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Chapter 2 Function Reference — WFM_Op
NI-DAQ FRM for PC Compatibles 2-434
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National Instruments Corporation
WFM_Op
Format
status = WFM_Op (deviceNumber, numChans, chanVect, buffer, count, iterations, rate)
Purpose
Assigns a waveform buffer to one or more analog output channels, selects the rate and the
number of times the data in the buffer is to be generated, and starts the generation. If the
number of buffer generations is finite,
WFM_Op waits for completion before returning, unless
you call
Timeout_Config.
Parameters
Input
Parameter Discussion
numChans indicates the number of analog output channels specified in the array chanVect.
chanVect is the array of channel numbers indicating which analog output channels are to
receive output data from the buffer.
Channel number range:
0 or 1 for most devices.
0 through 5 for AT-AO-6.
0 through 9 for AT-AO-10.
buffer is an array of integer values that DACs convert to voltages. If your device has 12-bit
DACs, these data will range from 0 to 4,095 in unipolar mode and from –2,048 to 2,047 in
bipolar mode. If your device has 16-bit DACs, data will range from 0 to 65,535 in unipolar
mode and from –32,768 to +32,767 in bipolar mode.
Name Type Description
deviceNumber i16 assigned by configuration utility
numChans i16 number of analog output channels
chanVect [i16] channel numbers
buffer [i16] values that are converted to voltages by DACs
count u32 number of points in the buffer
iterations u32 number of times the waveform generation steps
through buffer
rate f64 desired rate in pts/s