Welding System User Manual

Chapter 2 Function Reference — DAQ_Op
© 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
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.
Range: See Table B-1 in Appendix B, Analog Input Channel, Gain Settings, and
Voltage Calculation
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
SCXI_Set_Gain. Refer to Appendix B, Analog
Input Channel, Gain Settings, and Voltage Calculation, 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