Increasing The Maximum Allowed Frame Rate - Basler acA2040-55 User Manual

AW00123409000

6.10.2 Increasing the Maximum Allowed Frame Rate

You may find that you would like to acquire frames at a rate higher than the maximum allowed with
the camera's current settings. In this case, you must adjust one or more of the factors that can
influence the maximum allowed rate and then check to see if the maximum allowed rate has
increased:
Decreasing the height of the Image ROI can have a significant impact on the maximum

allowed frame rate. If possible in your application, decrease the height of the Image ROI.
If you are using normal exposure times and you are using the camera at it's maximum

resolution, your exposure time will not normally restrict the frame rate. However, if you are
using long exposure times or small regions of interest, it is possible that your exposure time is
limiting the maximum allowed frame rate. If you are using a long exposure time or a small ROI,
try using a shorter exposure time and see if the maximum allowed frame rate increases. (You
may need to compensate for a lower exposure time by using a brighter light source or
increasing the opening of your lens aperture.)
The frame transmission time will not normally restrict the frame rate. But if you are using

multiple cameras connected to one hub, you may find that the transmission time is restricting
the maximum allowed rate. In this case, you could use a multiport host adapter in the computer
instead of a hub.
If you are working with an acA1920-25, acA2500-14, acA3800-14 or acA4600-10 camera:
Use the rolling mode rather than the global reset release mode. The rolling mode allows overlapping
frame acquisition while the global reset release mode does not. Overlapping frame acquisitions is,
however, necessary for achieving the highest frame rates.
If you are working with an acA640-750, acA800-510, acA1300-200, acA1920-150 or acA2500-60
camera:
Using the fast sensor readout mode instead of the normal sensor readout mode can increase

the maximum allowed frame rate. For more information about sensor readout modes, see
Section 6.6.1.1 on
You can increase the maximum allowed frame rate by decreasing the ROI width, provided the

ROI width is above 256 pixels. For small ROIs less than 256 pixels wide, maximum allowed
frame rate can not be decreased by decreasing the ROI width.
An important thing to keep in mind is a common mistake new camera users
frequently make when they are working with exposure time. They will often use a
very long exposure time without realizing that this can severely limit the camera's
maximum allowed frame rate. As an example, assume that your camera is set to
use a 1/2 second exposure time. In this case, because each frame acquisition will
take at least 1/2 second to be completed, the camera will only be able to acquire
a maximum of two frames per second. Even if the camera's nominal maximum
frame rate is, for example, 100 frames per second, it will only be able to acquire
two frames per second because the exposure time is set much higher than
normal.
For more information about Image ROI settings, see Section 7.6 on
For more information about the rolling mode, see Section 6.6.2 on
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Image Acquisition Control
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