13
Functions
DFW-SX910/X710
IIDC Extended
Features
Following are vender-unique features, which are not
defined by the IIDC standard.
Memory Shot
Memory Shot allows the camera to collect one or more
images into on-board image memory without tying up
available 1394 bus bandwidth. Normally, a 1394 IIDC
camera transmits a new image immediately after the
acquisition so the 1394 bus bandwidth is pre-allocated
to the camera to ensure deterministic performance.
1394 bus bandwidth is allocated based on resolution
and frame rate assigned. Multiple camera
configurations frequently demand more bandwidth (or
more ISO channels) than available on a single 1394
bus. The user can either reduce the bandwidth
required by each cameras by reducing the frame rate or
resolution or increase available bandwidth by adding
more 1394 busses on one or more computers. Memory
Shot offers another alternative to managing the 1394
bus bandwidth in multiple camera configurations. This
is especially useful in hardware triggered
environments. Multiple cameras can be setup to
acquire one or more images simultaneously without
consuming any 1394 bus bandwidth. The applications
software can setup the multiple cameras on a single
1394 bus on one computer for Memory Shot
acquisition, query the camera to verify that the
image(s) are in the camera on-board memory, and tell
each camera to transmit its stored image(s). These
cameras have 128 Mbit of frame memory.
It can hold:
1280
×
960 at YUV4:2:2 is 6 images
1280
×
960 at YUV4:1:1 is 9 images
1280
×
960 at MONO8 is 13 images
The number of images (N) that can be holded is
defined by the image size and color coding.
N = 16 * 1024 * 1024 (byte) / ( W * H * K )
W: image width (pixels)
H: image hight (pixels)
K: coefficient of color coding
K
color coding
1
Mono8/Raw8
1.5
YUV4:1:1
2
YUV4:2:2
Trigger input
Trigger input
Conventional system
Power repeater
1394
1394
1394
1394
1394
Images input
from CCD
Acquisition
phase
image 1
image 2
image 3
Transmission
phase
image 1
image 2
image 3
Images output to
1394 bus
You can specify the timing of the
transmission of the stored images.
128 Mbit
frame memory