FireWire
STINGRAY Technical Manual
V2.2.0
33
FireWire Plug & play capabilities
FireWire devices implement the ISO/IEC 13213
configuration ROM
model for
device configuration and identification, to provide plug & play capability. All
FireWire devices are identified by an IEEE EUI-64 unique identifier (an exten-
sion of the 48-bit Ethernet MAC address format) in addition to well-known
codes indicating the type of device and protocols it supports. For further
details read Chapter
Configuration of the camera
on page 218.
FireWire hot-plug and screw-lock precautions
Caution
a
Hot-plug precautions
•
Although FireWire devices can
theoretically
be hot-
plugged without powering down equipment,
we
strongly recommend turning the computer power off,
before connecting a digital camera
to it via a FireWire
cable.
•
Static electricity or slight plug misalignment during
insertion may short-circuit and damage components.
•
The physical ports
may be damaged
by
excessive ESD
(electrostatic discharge), when connected under pow-
ered conditions. It is good practice to ensure proper
grounding of computer case and camera case to the
same ground potential, before plugging the camera
cable into the port of the computer. This ensures that
no excessive difference of electrical potential exists
between computer and camera.
•
As mentioned earlier, it is
very
important
not
to exceed
the
inrush energy of 18 mJoule in 3 ms
. (This means
that a device, when powered via 12 V bus power must
NEVER draw more than 1.5 A, but only 0.5 A in the first
3 ms, assuming constant flow of current.)
•
Higher inrush current over longer periods
may damage
the physical interface chip of the camera and/or the
phy chip in your PC
. Whereas inrush current is not a
problem for one Stingray camera, daisy chaining multi-
ple cameras or supplying bus power via (optional)
HIROSE power out to circuitry with unknown inrush cur-
rents needs careful design considerations to be on the
safe side.
Screw-lock precautions
•
Also, all AVT 1394b camera and cables have
industrial
screw-lock fasteners
, to insure a tight electrical con-
nection that is resistant to vibration and gravity.
•
We strongly recommend using only 1394b adapter
cards with screw-locks.