user exists).
Modify the file /etc/crontab to set up your scheduled applications. Crontab files have the following format:
mm h dom mon dow user command
minute hour date month week user command
0-59 0-23 1-31 1-12 0-6 (0 is Sunday)
For example, if you want to launch a program at 8:00 every day
#minute hour date month week user command
* 8 * * * root /path/to/your/program
The following example demonstrates how to use Cron to update the system time and RTC time every day at
8:00.