SVS-Vistek exo174, Manual

Page: 36 / 160

SVS-VISTEK
Feature description 36
5.2 Camera Features
5.2.1 Basic Capture Modes
Free Running
Free running (fixed frequency) with programmable exposure time. Frames
are readout continously and valid data is indicated by LVAL for each line
and FVAL for the entire frame.
There is no need to trigger the camera in order to get data. Exposure time
is programmable via serial interface and calculated by the internal logic
of the camera.
NOTICE
The fundamental signals are:
Line Valid: LVAL, Frame Valid: FVAL,
And in case of triggered modes: trigger input.
Triggered Mode (pulse width)
External trigger and pulse-width controlled exposure time. In this mode
the camera is waiting for an external trigger, which starts integration and
readout. Exposure time can be varied using the length of the trigger pulse
(rising edge starts integration time, falling edge terminates the integration
time and starts frame read out). This mode is useful in applications where
the light level of the scene changes during operation. Change of
exposure time is possible from one frame to the next.
Exposure time of the next image can overlap with the frame readout of
the current image (rising edge of trigger pulse occurs when FVAL is high).
When this happens: the start of exposure time is synchronized to the
falling edge of the LVAL signal.