Dalsa C1240, Руководство пользователя

Страница: 179 / 327

Nano Series GigE Vision Camera Operational Reference • 169
Using Cycling Presets—a Simple Example
As presented in this category’s overview, the cycling preset features allows setting up camera
configurations that can change dynamically and repeatedly, with minimum overhead. The features
that change along with the trigger for the feature change are preprogrammed in the camera.
Additionally a set of preset features can be updated while the camera is acquiring with a different
preset. Such dynamic feature changes allow applications to perform tracking algorithms.
The following example describes a simple cycling sequence (using free running acquisitions) with
exposure change steps which will repeat until stopped by the user. This example uses the Sapera
tool CamExpert to set features and test the sequence.
Multi-Exposure Cycling Example Setup
• For this example, first configure a free running acquisition of 20 fps with an exposure time
that’s somewhat short (dark). These controls are in the Sensor Control Category group
within CamExpert.
•
Now select the Cycling Preset Category to setup and test the following example.
• Set cyclingPresetMode to Active. This feature enables the Cycling Preset Module.
•
Set cyclingPresetCount to the number of presets which will be configured and used. For this
example set this to 4.
•
Set the feature cyclingPresetIncrementalSource to the event which will be used to
increment the cycling presets index. For this example, set this feature to StartOfFrame
which is a logical choice in a free-running acquisition setup.
• Set the feature cyclingPresetRepeater to the number of incremental source events to count
before switching to the next preset. In this example we are counting StartOfFrame events,
thus a value of 20 (with a test setup of 20 fps) will switch presets every 1 second.
• The feature cyclingPresetResetSource is optional for this example. This defines the event
which will reset the preset index back to 1. In this example, by setting the feature to
EndOfAcquisition we know that when Freeze is clicked in CamExpert to stop the free-
running acquisition, the cycling preset index is returned to the start (1).
•
Set PresetConfigurationSelector to index 1.
•
Set FeaturesActivationSelector to ExposureTime (the exposure initially set as somewhat
dark).
•
Set FeaturesActivationMode to Active. This defines the camera exposure as one variable
stored in this preset index 1.
• The feature ExposureTime shows the last exposure time used by the camera (when cycling
was not enabled). This field now controls the camera exposure time. The primary exposure
time field in the Sensor Control Category is in gray text indicating a read only field.
•
Set PresetConfigurationSelector to index 2.
• Set the feature ExposureTime to a higher value, increasing the acquisition brightness.
•
Repeat for index 3 with an exposure a bit longer again, and index 4 with an even longer
exposure.
Test the Example
•
With 4 different exposure times saved in four presets, click the CamExpert Grab button to
start the cycling free-running acquisition.
•
The CamExpert live display window will show a live grab of 20 fps, where each second
shows a four step increase in exposure, which then returns to the first exposure cycling
continuously until stopped by the user.