Matrix Vision mvBlueFOX, Техническое руководство, Страница: 253 / 255

246 CONTENTS
Mode Description
Continuous Free running, no external trigger signal needed.
OnDemand Image acquisition triggered by command (software trigger).
OnLowLevel Start an exposure of a frame as long as the trigger input is below the trigger threshold .
OnHighLevel Start an exposure of a frame as long as the trigger input is above the trigger threshold.
OnHighExpose Each rising edge of trigger signal acquires one image, exposure time corresponds to pulse
width.
See also
Using external trigger with CMOS sensors (p. 160)
21.5.2.2.2 Erase, exposure and readout
All pixels are light sensitive at the same period of time. The whole pixel core is reset simultaneously and after the
exposure time all pixel values are sampled together on the storage node inside each pixel. The pixel core is read
out line-by-line after exposure.
Note
Exposure and read out cycle is carry-out in serial; that causes that no exposure is possible during read out.
The step width for the exposure time is 1 us.
Image data is then shifted out line-by-line and transferred to memory.
To calculate the maximum frames per second (FPS
max
) in snapshot mode you will need following formula:
FrameTime = (Imag 900) * ((Image 9) / PixelClock)
FPS_max = 1
------------------------------------
(Fra ExposureTime)
21.5.2.3 Use cases
As mentioned before,
"Global reset release"
will only make sense, if a flash is used which is brighter than the
ambient light. The settings in
wxPropView
(p. 77) will look like this:
In this case, DigOut0 gets a high signal as long as the exposure time (which is synchronized with the GlobalReset
← -
Release). This signal can start a flash light.
21.5.3 Measured frame rates
MATRIX VISION GmbH