Справочник Пользователя для National Instruments 321645c-01
Chapter 2
Function Reference — Lab_ISCAN_Op
NI-DAQ FRM for PC Compatibles
2-266
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National Instruments Corporation
Lab_ISCAN_Op
Format
status = Lab_ISCAN_Op (deviceNumber, numChans, gain, buffer, count, sampleRate, scanRate,
finalScanOrder)
Purpose
Performs a synchronous, multiple-channel scanned data acquisition operation.
Lab_ISCAN_Op
does not return until NI-DAQ has acquired all the data or an acquisition error
has occurred (DAQCard-500/700 and 516, Lab and 1200 Series, and LPM devices only).
Parameters
Input
Output
Parameter Discussion
numChans is the number of channels to be scanned in a single scans sequence. The value of
this parameter also determines which channels NI-DAQ scans because these 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 analog input
channels on the DAQ device that corresponds to the SCXI channels you want. You should
select the SCXI scan list using
this parameter also determines which channels NI-DAQ scans because these 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 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 the
NI-DAQ User Manual for PC Compatibles for more information on SCXI channel
assignments.
assignments.
Name
Type
Description
deviceNumber
i16
assigned by configuration utility
numChans
i16
number of channels to be scanned
gain
i16
gain setting
count
u32
number of samples to be acquired
sampleRate
f64
desired sample rate in units of pts/s
scanRate
f64
desired scan rate in units of scans/s
Name
Type
Description
buffer
[i16]
contains the acquired data
finalScanOrder
[i16]
the scan channel order of the data