User`s manual

Image Acquisition Control
Basler aviator Camera Link 85
5.6 Acquisition Timing Charts
Timing charts for frame acquisition and transmission appear at the end of this section. The charts
assume that exposure is triggered by an externally generated frame start (an ExFSTrig) signal with
rising edge activation and that the camera is set for the timed exposure mode.
As the timing charts show, there is a slight delay between the rise of the ExFSTrig signal and the
start of exposure. After the exposure time for an image acquisition is complete, the camera begins
reading out the acquired image data from the imaging sensor into a buffer in the camera. This
buffering technique avoids the need to exactly synchronize the clock used for sensor readout with
the data transmission over the Camera Link connection and is an important element in achieving
the highest possible frame rate with the best image quality.
The charts also show that there is a delay between the point where the camera begins reading
image data out of the imaging sensor and when it starts transmitting the data from the image buffer
to the host PC. The duration of this delay varies significantly depending on whether the camera is
set for the 1X2-1Y or the 1X-2YE Camera Link tap geometry. When set for the 1X2-1Y geometry,
the camera must read out and buffer the entire image before it begins transmitting image data.
When set for the 1X-2YE geometry, the camera will begin transmitting image data before it has read
out and buffered the entire image. This difference in the starting point of image data transmission
is the main difference between the two timing charts.
In the timing charts:
 The exposure start delay is the amount of time between the point where the frame start
trigger signal transitions and the point where exposure actually begins.
 The frame readout time is the amount of time it takes to read out the data for an acquired
image from the sensor into the image buffer.
 The transmission start delay is the amount of time between the point where the camera
begins reading image data out of the sensor to the point where the camera begins transmitting
the data from the image buffer to the host PC.
 The frame transmission time is the amount of time it takes to transmit the acquired image
from the buffer in the camera to the host PC via the Camera Link interface.
The table below shows the exposure start delay for each camera model:
Camera Model Exposure Start Delay
avA1000-120km/kc 36 µs
avA1600-65km/kc 51 µs
avA1900-60km/kc 59 µs
avA2300-30km/kc 71 µs
Table 9: Exposure Start Delays