What is Firewire

Firewire is a very fast external bus standard that supports data transfer rates of up to 400Mbps (in 1394a) and 800Mbps (in 1394b). Products supporting the 1394 standard go under different names, depending on the company. Apple, which originally developed the technology, uses the trademarked name FireWire. Other companies use other names, such as i.link and Lynx, to describe their 1394 products.

IEEE-1394 (also known as 1394-1995 or Firewire) refers to a standard set by the Institute of Electrical and Electronic Engineers. IEEE has long been responsible for setting many standards over the years, including 1394. This standard defines a serial bus similar to USB but with much higher-speed capabilities. The current supported speeds are from 100 to 400Mbs, and future improvements are expected to allow up to 1Gbs performance, all over twisted pair wire.

A single 1394 port can be used to connect up 63 external devices. In addition to its high speed, 1394 also supports isochronous data -- delivering data at a guaranteed rate. This makes it ideal for devices that need to transfer high levels of data in real-time, such as video devices. Like USB, 1394 supports both Plug-and-Play and hot plugging, and also provides power to peripheral devices.

All camcorders use a 4-pin connector for their 1394 interface. Nearly all computers use a 6-pin connector for their 1394 interface. So, you need a 6-pin to 4-pin configuration to connect a computer to a camcorder. If you want to transfer video between two camcorders then you need a 4-pin to 4-pin configuration. Firewire drives usually use the 6-Pin Configuration.

Cabling and topology of 1394

IEEE-1394 is usuable in both tree (similar to star) and daisy-chain topologies, or a combination of the two. In any case, cable length is limited to about 15 feet between devices. Provisions allow for up to 1023 buses and up to 63 nodes per bus, which translates into a very large number of devices!

Firewire Connectors

- 4 Pin Firewire Connector

- 6 Pin Firewire Connector

Types of Firewire Cables

• 6-Pin 6 Wire Cables
• The 6 conductor type has two seperately shielded twisted pairs for data and two power wires in an overall shielded cable with 6-pin connectors on either side.
• 4-Pin 4 Wire Cables
• The 4 wire cable uses two seperately shielded data cables without power wires in an overall shielded cable with 4-pin connectors on either end.
• 6-Pin to 4-Pin Cables
• This cable uses either type of actual cable, with a 6-pin connector on one side, and a 4-pin connector on the other side of the cable.

What are the length limitations?

• Standard 28 AWG Wire - 4.5 Meters maximum
• Fiber Optic Systems can extend the distance to 500 Meters

Uses for Firewire

Used for high-speed serial applications: cameras, scanners, storage devices, etc. Allows for transfer speeds up to 400Mbs. With its high bandwidth and fast speed these cables are great for use in desktop publishing, document processing, and multimedia applications.