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FireWire
800 (IEEE1394b) Overview
Introduction
The FireWire
interface technology, or IEEE specification 1394, was the result
of a joint venture between the electronics industry's most influential
consumers and computer manufacturers. This high-speed interface
technology was created specifically to make adding and removing
peripherals to and from a PC as easy as hooking up a telephone
to a wall jack. FireWire connections support plug-and-play installation
and device hot swapping, requiring no device ID, jumper or DIPswitch
settings. Video editing equipment, VCRs, cameras and audio players
are some of the products that frequently use FireWire connections.
FireWire
800 (FW800), or IEEE 1394b, was designed to double the speed
of the original FireWire 400 specification (IEEE1394a), while
still maintaining backward compatibility. FW800 is capable
of throughputs up to 800Mbps and its high-bandwidth, isochronous
(real-time) data interface provides one of the fastest peripheral
connections on the market today. With a 66% higher bandwidth
than the latest USB 2.0 (480Mbps) interface, FW800 offers
the fastest and easiest digital technology for connecting
consumer electronics with computer products.
With
low overhead and high data rates, FireWire has the ability
to mix real-time and asynchronous data on a single connection.
It can support multiple, uncompressed standard video streaming
and over 256 channels of MIDI. Ideal FireWire applications
include nonlinear (digital) video presentation and editing,
desktop and commercial publishing, document imaging, home
multimedia and personal computing, and even peer-to-peer networking.
Initially considered a purely consumer market technology,
FireWire is now supported by major professional recording
studios for their critical audio and video editing applications.
Major Benefits:
- High throughput satisfies
demanding audio and video editing requirements
- Hot swappable device
support allows user-friendly configuration
- Interfaces with
IDE devices to provide very cost-effective solutions
- Wide acceptance
and robust interoperability eases system compatibility
- Backward compatible
with earlier-generation FireWire devices
Competing Technologies:
The
FireWire technology development closely followed those earlier
accomplished by the USB (Universal Serial Bus) interface technology,
while incorporating new features that addressed some of USB's
shortcomings. Although USB 2.0 is capable of transfer speeds
of up to 480Mbps, its higher overhead hinders its performance
in comparison to FW800. Capable of sustaining the transfer rate
requirements of streaming video applications and hard disk connections,
FW800's transfer rate is over 60% faster than that of USB 2.0.
|
|
FireWire
800 (FW800)
|
FireWire
400 (FW400)
|
USB
2.0
|
USB
1.0
|
| Transfer
rate (Mbps) |
800
|
400
|
480
|
12
|
| Maximum
number of devices supported |
63
|
63
|
127
|
127
|
| Maximum
cable length |
300'
*
|
14'
|
15'
|
100'
|
| Hot-swap
support |
Yes
|
Yes
|
Yes
|
Yes
|
| Max.
Power Capable of Being Provided via Peripheral Ports |
45
Watts
|
45
Watts
|
2.5 Watts
|
2.5
Watts
|
| Pros
|
Ultra
high transfer rate
Supported by Apple and consumer electronics
Backward-compatible w/FW400 |
High
transfer rate
Supported by Apple and consumer electronics |
High
speed transfer rate
Backward-compatible with USB 1.0
Supports low cost peripherals |
All
PCs and Macs ship with USB ports
Supports low cost peripherals |
| Cons
|
Adapter cables required to connect to legacy FW ports
|
Not
compatible with USB
More expensive than USB 1.0 |
Emerging
technology, not widely available yet |
Slow
for streaming video and HD connection applications |
*
With optical cables
FireWire Connectors
|
FW400
(6-pin) to FW800 (9-pin)
|
FW800
(9-pin) to FW800 (9-pin)
|
Unlike
the standard FW400 cable connector, the FW800 connector actually
consists of nine pins. Data is sent via two separately shielded
twisted pair transmission lines (28 AWG). The two twisted pairs
are crossed in each cable assembly to create a transmit-receive
connection. Two more wires (22 AWG) carry power (8 to 40 V,
1.5 A max.) to remote devices. Two extra signal ground wires
are used for signal integrity and one pin remains unused. Currently,
the power lines are used to support small form factor hard drives
and recharging batteries on MP3 players.
The
4-pin and 6-pin connectors shown above are for use with legacy
FireWire (FW400) specification. The 4-conductor cable without
the two power lines is used for DV camcorders and DVCRs. Adapter
cables are used to connect four prongs on one side and nine
on the other. These adapter cables simply connect the data
lines while omitting the power connection. Devices will run
400Mbps when connected to a legacy port.
Longer
cable connections can be achieved by using plastic or glass
optical cables, currently not supported by StorCase products.
StorCase FireWire Product:
2-Bay Hybrid Data Silo DS321
- Dual
channel FW800 interface
- Integrated
Data Express DE110 removable drive carriers
- For
desktop or 1U rack mount applications (with standard extender
brackets)
| FireWire
Bridge |
Oxford
922 |
| Number
of FireWire Channels |
(2) |
| Number
of Drives Supported |
(2) |
| Version
Available w/Removable Carriers |
Yes |
| Rack
Mountable Dimensions (HxW) |
Yes1U
(1.73" x 16.06") |
| Supports
Desktop Applications |
Yes |
| Fan(s) |
Ultra-quiet,
5.5 CFMs |
| Fan
Speed Control |
Manual
On/Off Override |
| Power
Supply |
45
Watts |
| Audible
Alarm Mute Option |
Yes |
| MTBF
/ Warranty |
500K
Hours/7 Years |
| List
Price |
$643 |
|
