Pike
Technical
Manual
V5.2.3
35
FireWire
FireWire
Why use FireWire?
Digital
cameras
with
on-board
FireWire
(IEEE1394a
or
IEEE1394b)
communications
conforming
to
the
IIDC
standard
(V1.3
or
V1.31)
have
created
cost-effective
and
powerful
solutions
options
being
used
for
thousands
of
different
applications
around
the
world.
FireWire
is
currently
the
premier
robust
digital
interface
for
industrial
applications
for
many
reasons,
including:
•
Guaranteed
bandwidth
features
to
ensure
fail-safe
communications
•
Interoperability
with
multiple
different
camera
types
and
vendors
•
Diverse
camera
powering
options,
including
single-cable
solutions
up
to
45
W
•
Effective
multiple-camera
solutions
•
Large
variety
of
FireWire
accessories
for
industrial
applications
•
Availability
of
repeaters
and
optical
fiber
cabling
•
Forward
and
backward
compatibility
blending
IEEE1394a
and
IEEE1394b
•
Both
real-time
(isochronous)
and
demand-driven
asynchronous
data
transmission
capabilities
FireWire in detail
Serial bus
FireWire
is
a
very
effective
way
to
utilize
a
low-cost
serial
bus,
through
a
standardized
communications
protocol,
that
establishes
packetized
data
transfer
between
two
or
more
devices.
FireWire
offers
real-time
isochronous
bandwidth
for
image
transfer
with
guaranteed
low
latency.
It
also
offers
asynchronous
data
transfer
for
controlling
camera
parameters
on
the
fly,
such
as
gain
and
shutter.
As
illustrated
in
the
diagram
below,
these
two
modes
can
co-exist
by
using
priority
time
slots
for
video
data
transfer
and
the
remaining
time
slots
for
control
data
transfer.
Figure 2: IEEE1394a data transmission
