Allied Vision Technologies F-201B AVT Dolphin Manual page 46

The recommended limit for transferring isochronous image data is 1000q (quadlets) per
cycle or 4096 bytes (with 400 Mb/s of bandwidth).
The table shows that the camera has to send 2560 pixels or 2 lines of video per cycle
when using an F-201B camera in format 2 mode 2 (1280 x 960 pixels, 8 bits per pixel)
at 15 fps. The camera thus uses 64% of available bandwidth. If the frame rate is
reduced to 7.5 fps the camera needs only 32% of the bandwidth. This allows up to three
cameras with these settings to be operated on the same bus.
If the cameras are operated with an external trigger the maximum trigger frequency
may not exceed the highest frame rate, so preventing frames from being lost.
The frame rates in video modes 0 to 2 are specified and set by IIDC v. 1.3.
In video Format_7 this can be set dynamically by the parameters described below.
The following formula is used to calculate the highest frame rate in Format_7.
= =
FPS FPS
In CCD
T
=
µ
⋅ +
2 63 , 37 s 15
200,00
180,00
160,00
140,00
120,00
100,00
80,00
60,00
40,00
20,00
0,00
0 200
AoiHeight
1236
1200
1024
960
600
480
Available bandwidth on the 1394 bus may limit the frame rate possible.
46
1
+ +
T T
Ch arg eTrans Black
µ
⋅ + −
4 1 , s ( 1236 AoiHeight
FPS=f(AoiHeight)
400 600 800
AoiHe ight
FPS AoiHeight
12,74
13,09
15,16
16,09
24,50
29,67
+
T
Dump Scan
1
µ
⋅ +
) 4 1 , s
1000 1200 1400
240 51,33
120 80,85
60 113,48
30 142,17
15 162,74
-
µ
⋅
AoiHeight 63 , 37
FPS
FPS
-
s