National Instruments IEEE 1394 用户手册

DLL

Dynamic Link Library—A software module in Microsoft Windows 
containing executable code and data that can be called or used by Windows 
applications or other DLLs; functions and data in a DLL are loaded and 
linked at run time when they are referenced by a Windows application or 
other DLLs.

driver

Software that controls a specific hardware device, such as an IEEE 1394 
camera.

endianness

The convention describing the ordering of bytes in memory or the sequence 
in which bytes are transmitted.

external trigger

A voltage pulse from an external source that triggers an event such as 
A/D conversion.

FIFO

First-In First-Out—The first data stored in the memory buffer is the first 
data sent to the acceptor. FIFOs are used on IMAQ devices to temporarily 
store incoming data until that data can be retrieved.

function

A set of software instructions executed by a single line of code that may 
have input and/or output parameters and returns a value when executed.

gamma

The nonlinear change in the difference between the video signal’s 
brightness level and the voltage level needed to produce that brightness.

grab

Performs an acquisition that loops continually on one buffer. You obtain a 
copy of the acquisition buffer by grabbing a copy to a separate buffer that 
can be used for analysis.

hardware abstraction 
layer

Separates software API capabilities, such as general acquisition and control 
functions, from hardware-specific information.