Pike
Technical
Manual
V5.2.3
37
FireWire
FireWire
Capabilities of IEEE1394a (FireWire 400)
FireWire
400
(S400)
is
able
to
transfer
data
between
devices
at
100,
200,
or
400
MBit/s
data
rates.
The
IEEE1394a
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
IEEE1394a,
which
established
a
common
communications
protocol
on
which
most
current
FireWire
cameras
are
based.
In
addition
to
common
standards
shared
across
manufacturers,
Allied
Vision
offers
Format_7
mode
that
provides
special
features
(smart
features),
such
as:
•
Higher
resolutions
•
Higher
frame
rates
•
Diverse
color
modes
as
extensions
(advanced
registers)
to
the
prescribed
common
set.
FireWire 800
FireWire
800
(S800)
was
introduced
commercially
by
Apple
in
2003
and
has
a
9-pin
FireWire
800
connector
(see
details
in
the
1394 Installation Manual
and
in
).
This
newer
IEEE1394b
specification
allows
a
transfer
rate
of
800
MBit/s
with
backward
compatibility
to
the
slower
rates
and
6-pin
connectors
of
FireWire
400.
The
IEEE1394b
capabilities
in
detail:
•
800
Mbit/s
•
All
previously
described
benefits
of
IEEE1394a
•
Interoperability
with
IEEE1394a
devices
•
Longer
communications
distances
(up
to
500
m
using
GOF
cables)
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.