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What is IEEE 1394?
IEEE 1394 is an industry standard for a
scalable, flexible, easy to use, low-cost
digital interface that integrates the
worlds of consumer electronics and
personal computers. It was first conceived
by Apple Computer and then developed by
the 1394 Working Group within the
Institute of Electrical and Electronics
Engineers (IEEE). The IEEE 1394 standard
defines its interface as:
Digital. 1394 does not require
the conversion of digital data into
analog. That means better signal
integrity.
Physically small. 1394 provides a
thin serial cable which replaces today's
bulky and expensive interfaces.
Easy to use. 1394 eliminates the
need to load software or perform
complicated set-ups.
Hot pluggable. 1394 enables
devices to be added and removed while
equipment is turned on and does not
require computers to be "rebooted."
Scalable. 1394 supports multiple
speeds including devices operating at 100,
200 and 400 Megabits per second on a
single continuous cable or "bus."
Flexible. 1394 supports freeform
daisy chaining and branching, which
reduces cabling complexity and supports
"peer-to-peer" connections the ability
for consumer electronic devices to be
connected without the need for a computer.
Fast. 1394 supports guaranteed
delivery of time critical data which
enables high-quality audio and video
applications while reducing the cost of
the interface.
Does 1394 have a formal name?
The name FireWire, which was coined by
Apple, is still used by them and a few
other manufacturers. Others have adopted
the name i.LINK, which is trademarked by
Sony Corporation. The name 1394 actually
comes from the IEEE 1394 specification
which defines the technical
characteristics of the interface.
Why another interface?
Several key trends have led to the
need for a new digital interface:
Consumer electronics and computers are
"converging."
There is a desire to keep data in the
digital domain for as long as possible, as
a means to reduce system cost, complexity
and to improve signal integrity.
With the emergence of multimedia, more
and more data is video and audio. The
ability to work with this time-sensitive
data is growing in importance.
Miniaturization is continuing. Small
products are favored for portability,
convenience and material resource usage.
The predominance of PCs in the home has
led to consumers purchasing computers the
way they choose consumer electronics.
Their criteria are: reliability,
convenience and simplicity.
The need and desire for peer-to-peer
computing is growing. For example, this
would include the ability to connect a
digital camera directly to a printer to
print photographs. 1394 does not require
the use of a computer.
What will 1394 do?
1394 is already the computer
attachment for digital cameras and digital
video applications. IEEE 1394 has been
accepted as the standard digital interface
by the Digital VCR Conference (DVC), and
the European Digital Video Broadcasters (DVB)
have endorsed IEEE 1394 as their digital
television interface as well. The VESA
(Video Experts Standards Association) is
evaluating IEEE 1394 for digital home
networks. But this is just the beginning.
Many new non-video products are already
1394-enabled including PCs, digital still
cameras, printers, network hubs and
storage devices.
What kind of products can talk to each
other over 1394?
1394 is for connecting digital
electronic devices. It will not work with
your existing analog equipment (for
example, your old VHS VCR, Hi8 camcorder
or TV). Rather, digital devices include DV
camcorders and VCRs, digital still
cameras, digital set-top boxes, digital TV
sets and many computer peripheral devices
that have a 1394 connector.
What if my computer does not already
have a 1394 connector?
No problem. Several companies offer
relatively inexpensive 1394 adapters, also
referred to as 1394 "add-on" or "adapter"
cards. These cards are actually printed
circuit boards that can be easily inserted
into a slot (usually a PCI slot) inside
your computer. The cards include one or
more 1394 connectors and, once inserted,
enable your computer to communicate with
1394-enabled consumer electronic and
peripheral devices.
Can I connect and disconnect 1394
devices without turning the power off?
Yes. 1394 is "hot pluggable." That
means when you plug in a new device, the
1394 "bus" automatically recognizes it.
Similarly, when a device is disconnected,
1394 automatically reconfigures itself. In
fact, the standard 1394 cable provides up
to 1.5 amps of DC power to keep remote
devices "aware," even when they are turned
off.
Do I need a computer to make 1394 work?
No. You do not need a computer to take
advantage of 1394. A 1394-enabled VCR, for
example, can be connected directly to a
1394-enabled camcorder, TV set, stereo
receiver, amplifier or other home theater
component without the need for a computer.
Why is 1394 good for video editing?
In the world of video editing,
1394-enabled cameras remove the need for
costly analog-to-digital converters and
frame buffers, otherwise known as "video
capture" cards. 1394 also improves upon
existing interfaces such as SCSI,
traditionally used for the storage of
digital video. 1394 provides higher speed,
lower cost, and is more user-friendly than
existing video interfaces.
What about computer peripherals, like
my printer?
1394 has the bandwidth capacity to
replace and consolidate most other
peripheral connection/communication
methods in use today. Hot plugging, power
sourcing and dynamic reconfiguration make
1394 a user-friendly alternative to
today's interconnects. These features
allow "plugging in" of computer
peripherals as easily as plugging in a
home appliance. In fact, manufacturers of
SCSI products, such as scanners, CD-ROMs,
disk drives and printers are already
evaluating when they will move to 1394.
What is the difference between 1394 and
Universal Serial Bus (USB)?
Almost everyone who works with these
technologies considers 1394 a complement
to USB, since it offers much higher speeds
(up to 1.2 Gigabit) and was designed
primarily with video/audio/data transfer
in mind. USB is ideal for, and was
designed for, computer peripherals at
speeds in the neighborhood of
480
Mbps (in
fact, USB requires a computer). 1394, on
the other hand, has a different mission:
to be an interface for both consumer
electronic devices and computers. Many new
PCs now include ports for both of these
standards.
 What is FireWireฎ?
FireWire is an Apple trademark for the
IEEE 1394 standard.
 What is i.LINKฎ?
i.LINK is a Sony trademark for the
IEEE 1394 standard.
What is the future of 1394?
1394 has the potential to transform
the consumer electronics and computer
industries by making a vast array of new
applications possible. Once an electronic
device becomes 1394-enabled, it can share
data with other devices and be controlled
by a computer. If the computer is
connected to the Internet, that control is
extended to locations worldwide.
Let's say you forgot to program your VCR
to record a show while you're at work. No
problem. Because your VCR is digital and
connected to your home network through its
1394 jack, you can access it over the
Internet and program it from your PC at
work. In fact, 1394 will make it possible
to do things like backup your computer
files to the digital tape in your VCR.
Hey, what's going on at home? Here's
another one. Your relatively inexpensive
1394-enabled home-security system includes
miniature video cameras and audio
surveillance equipment. So you can see and
hear exactly what's going on in and around
your house from your home computer, your
digital TV monitors, your office computer,
your wireless handheld computer - well,
just about anywhere.
And while you're out to dinner, it will
also provide a great baby monitor to drop
in on the sitter and kids right from your
table (using your wireless palm PC).
Capture the special moments (and scrap the
rest). Everyone wants to capture those
special, cherished moments in their lives
so they can recall them later. But not
everyone wants to pay for the high cost of
film and development. Especially when out
of 20 or 32 exposures, you might get a
dozen really good pictures.
Todays high-quality 1394-enabled printers,
let you print only the pictures you want
to keep. And there's no waiting, no film
to buy and no development cost. Better
yet, you can print from any 1394-enabled
still camera or video camera.
Keeping up around the house. It's
conceivable that someday, a 1394 network
in your home will let you run just about
everything by remote. Did it turn out to
be a hot day? Just turn on your home's
central air system from your car before
you arrive and keep your cool. It's a
stretch, but someday you might even be
able to tell if the clothes in your drier
are dry and start the machine again from
your palm-top, your dash-top or the
computer.
Why was 1394 created?
1394 was designed to be a global
interconnect, eliminating the need for
many different input/output connectors.
The resulting port integration and
consolidation of circuit board space
results in an overall reduction in product
cost and complexity. The 1394 bus is a
versatile, high-speed and inexpensive
method of interconnecting a variety of
consumer electronics devices and personal
computers, while eliminating the
frustrating tangle of cables most users
encounter today.
How many devices can be connected
with 1394?
With 1394 you can connect up to 63
devices together. When 1394.1 bus bridges
become available, it will be possible to
connect over 60,000 devices using 1394.
Digital camcorders, surround sound
processors, scanners, printers, hard disk
audio recorders, videoconferencing cameras
and disk drives all share a common bus
connection, not only to an optional host
computer, but to each other as well.
Because of this, 1394 is a prime candidate
for the "Home Network" standard initiated
by VESA (Video Electronic Standards
Association) and other industry
associations.
How fast is 1394?
The 1394 standard defines three
signaling rates which, in precise terms,
are: 98.304, 196.608 and 393.216 Mbits/s
(megabits per second). These rates are
referred to in the 1394 standard as S100,
S200 and S400. There are efforts underway
to expand the standard to include 800 and
1,200 Mbits/s speeds. You can mix and
match devices of different speeds on the
same bus. Using "isochronous" data
transmission, even the S100 implementation
supports two simultaneous channels of
30fps (frames per second)
broadcast-quality video along with stereo
audio.
What software do I need?
All modern personal computer operating
systems already support 1394, including
Windows 98, Windows 2000, Mac OS 8.6, and
Mac OS 9.0.
Can I connect and disconnect devices
without turning the power off?
Yes. 1394 is defined as "hot
pluggable." That means when you add a new
device, the 1394 bus automatically
recognizes it. Similarly, when a device is
disconnected, the bus automatically
reconfigures itself. The standard 1394
cable provides up to 1.5 amps of DC power
to keep remote devices "aware," even when
they are powered down.
Do I need a computer on the 1394 bus to
make it work?
No. You do not need a computer to take
advantage of 1394. A VCR, for example, can
act as a 1394 bus controller for
camcorders, TV sets, stereo receivers,
amplifiers and other home theater
components.
How does 1394 compare to SCSI?
The SCSI bus requires that devices be
serially daisy-chained together, with each
device having a non-conflicting,
pre-assigned address and that the final
SCSI device be terminated. There is a
limit of seven devices on a SCSI chain. In
contrast, 1394 devices can be connected in
multiple configurations. These can include
a star or tree pattern with its own daisy
chain branches. Device terminators are not
required. And 1394 addressing, unlike
SCSI, is done dynamically; there is no
need for address pre-assignment. Plus,
1394 allows up to 1,023 buses to be
bridged together.
How does 1394 compare to Ethernet?
1394 multiplexes (combines) a variety
of different types of digital signals,
including video, audio, MIDI and device
control commands, on two twisted-pair
conductors (similar to that of 10base-T
Ethernet). This ability to easily
multiplex or combine different signal
types distinguishes 1394 from other
systems which transmit only a single
signal type.
Ethernet, for example, is typically used
in data networks and requires special
protocols (presently implemented only in
proprietary multimedia networking systems)
to transmit real-time, high-quality audio
and video.
In comparison, 1394 is much more flexible
in its accommodation of different data
types and topologies than Ethernet and
other alternative networking systems. 1394
uses a "fairness" arbitration approach to
assure that all devices that have
information to transmit get a chance to
use the bus. 1394 protocols also include
device-specific commands to start and stop
camcorders, VCRs and other tasks. Standard
Ethernet does not provide these important
features.
What does a 1394 cable look like?
1394 interconnections are usually made
with a 6-conductor cable that contains two
separately shielded "twisted" pairs for
transmitting data, plus two power
conductors and an overall external shield.
The two twisted pairs create a
transmit/receive connection. The power
conductors (8 to 30VDC, 1.5A) supply power
to some devices.
Some devices, such as most digital
camcorders, use a smaller 4-pin connector
to save space. You can buy a 1394 cable
with the 6-pin connector on one end, and
the 4-pin connector on the other end in
order to connect these devices.
Why do most DV camcorders have 4-pin
1394 connectors?
Sony camcorders have only a single
4-pin 1394 connector. It is smaller than
the standard 1394 connector and has only
the data signaling pairs (no power
conductors). The 4-pin 1394 connector is a
part of the 1394 standard intended
primarily for battery-powered devices.
What about the 4.5-meter cable length
limitation?
1394 cables are limited to 4.5 meters
between devices before signal distortion
begins to occur. The use of 1394 to
implement home networks will require cable
hops likely to exceed 10 meters.
Restricting the speed of the bus to S200
enables an increase in the distance
between nodes to about 14 meters
(approximately 45 feet). 1394 transceivers
have been announced that are powered by
in-wall wiring and extend the distance
between active nodes to at least 70 meters
using plastic optical fiber (POF).
What is a 1394 card?
A 1394 card (or 1394 expansion card,
board, or adapter) is add-on circuitry
designed to provide 1394 capabilities to a
computer that did not originally come with
1394. It consists of a standard-size rigid
material (fiberboard or something similar)
that plugs into one of the computer's
expansion slots in its motherboard (also
called the backplane).
What does peer-to-peer mean?
1394 is a peer-to-peer interface. This
allows dubbing from one camcorder to
another without the need for a computer.
Or, for example, you can stream A/V data
off a hard disk in real time, without
computer assistance. It also allows
multiple computers to share a given
peripheral without any special support in
the peripheral or the computers. It's
another important reason why 1394 is the
digital interface of choice and why its
acceptance is growing.
What is a 1394 "bus?"
You can think of a bus as a linear
electronic path on which several devices
share information. As you connect 1394
devices using a common series of cables,
you are connecting them to the 1394 bus.
(While this kind of bus can actually take
you to work in a manner of speaking it
does not require four wheels.)
What is a backplane?
A backplane is an electronic circuit
board containing circuitry and sockets
into which additional electronic devices
on other circuit boards or cards can be
plugged. In a computer, it is generally
synonymous with, or part of, the
motherboard.
What's the difference between DV and
1394?
DV is the actual format of the video
that comes out of your digital video
camera. It's a super high-resolution
format that exceeds the quality of S-VHS.
It even has many broadcast professionals
thinking about scrapping their BetaCam
equipment. The images are crisp, bright
and have excellent depth and contrast.
Best of all, the information is stored on
the video tape in digital form, so it can
be copied over and over without any loss.
1394 is the jack and protocol that lets
you transfer the DV data to your computer.
The full 1394 specification includes
frame-accurate device control and the
ability to read and write the digital
video.
What's the difference between DV video
over 1394, and video captured using a
video capture card?
Most of the high-resolution video
capture cards on the market use MJPEG
compression. The less you compress the
video, the better it looks, but the higher
the sustained data rate you need. At
compression under 6:1 (over 3000
kilobytes/sec) most people will think the
video looks as good as the original, but
in reality, it will be slightly lower
quality. The video will have very slight
artifacts and image loss.
In contrast, the DV spec is a 720x480
image size, at roughly a 5:1 compression.
More accurately, it is compressed at a
constant throughput of 3,600 kilobytes per
second which averages out to 5:1
compression.
Quality in. Quality out. What makes DV so
special is that when you capture DV
footage to your hard drive via 1394, the
DV video on your hard drive is an exact
digital copy of the original footage.
There is no loss. Every 1394 card delivers
the exact same DV-quality output. When
choosing a 1394 card, there is no video
quality debate regardless of the CODEC
(compression method) used.
What does daisy chain mean?
Daisy chaining is a wiring scheme in
which one device is wired to another which
is wired to another which is wired to
another, with the signal passed on from
device to device. For example, device A is
wired to device B, device B is wired to
device C, etc. All devices wired together
in this way can receive identical signals
or, in contrast to a simple bus, each
device in the chain may modify one or more
signals before passing them on. 1394
enables the daisy chaining of up to 64
devices which greatly reduces cabling
complexity.
What is hot swapping?
Hot swapping is the connection and
disconnection of computer peripherals or
other components while a system is turned
on, without interrupting system operation.
1394 enables hot swapping.
What does isochronous mean?
Isochronous data transmission
guarantees a certain minimum data rate,
such as required for time-dependent data
such as video or audio. Think about it.
Video and audio occur in continuous
streams. If there is a break in the signal
for just a moment, the quality of the
picture or sound suffers. 1394 is designed
to inherently provide isochronous service
as required for audio and video
communication.
What is the IEEE- Institute of
Electrical and Electronics Engineers?
IEEE is the world's largest technical
professional society, based in the USA.
Founded in 1884 by a handful of
practitioners of the new electrical
engineering discipline, today's Institute
has more than 320,000 members who
participate in its activities in 147
countries. The IEEE sponsors technical
conferences, symposia and local meetings
worldwide, publishes nearly 25% of the
world's technical papers in electrical,
electronics, and computer engineering and
computer science, provides educational
programs for its members and promotes
standardization. Areas covered include
aerospace, computers and communications,
biomedical technology, electric power and
consumer electronics.
What is the 1394 Trade Association?
The 1394 Trade Association was formed
in 1994 to facilitate adoption of 1394 by
consumer electronics and personal computer
manufacturers. The 1394 Trade Association
refers to IEEE 1394 as "The MultiMedia
Connection".
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