National Instruments SCXI -1125 用户手册

the data corresponds to a scanned channel for easier access by 
C applications. BASIC applications need not call 

SCAN_Demux

 to 

rearrange two-dimensional arrays since these arrays are accessed in 
column-major order. For more information regarding each acquisition 
function, refer to the Traditional NI-DAQ (Legacy) Function Reference 
Help installed by default in Start»Programs»National Instruments»

 

NI-DAQ.

After acquiring raw voltage data from the acquisition functions, most 
applications require adjustment by device calibration constants for 
accuracy, scaling measured voltage, analysis, and graphical display.

The SCXI-1125 has stored software calibration constants loaded on the 
module EEPROM that are used to achieve the absolute accuracy 
specifications. 

SCXI_Scale

 scales an array of binary data acquired from 

an SCXI channel to voltage using the stored software calibration constants 
when it scales the data. You must call 

SCAN_Demux

 before 

SCXI_Scale

 if 

you have multiple channels in the scan. For more information regarding 

SCXI_Scale

, refer to the Traditional NI-DAQ (Legacy) Function 

Reference Help installed by default in Start»Programs»National 
Instruments»NI-DAQ.

After you have adjusted the measurement by the appropriate calibration 
constants using 

SCXI_Scale

, you can use a function from the NI 

conversion library 

convert.h

 to convert a voltage or voltage buffer from 

a voltage to units of temperature or strain. NI-ADEs also provide many 
powerful analysis functions to perform digital filtering, harmonic analysis, 
averaging, and complex mathematics on measurements.

After performing scaling and analysis on the acquired data, you can display 
the measurements in several ways. You can use any built in GUI tools in 
your ADE. NI ADEs provide many graphical controls and indicators such 
as charts, graphs, gauges, slides, and plots that you can use to display 
the data. There is also a built in function, found in 

nidaqex.h

, called 

NIDAQPlotWaveform

 that you can use to generate a simple plot of the 

data.

Performing scanning operations in software depends on the ADE you are 
using. While using LabVIEW, or Visual Basic, all scanning operations are 
prepared in software by using an SCXI channel string as the input to the 
channel parameter in the analog input VI or function. These ADEs also