User Manual

FireWire
Guppy PRO Technical Manual V4.0.0
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FireWire also supports multiple hosts per bus. FireWire requires only a cable
with the correct number of pins on either end (normally 6 or 9). It is
designed to support plug-and-play and hot swapping. It can supply up to
45 W of power per port at 30 V, allowing high consumption devices to oper-
ate without a separate power cord.
Capabilities of 1394a (FireWire 400)
FireWire 400 (S400) is able to transfer data between devices at 100, 200 or
400 MBit/s data rates. Although USB 2.0 claims to be capable of higher
speeds (480 Mbit/s), FireWire is, in practice, not slower than USB 2.0.
The 1394a capabilities in detail:
• 400 Mbit/s
• Hot-pluggable devices
• Peer-to-peer communications
• Direct Memory Access (DMA) to host memory
• Guaranteed bandwidth
• Multiple devices (up to 45 W) powered via FireWire bus
IIDC V1.3 camera control standards
IIDC V1.3 released a set of camera control standards via 1394a which estab-
lished a common communications protocol on which most current FireWire
cameras are based.
In addition to common standards shared across manufacturers, a special
Format_7 mode also provided a means by which a manufacturer could offer
special features (smart features), such as:
•higher resolutions
• higher frame rates
•diverse color modes
as extensions (advanced registers) to the prescribed common set.
Capabilities of 1394b (FireWire 800)
FireWire 800 (S800) was introduced commercially by Apple in 2003 and has
a 9-pin FireWire 800 connector (see details in Hardware Installation Guide
and in Chapter IEEE 1394b port pin assignment on page 70). This newer
1394b specification allows a transfer rate of 800 MBit/s with backward com-
patibilities to the slower rates and 6-pin connectors of FireWire 400.
Caution

While supplying such an amount of bus power is clearly a
beneficial feature, it is very important not to exceed the
inrush current of 18 mJoule in 3 ms.
Higher inrush current may damage the Phy chip of the
camera and/or the Phy chip in your PC.