Data Translation DT3152-LS, Руководство пользователя

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Chapter 2
52
Acquisition Operations
The DT3152-LS frame grabber board can acquire images either
synchronously or asynchronously, as follows:
• Synchronous acquisition
−
All your system resources are
devoted to the acquisition. You cannot perform another operation
until the synchronous acquisition completes.
• Asynchronous acquisition
−
The operation starts and then
returns control to you immediately, allowing you to perform
other operations while data is acquired.
The DT3152-LS board uses the following memory locations:
• Device memory
−
A contiguous location in system memory that
is managed by the DT3152-LS Device Driver. You define the size
of this memory location when you configure the device driver.
• Host memory
−
Host memory does not have to be contiguous.
You must allocate and manage this memory location.
Both device memory and host memory are volatile memory locations,
meaning that their contents may be overwritten with each
acquisition.
For area-scan operations, you can acquire a single frame to either
device memory or host memory; you can acquire multiple frames to
device memory only. For line-scan operations, you can acquire lines
to host memory only.
Refer to Appendix D for more information on using memory.
Note: In line-scan mode, you can continuously acquire and/or
display images using continuous-acquire passthru mode. For more
information, refer to
page 48 .