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Chapter 2 Function Reference — DAQ_DB_HalfReady
NI-DAQ FRM for PC Compatibles 2-122
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National Instruments Corporation
DAQ_DB_HalfReady
Format
status = DAQ_DB_HalfReady (deviceNumber, halfReady, daqStopped)
Purpose
Checks whether the next half buffer of data is available during a double-buffered data
acquisition. You can use
DAQ_DB_HalfReady to avoid the waiting period that can occur
because the double-buffered transfer function (
DAQ_DB_Transfer) waits until the data is
ready before retrieving and returning it.
Parameters
Input
Output
Parameter Discussion
halfReady indicates whether the next half buffer of data is available. When halfReady
equals 1, you can use
DAQ_DB_Transfer to retrieve the data immediately. When halfReady
equals 0, the data is not yet available.
daqstopped returns an indication of whether the data acquisition has completed.
If daqstopped = 1, the DAQ operation is complete (or halted due to an error). If
daqstopped = 0, the DAQ operation is still running.
Note
C Programmers—halfReady and daqStopped are pass-by-reference parameters.
Name Type Description
deviceNumber i16 assigned by configuration utility
Name Type Description
halfReady i16 whether the next half buffer of data is available
daqStopped i16 whether the data acquisition has completed