National Instruments 321645c-01 用户手册
Chapter 2
Function Reference — DAQ_Op
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National Instruments Corporation
2-129
NI-DAQ FRM for PC Compatibles
DAQ_Op
Format
status = DAQ_Op (deviceNumber, chan, gain, buffer, count, sampleRate)
Purpose
Performs a synchronous, single-channel DAQ operation.
DAQ_Op
does not return until
NI-DAQ has acquired all the data or an acquisition error has occurred.
Parameters
Input
Output
Parameter Discussion
chan is the analog input channel number. If you are using SCXI, you must use the appropriate
analog input channel on the DAQ device that corresponds to the SCXI channel you want.
Select the SCXI channel using
analog input channel on the DAQ device that corresponds to the SCXI channel you want.
Select the SCXI channel using
SCXI_Single_Chan_Setup
before calling this function.
Refer to the NI-DAQ User Manual for PC Compatibles for more information on SCXI
channel assignments.
channel assignments.
Range:
gain is the gain setting to be used for that channel. This gain setting applies only to the DAQ
device; if you are using SCXI, you must establish any gain you want at the SCXI module by
setting jumpers on the module or by calling
device; if you are using SCXI, you must establish any gain you want at the SCXI module by
setting jumpers on the module or by calling
SCXI_Set_Gain
. Refer to Appendix B,
, for valid gain settings. If you use an
Name
Type
Description
deviceNumber
i16
assigned by configuration utility
chan
i16
analog input channel number
gain
i16
gain setting to be used
count
u32
number of samples to be acquired
sampleRate
f64
desired sample rate in units of pts/s
Name
Type
Description
buffer
[i16]
contains the acquired data