IEEE 1394   











IEEE-1394, Firewire, iLink Cabling

IEEE 1394, Firewire, and iLink all refer to the same set of communication standards but the most common name is "Firewire".  Firewire is a standard for connecting devices for the purpose of transferring various types of data such as audio, video or files on a computer. Many Firewire devices can be plugged into each other with Firewire cables, and they can communicate with each other as peers (without a computer as a host). In addition, Firewire devices also configure themselves to communicate automatically whenever a new device is added to a Firewire chain (see below). Note that faster Firewire devices will not be able to communicate at top speed if you place a slower device in between them on the Firewire chain.

Sample IEEE 1394 Firewire Chain:

               | DVD |-----------| VCR |-----------| Digital Camera |----------| Computer |

IEEE 1394 Firewire cables are constructed of 6-wire shielded cable. Two wires are used to transmit, and two are used to receive data across a Firewire chain. The other two wires provide power to the Firewire chain. Firewire cables with 4-pin connectors do not provide the power wires. In other words, Firewire devices (including Firewire hubs and repeaters) can repeat a signal an additional 15 feet if they have power (from a 6-pin connection). Remember, you cannot provide power to a device via a cable with a 4-pin connector on it (and this is why Firewire repeaters have 6-pin connections).

Under the current IEEE 1394 specifications, a data transfer rate of up to 400Mbps is possible with a maximum cable distance of up to 15 feet (4.5 meters) between devices. However, Firewire devices and repeaters will repeat a signal and allow you to extend a Firewire chain an additional 15 feet (4.5 meters). You can add devices and repeaters for a total Firewire chain length of up to 225 feet (68.5 meters). Note: "Mbps" (with a small "b") means mega"bits" per second, not mega"bytes" per second which has a big "B"). Since 1 "byte" equals 8 "bits", 400 megabits pers second (Mbps) equals 50 megabytes per second (MBps). (400 divided by 8 equals 50.)


Startside ] Opp ] [Søk]

Copyright © 2002 Øyvind Haugland
Sist endret:  13 januar 2019

  Interested in this stuff? Please write to:

HTML Counter            stats counter