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Month's Topics: |
 Hot
News
Starting with this issue, we will introduce Moxa Connection
readers to selected topics from our Serial-to-Ethernet
Guidebook. Each Moxa Connection issue will highlight
a different topic of interest. For more information
about the guidebook, please refer to www.moxa.com/s2e,
or contact us directly by e-mail at s2e@moxa.com.tw.
Monthly Features
In this paper, we discuss some basic characteristics
of Ethernet, how it applies to the industrial setting,
and then consider the particular role that Ethernet
switches play in helping ensure deterministic data transmission
over a network.
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A Profile of the RS–485 Standard
In order to assist customers with more complicated
applications, we will be introducing several topics
related to RS-232/422/485 serial communications. We
hope that this new Moxa Connection feature will make
it easier for readers to build up efficient and reliable
data communications systems. More...
Important
Marketing Issues
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Marketing Events
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Moxa achieves an outstanding
sales performance in the Korean market in 2001,
with more than 100% growth.
Even though the economic situation for most
countries in Asia was harsh, and there was a
major slump in 2001, More...
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A new era is under way
As 2002 gets under way, Moxa Germany is ready
with new ideas and new strategies designed to
help our distributors build up an even stronger
sales performance. More...
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Visit our booth at LINUX
EXPO 2002 in Paris
Good news for our French customers! MOXA and
French partner ADM21 will man a booth together
at LINUX EXPO / LINUX WORLD PARIS 2002. More...
Important
Product Issues
MOXA Announces an Economical Sync I/O Board for
PCI
We have expanded our cost-effective C101 SuperSync
Board family by introducing a PCI solution. More...
Timely
Product Applications
Remotely Reboot and Control Campus Network Equipment
using MOXA NPower Commander
Use MOXA NPower Commander to build up an easy-to-implement
control system that uses an existing phone line at the
remote site. More...
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Special Educational Supplement
The Serial-to-Ethernet Guidebook: Solutions Utilizing
Serial Device Server Technology
January's topic: Serial to Ethernet solutions:
Pair Connection for NPort Express
Pair Connection Mode involves using two or more appropriately
configured serial device servers that work in unison to
form a serial tunnel. The serial tunnel operates by encapsulating
serial data in a TCP packet, which is then transported
over an Ethernet network.
This operation mode is used with applications that do
not use a network-able device, but instead use either
DOS-based PCs or specialized computers such as hand-held
PDAs, neither of which can be directly connected to an
Ethernet. Pair Connection Mode allows these devices to
be easily connected to an Ethernet, and gives them the
capability to communicate with serial devices such as
the PLC shown in the above figure.
Another benefit of Pair Connection Mode is that it can
cope with any type of proprietary protocol, such as Siemens'
or Allen-Bradley's PLC protocols. In fact, many industrial
environments use devices that are designed to communicate
over serial connections, but by using some type of proprietary
protocol maintained and distributed by the device manufacturer.
What pair connection mode does is simply encapsulate the
data into TCP packets, and then send the data over an
Ethernet connection. The device server on the receiving
end strips away the TCP headers, and then presents the
original data to the connected serial device.
White Paper: “Why Use an Industrial
Ethernet Switch”
In this paper, we discuss some basic characteristics
of Ethernet, how it applies to the industrial setting,
and then consider the particular role that Ethernet switches
play in helping ensure deterministic data transmission
over a network.
by Vincent Liu, Industrial Ethernet
Switch Sales and Marketing Manager
A Profile of the RS-485 Standard
 The
RS-485 "Multidrop network" standard has been
used in many different applications since it was first
released. The full name of the RS-485 standard is TIA/EIA-485-A,
with the latest version issued on March 3, 1998 by the
Telecommunications Industry Association (TIA), in association
with the Electronic Industries Alliance (EIA).
Note that TIA/EIA-485-A, or RS-485, is a half-duplex
multidrop network, which means that multiple transmitters
and receivers may reside on the cable, but only one transmitter
may be active at any given time. Data is transmitted differentially
on a "twisted pair" of wires. Differential signals
are used since they can provide high noise immunity and
long distance transmission capability. The two transmission
lines of the twisted pair are labeled A and B, although
many manufacturers label their wires "-" and
"+", respectively. Figure 1 shows how TIA/EIA-485-A
defines Voa, Vob, and Vo. The driver generates complementary
voltages on wires A and B. When Voa is low, Vob is high,
and when Voa is high, Vob is low; Vo depicts the differential
Voltage between wires A and B.
Receivers are designed to be sensitive to a 200 mV difference.
A voltage difference between A and B that is less than
200 mV is indeterminate.
RS-485 supports networks up to 5000 feet in length, with
transmission rate up to 10 Mbps. The rate of data transmission
is traded off against cable length, cable type, termination,
driver and receiver used, EMI coupler, and even physical
topology.
The TIA/EIA-485-A specification defines a UL (Unit Load),
which declares that an RS-485 driver must be able to drive
32 ULs. This means that an RS-485 network supports 32
nodes, when each node bears a unit load on the line. Some
manufacturers now sell 1/4 UL transceivers (DS1487) and
even 1/8 UL parts (MAX1482). Assuming each node presents
1/8 UL to the transmission line, an RS-485 network could
support up to 32 x 8 = 256 nodes.
In theory, by using repeaters, multiple networks can
be chained together with an unlimited number of nodes.
The propagation delays, however, become significant for
large networks with multiple repeaters and long transmission
lines, and consequently the data rate may become unacceptably
slow.
The TIA/EIA-485-A specification does not say anything
about the communications protocol used on the network.
The software engineer has the liberty to implement whichever
type of network protocol (Modbus, Data Highway, Interbus,
etc.) is most applicable to the current project.
We hope that this overview gives readers a good basic
understanding of RS-485. In upcoming issues of Moxa Connection,
we'll take a closer look at the following topics:
Grounding
Topology
Termination
Isolation & Surge Protection
by Daniel Jan, Multiport Asynchronous
Board Product Manager
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Important
Marketing Issues |
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Marketing Events
Moxa achieves
an outstanding sales performance in the Korean market
in 2001, with more than 100% growth.
Even though the economic situation for most countries
in Asia was harsh, and there was a major slump in 2001,
Moxa was still able to achieve an outstanding sales performance
in the Korean market, with more than 100% growth. Moxa's
two Korean distributors, DAESE and YOI, put forward a
great effort at providing Moxa's cost-effective solutions
to satisfy their clients' needs.
In 2001, we also held our first ever seminar in Korea.
It was a great success, providing us with a good opportunity
to catch the eye and hear the voice of our target customers.
Moxa will continue working the market more intensely so
that we may help all of our customers get the most benefit
out of Moxa's solutions.
Our goal is to get 50% additional growth in 2002, and
we expect to meet this challenge by continually launching
new products, and providing customers with the most up-to-date
technologies and solutions. Let's welcome this sure to
be prosperous Year of the Horse together, and work throughout
the year to ensure great sales figures, and great success!
by Richard Chuang, Sales Manager for Asia
A new era is
under way
As 2002 gets under way, Moxa Germany is ready with new
ideas and new strategies designed to help our distributors
build up an even stronger sales performance. Many special
events are in the works to enhance sales capability, and
to enlarge Moxa's German market share. In addition to
Hannover C'eBIT and Messe, coming this March and April,
Moxa Germany will hold several seminars, and is scheduled
to conduct eight System Solution Training Courses in May
and June.
Moxa Germany will join our distributors in holding several
seminars to promote new Moxa products, such as NPort Express
and Moxa NSwitch. And then in May and June we will hold
a series of System Solution Training Courses for System
Integrators doing business in the local German market.
By offering these training courses, Moxa will introduce
new products to system integrators, and present system
applications and success stories to customers, giving
them the opportunity to learn about the benefits and advantages
of how Moxa products can be used in industry.
There is currently a big need for serial-to-Ethernet
products, and Moxa Technologies, as a leading provider
of top quality communications products, responded to this
need by releasing the successful NPort Express Family
(this includes NPort Express Module, a credit card sized
embedded module), which allows the industrial automation
industry to keep pace with the "Everything is networked"
trend. By using products from the NPort Express Family,
serial devices can be valued-added in no time, with the
value of existing equipment easily extended into the next
generation. Moxa's System Solution Training Courses, which
are scheduled for later this year, will be used to fulfill
the needs of the market place, and help to ensure that
System Integrators from all industrial fields fully understand
how serial-to-Ethernet provides the ultimate solution
for Internet information access.
We are confident that our efforts will pay off, and that
the events we have planned for the coming year will help
to ensure customers that Moxa is committed to providing
the most cost-effective solutions and top quality industrial
communications products.
by Eric Chen, Sales Manager for Germany
Visit our
booth at LINUX EXPO 2002 in Paris
Good news for our French customers!
MOXA and French partner ADM21 will man a booth together
at LINUX EXPO / LINUX WORLD PARIS 2002. The exhibition
will be held at CNIT - Paris La Defense, and will last
for 3 days, from Jan 30th to Feb 1st. Please visit us
at booth No. B15.
We will focus on the topic "Explore the Power of
Serial-to-Ethernet Connectivity" at this LINUX EXPO.
You will be able to see all of MOXA's Serial-to-Ethernet
products, and get a copy of our very useful guidebook
on Serial-to-Ethernet technology and applications. The
guidebook highlights typical solutions that utilize serial
device server technology.
by Peter Feng, Sales Manager for Europe
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MOXA Announces an Economical Sync I/O Board for PCI
We have expanded our cost-effective C101 SuperSync Board
family by introducing a PCI solution. The 32-bit MOXA
C101/PCI SuperSync Board features simultaneous analog
input and output, an Hitachi HD64570 SCA (Serial Communication
Adapter) chip, and a built-in DMA (Direct Memory Access)
Controller to boost system speed up to 4 Mbps. In addition,
this sync board supports Sync API, such as C/C++, Visual
Basic, Delphi (Windows NT), C (DOS), and DLL (Windows
3.x), making it an ideal yet low cost synchronous communications
hardware solution for software developers.
by Josephine Huang, Sync I/O Board Product
Manager
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Timely Product pplications |
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Remotely Reboot and Control Campus Network Equipment using
MOXA NPower Commander
The Challenge
Off-duty campus administrative staff are unable to quickly
reboot or reset network equipment that has locked up in
the middle of the night.
The Solution
Use MOXA NPower Commander to build up an easy-to-implement
control system that uses an existing phone line at the
remote site. You will be able to reboot campus network
equipment that has "locked-up," and quickly
restore it to normal operation, all from a remote, centralized
control center.
MOXA NPower Commander is being used with great success
as part of a control system at one of Taiwan's universities.
"We purchased big brand internetworking equipment
for our campus, but still encountered downtime caused
by OS crashes and system lock-up. However, we found that
80% of these locked-up network equipment problems could
be solved with a simple reboot operation, so we started
looking for a remote reboot or power control device to
take care of the campus's distributed network equipment,"
remarked a system administrator at the University.
Unlike many competitor's products, MOXA NPower Commander
provides a telephone interface for dependable backup,
greatly assisting the system administrator in getting
the job done when the network is down. In addition, MOXA
NPower Commander's API helps speed up development time,
and makes it much easier to build up different types of
automation applications.
Click here to learn more about this great product.
by Josephine Huang, NPower Commander Product
Manager
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March
13 – 20, 2002
Hannover, Germany, Hall 15,
Booth No. G52/14 |
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We
hope Moxa Connection's fresh look and new style brings
you a new and valuable outlook on our company and
products. We look forward to hearing any comments
you might have about the new format.
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