User`s manual
AW00098504000 Image Acquisition Control
Basler ace Camera Link 115
7.7 Acquisition Timing Chart
Figure 34 shows a timing chart for frame acquisition and transmission. The chart assumes that
exposure is triggered by an externally generated frame start trigger (ExFSTrig) signal with rising
edge activation and that the camera is set for the timed exposure mode.
As Figure 34 shows, there is a slight delay between the rise of the ExFSTrig signal and the start of
exposure. After the exposure time for a frame acquisition is complete, the camera begins reading
out the acquired image data from the imaging sensor. After a short delay, the camera will begin
transmitting image data from the camera to the host PC.
The exposure start delay is the amount of time between the point where the trigger signal
transitions and the point where exposure actually begins.
Note that, if the debouncer feature is used, the debouncer setting for the input line must be added
to the exposure start delay shown in Figure 34 to determine the total start delay.
The frame readout time is the amount of time it takes to read out the data for an acquired frame
from the imaging sensor. This time period will vary depending on several camera settings such as
the image AOI, the Camera Link tap geometry, the Camera Link pixel clock speed, and others. As
explained below, you can read the value of the Readout Time parameter to determine the sensor
readout time given the current camera settings.
The frame transmission time is the amount of time it takes to transmit an acquired frame from the
buffer in the camera to the host PC via the network. The frame transmission time will always be
equal to the frame readout time.
The transmission start delay is the amount of time between the point where the camera begins
reading out the acquired frame data from the sensor to the point where it begins transmitting the
data for the acquired frame from the buffer to the host PC.
FTWait
Signal
ExFSTrig
Signal
Exposure
Frame
Readout
Frame
Transmission
Exposure
Frame N
Frame N+1 Readout
Frame N+1 Transmission to Host PC
Frame N Readout
Frame N Transmission to Host PC
Exposure
Frame N+1
Exposure
Frame N+2
Transmission Start Delay (65 to 200 µs)
Timing charts are not drawn to scale
Exposure Start Delay ( 39 µs)
Fig. 34: Exposure Start Controlled with an ExFSTrig Signal
Exposure Start Delay ( 39 µs)
Transmission Start Delay (65 to 200 µs)