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3.3 acquiring data

You will now develop your VI to acquire the data that the ADC is sampling. The VI will acquire 1000 samples ata rate of 100,000 samples per second. Once the 1000 samples have been gathered, the data will be analyzed programmatically todetermine the peak-to-peak amplitude and the DC offset. The data set will be displayed on a graph, and will be written to ameasurement file that can be opened in Excel.

LabVIEW contains a useful set of functions for data acquisition known as DAQmx. DAQmx is NI’s driver configuration software for DAQ devices. We will use the DAQ Assistant function toopen communication with the DAQ hardware, read data from the device, and close communication.

5. On the block diagram, right click to bring up the Functions Palette. (Refer to Figure 4.) The FunctionsPalette contains all of the functions and structures that can be placed directly on the block diagram. Notice that the functions areorganized into sub-palettes by functionality.

Functions Palette

6. Click Measurement I/O>>NI-DAQmx>>DAQ Assist.

7. When you place the DAQ Assistant on the block diagram, a Create New…window will open as shown in Figure 5. This menu will guide you as you configure your software tocommunicate with your hardware.

Create New DAQ Assistant Window

8. Select Analog Input>>Voltage. DAQmx will scan the system for available hardware and present theoptions; as shown in Figure 6.

List of Physical Channels

9. Expand the cDAQ module that is labeled (SCXI-1520).

10. Select ai0, (the analog input channel that the function generator is connected to.)

11. Click Finish.

DAQ Assistant Configuration Window

12. The DAQ Assistant window should now open. Configure the DAQ Assistant as shown in Figure 7.

  • Set the input range from 5 to -5 volts.
  • Change the Terminal Configuration to Differential. (Differential assumes that the voltage is measured between twochannels, rather than referenced to a common ground.)
  • Set the Acquisition Mode to N Samples.
  • Change Samples to Read to 1000 and the Rate to 100,000.

13. When you click OK, LabVIEW will build a subVI according to your specifications.

3.4 amplitude measurement of data

Similar to the measurements made on the oscilloscope, LabVIEW programs can analyze characteristics of asignal.

14. Right click on the Block Diagram to bring up the Functions Palette. (Note that if you click on the FrontPanel you will bring up the Controls Palette, which has entirely different choices.)

15. Select Express>>Signal Analysis>>Tone. The Configure Tone Measurements dialog box will now open. The Tone Express VI will display values related tothe amplitude and frequency of the signal.

Configure Tone Measurements Box

16. Configure the dialog box as shown in Figure 8.

17. Select Amplitude and Frequency in the Single Tone Measurements box.

18. When you click OK, LabVIEW will build a subVI according to your specifications.

19. Place your cursor over the data output terminal on the DAQ Assistant icon. The cursor should change to awire spool. Click on the data terminal and connect the wire to the signals inputterminal on the Tone Measurements icon. This wirerepresents the data flow from the DAQ Assistant to the measurements subVI.

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
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Damian Reply
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Akash Reply
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s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
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Devang Reply
are you nano engineer ?
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That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
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Source:  OpenStax, Introduction to mechanical measurements. OpenStax CNX. Oct 18, 2006 Download for free at http://cnx.org/content/col10385/1.1
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