National Instruments 321645c-01 用户手册

Chapter 2

Function Reference — Lab_ISCAN_to_Disk

NI-DAQ FRM for PC Compatibles

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 National Instruments Corporation

Performs a synchronous, multiple-channel scanned data acquisition operation and 
simultaneously saves the acquired data in a disk file. 

Lab_ISCAN_to_Disk

 does not return 

until NI-DAQ has acquired and saved all the data or an acquisition error has occurred 
(DAQCard-500/700 and 516, Lab and 1200 Series, and LPM devices only).

numChans is the number of channels to be scanned in a single scan sequence. The value of 
this parameter also determines which channels NI-DAQ scans because these supported 
devices have a fixed scanning order. The scanned channels range from numChans – 1 to 
channel 0. If you are using SCXI modules with additional multiplexers, you must scan the 
appropriate analog input channels on the DAQ device that corresponds to the SCXI channels 
you want. You should select the SCXI scan list using 

SCXI_SCAN_Setup

 before you call this 

function. Refer to Chapter 12, SCXI Hardware, in the DAQ Hardware Overview Guide and 
the NI-DAQ User Manual for PC Compatibles for more information on SCXI channel 
assignments.

Range:

1 through 4 for the 516 and Lab and 1200 Series devices in differential mode.
1 through 8 for the DAQCard-500 (single-ended mode only).

i16

assigned by configuration utility

i16

number of channels to be scanned

i16

gain setting

STR

name of the data file to be created

u32

number of samples to be acquired

f64

desired sample rate in units of pts/s

f64

desired scan rate in units of pts/s

i16

enables concatenation of data to an existing file