Data Translation DT3130 Series, Руководство пользователя

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Chapter 2
34
Passthru Operations
In a passthru operation, a DT3130 Series board continuously captures
and displays video data until you stop the operation. Typically, you
use passthru to view images (in as close to real time as possible for
the configuration and passthru method chosen) for the purpose of
focusing or positioning the camera.
In addition to displaying passthru data, you can continuously store
the data to user-allocated buffers in host memory, if desired. This
operation is called continuous-acquire passthru mode.
This section describes the following aspects of passthru:
• Passthru modes,
• Source origin, and
• Overlays
Passthru Modes
DT3130 Series boards support bitmap passthru mode and
continuous-acquire passthru mode. This section describes these
modes.
Bitmap Passthru Mode
DT3130 Series boards support asynchronous bitmap passthru mode.
In an asynchronous operation, the operation starts but gives control
to you immediately, allowing you to perform other operations while
data is displayed.
Bitmap passthru mode requires a frame in device memory into which
the image is captured.