Camera modes of operation 99
Control mode
In control mode, the exposure time is controlled by the frame grabber. Usually,
the camera is triggered asynchronously. An external trigger signal is provided to
the frame grabber. The frame grabber sends an exposure signal to the camera.
Control mode is similar to asynchronous reset mode except in this mode, the
camera is resynchronized on the exposure signal. The width of the exposure signal
Y determines the exposure time.
❖ You can adjust the width of the exposure signal on the frame grabber, using Matrox
R Intellicam to modify the DCF file or using MIL.
A 5 Some cameras will ignore an exposure signal that arrives before the current frame
period is over, while others will resynchronize on this new pulse, discarding all
IN 0 current information. To avoid losing information, the shortest time between
external trigger pulses should be greater than the sum of the exposure signal width
0 and the frame transfer time.
IM 2 The signals used in this mode are an external trigger signal provided to the frame
grabber, an exposure signal supplied by the frame grabber to the camera, and the
video output and synchronization signals provided to the frame grabber.
L Y ❖ Use the control mode when control over the start and exposure time of an image
PRE19 MA is required.
