Basler ace acA1920-155, User Manual, Page: 305 / 326

AW00123404000 Features
Basler ace USB 3.0 295
8.18 Chunk Features
8.18.1 What are Chunk Features?
In most cases, enabling a camera feature will simply change the behavior of the camera. The Test
Image feature is a good example of this type of camera feature. When the Test Image feature is
enabled, the camera outputs a test image rather than a captured image.
When chunk features are enabled, the camera develops some sort of information about each image
that it acquires. In these cases, the information is added to each image as a trailing data "chunk"
when the image is transferred to the host PC. Examples of this type of camera feature are the frame
counter feature and the time stamp feature. For example, when the Gain chunk is used, the camera
checks, after an image is captured, the gain All parameter value used for the image acquisition and
develops a data chunk to be appended to the image data. And if the time stamp chunk feature is
enabled, the camera develops a time stamp data chunk. The gain and the timestamp data chunks
would be added as trailing data to each image as the image is transferred from the camera. The
features that add chunks to the acquired images are referred to as “chunk” features.
After the data chunks were transmitted to the PC they must be retrieved. For more information
about retrieving chunk data, see Section 8.18.4 on
page 303 .
8.18.2 Chunk Mode Active
When Chunk Mode Active is enabled, the camera is in a state where it can generate and append
chunk data to image data and transmit them to the PC.
Note: Chunk data can only be appended to image data when Chunk Mode Active is enabled.
Disabling Chunk Mode Active prevents chunk data from being to be appended to image data.
Chunk features are not available for the acA1920-155 camera.