Objective: Develop a basic understanding of the
National Instruments PCI-6025E data acquisition card and LabVIEW data
acquisition and control software.
Part 1: LabVIEW Tutorial
- Work through chapters 1,2,3,5 of the LabVIEW QuickStart Guide
including the LabVIEW tutorial.
- Show me the random number generator and plot created at the end
of chapter 2. Learn how to change the background color of the
plot to white - this will be useful when we need to print plots
so that they are easily viewed.
- In chapter 3, use function generator to generate voltage signal
for the temperature example and view the voltage by choosing
Bench-Top Instruments -> One Channel Oscilloscope rather than
Data Logging within the Solutions Gallery.
- Show me the analog input from the function generator and plot
created at the end of chapter 3. Change the background color
of the plot to white to print this plot for your write-up.
Part 2: Hardware-Timed Loops
- Control and data processing are most easily accomplished when
sampling and control actions occur at precise intervals of time.
Recall from EE342 that a fixed time between samples was assumed
for our discrete-time signal analysis and that control strategies often
involve integrals and derivatives of signals that are more easily
computed if signal samples and updates are equal time intervals
apart. One method of timing loops is via hardware timing in
LabVIEW.
- When starting a new LabVIEW task, it is often useful to look at
the extensive examples shipped with LabVIEW that are found by
selecting Search Examples on the main LabVIEW window.
For our hardware-timed data collection, we'll start with an
example found in Data Acquisition (DAQ) under
Simultaneous Analog I/O in the example entitled
Analog I/O Control Loop (hardware-timed). Select this
example VI and save it to your working directory.
- Look over this VI carefully and then remove the analog out
related components leaving only analog input and plotting.
- Run your modified VI and sample one signal on one channel
from the function generator.
- Show me the resulting plot, change its background
to white, and print it for your write up.
- Print your VI diagram and write a brief description of what
everything in the diagram is and does.
Additional Questions:
- The PCI6025E DAQ card has analog inputs that can be configured
in reference single ended or differential mode. What is the difference
between these two modes of analog input? How many analog signals
can we sample if all are configured either single ended or
differential?
- What are the advantages of using a hardware-timed loop for
signal sampling versus a regular loop?
- What is the pin configuration of the DAQ card ribbon cable
connectors?
- What is the difference between a LabVIEW front panel and
block diagram?