FireWire
STINGRAY Technical Manual
V2.2.0
21
Why use FireWire?
Digital cameras with on-board
FireWire
(IEEE 1394a or 1394b) communica-
tions conforming to the IIDC standard (V1.3 or V1.31) have created cost-
effective and powerful solutions options being used for thousands of differ-
ent 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 fibre cabling
•
Forwards and backward compatibility blending 1394a and 1394b
•
Both real-time (isochronous) and demand-driven asynchronous data
transmission capabilities
FireWire in detail
Serial bus
Briefly summarized,
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,
such as gain and shutter, on the fly. 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.