Programming instructions

Chapter 6 One-Stop Single-Point Acquisition
LabVIEW Data Acquisition Basics Manual 6-10
© National Instruments Corporation
your analog input by using a Wait (ms) or Wait Until Next ms Multiple
function together with the AI Single Scan VI in a while loop within your
control loop diagram. Set the wait time smaller than your control loop
interval (at least half as small). If the
scaled data
output array is not empty,
exit the polling loop passing out the
scaled data
array and execute the rest
of your control loop diagram. This method does not return data as soon as
the scan has been acquired, as in the example described previously, but
provides ample time for other VIs and loops to execute. This method is a
good technique for balancing the CPU load between several loops and VIs
running in parallel.
In the previously described techniques, if you are using software delays for
control loop speeds greater than 1 Hz turn the
Use Default Timer
option
off in the
Performance
dialog box in your LabVIEW Preferences. Turning
this off gives you approximately 1 ms software timer resolution, instead of
the default 55 ms timer resolution.
For more control examples, refer to the VIs located in
examples\daq\solution\control.llb
.