Acquisition Timing Chart - GigE VA Series User Manual

8.7

Acquisition Timing Chart

Figure 8.11 shows a timing chart for frame acquisition and transmission. The chart assumes that exposure is
triggered by an externally generated exposure start trigger signal, that the Trigger Activation parameter is set to
Rising Edge and that the Exposure Mode parameter is set to Timed.
As shown in the figure below, there is a slight delay between the rise of the exposure start trigger signal and the
start of exposure. After the exposure time for a frame acquisition is complete, the camera begins reading out the
acquired frame data from the imaging sensor into a frame buffer in the camera. When a sufficient amount of
frame data has accumulated in the frame buffer, the camera will begin transmitting the data to your computer.
This buffering technique avoids the need to exactly synchronize the clock used for sensor readout with the data
transmission. The camera will begin transmitting data when it has determined that it can safely do so without
over-running or under-running the buffer.

Exposure Start Delay:
where the trigger signal rises and the point where exposure actually begins

Frame Readout time:
sensor into the frame buffer

Frame Transmission time:
frame buffer in the camera to your computer

Transmission Start Delay:
the acquired frame data from the sensor and the point where it begins transmitting the acquired frame data
from the buffer to your computer
the amount of time (including trigger jitter and latency) between the point
the amount of time it takes to read out the frame data from the imaging
the amount of time it takes to transmit an acquired frame data from the
the amount of time between the point where the camera begins reading out
Figure 8.11 Timing Chart (not drawn to scale)
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VA GigE series
RA14-131-003