Programming instructions

Chapter 21 Common SCXI Applications
© National Instruments Corporation 21-15 LabVIEW Data Acquisition Basics Manual
Figure 21-8.
Measuring Pressure Using Information from the DAQ Channel Wizard
Figure 21-8 continually acquires data until an error occurs or you stop the
VI from executing. In order to perform continuous acquisition, you need to
set up a buffer. In this example, the buffer is 10 times the number of points
acquired for each channel. After your device averages the voltage data from
the AI Read VI, it converts the voltage values to strain values. After
completing the acquisition, remember to always clear the acquisition by
using the AI Clear VI.
When measuring strain gauge data, there are some parameters on the
Convert Strain Gauge Reading VI, shown in Figure 21-9, you should know.
Figure 21-9.
Convert Strain Gauge Reading VI
Vsg
, the strain gauge value, is the only parameter wired in the previous
VI diagram. The other parameters for this VI have default values but those
values may not be correct for your strain gauge. You should check the
following parameters:
Vinit
, the voltage across the strain gauge before