JAI CV-A11 User Manual

Page of 25
CV-A11
 
6. Functions and Operations 
Apart from the standard continuous operation, the CV-A11 features three external asynchronous 
trigger modes (edge pre-select, pulse width controlled and start/stop) and a special frame-delay 
readout mode. Long integration time mode is also supported. 
In addition, the CV-A11 also provides a partial scan readout function. 
6.1. Basic functions 
Some of the primary camera functions need a general introduction before the operation modes 
are described. The list below shows the primary functions from the command list. 
 
 
SM  Shutter Mode 
Normal shutter, Programmable Exposure 
 
SH  Shutter Speed 
Off to 1/100,000 second 
 
PE 
Programmable Exposure  1.5 H to 1023.5 H 
 
SC 
Scanning Format 
Full frame, 1/2 partial, 1/3, 1/6 partial 
 
TR  Trigger Mode 
Normal, Edge, PWC, frame delay readout 
 
 
 
Long time exposure, start-stop, smearless (Edge) 
 
HC  HD Accumulation 
H Synchronous, H Asynchronous. 
 
The shutter SM can be set to normal (SM=0), where the exposure time is selected from 15 fixed 
step with the command SH, or programmable exposure (SM=1). Here the command PE allows 
1023 step with 1 line period resolution (63.5 µs) in triggered mode. For normal mode, PE can be 
up to 523 for full, 275 for 1/2, 195 for 1/3 and 115 for 1/6 partial scan. 
The CCD scanning format SC can be selected between full or partial scanning. With partial 
scanning, only the vertical central part of the CCD sensor is read out with a higher frame rate. 
The partial scan is done by a fast dump read out of the lines in the vertical ccd register down to 
the top of the partial image. The partial part of the image is read out with normal speed.  The 
lines below the partial image are read out and dumped with a high speed.  
Imaged scene
Partial scanning.
Aspect ratio correct
648 pixels 
1/2
 P
S
, 24
0
pi
xel
s
1/6
 P
S
, 80
pi
xel
s
1/
3 PS,
 16
0
p
ix
el
s
Imaged scene
Partial scanning.
Aspect ratio correct
648 pixels 
1/2
 P
S
, 24
0
pi
xel
s
1/6
 P
S
, 80
pi
xel
s
1/
3 PS,
 16
0
p
ix
el
s
Fig. 8. Partial scanning. 
 
The accumulation mode HC is H synchronous (HC=0). For PWC mode (TR =2) and Frame Delay 
readout (TR=3) it can also be set to asynchronous accumulation (HC=1). 
In H synchronous mode, the exposure in will start at the first HD pulse after the trigger falling 
edge.  In H asynchronous mode the exposure will start immediately at the leading edge of the 
trigger pulse without waiting for the HD. Fig. 9 and fig. 10 shows the details.
 
HD
Trigger
X b
Accum
HD
Trigger
X b
Accum
 
Fig. 9. PWC H synchronous accumulation.                  Fig 10. PWC asynchronous accumulation. 
 
In normal continuous mode (TR=0) shutter speed up to 1/100,000 second can be used. In 
triggered shutter modes, the shortest shutter time is limited to ≥1,5 H or 1/10,000. In triggered 
shutter modes with full and partial scan, the exposure time is not limited to the frame read out 
time. It can be longer. 
 
- 6 -