Using DAQ-assist to input a waveform; need help building a counter to count voltage "spikes"

Hey all! I'm pretty new to labView and even newer to this forum, but its nice to meet you all...I hope that perhaps someone can help me with my problem.
Allow me to begin by detailing the specifications of the problem. I am an undergraduate student, and have a job doing research in a MEMS (micro/nanotech) lab. The graduate student I am making this program for is working on biomedical applications; eventually, the program will be connected to a microdevice that has a tiny channel in it, cut through a wee little capacitor, which blood will run through. As red blood cells pass this capacitor, the voltage will spike; meaning that for each voltage spike, we can (and are trying to) count the number of red blood cells.
However, I am still in the early developement of the program, so this above specific info is not that important. Basically, I am using a function generator to input a waveform to the DAQ assistant of, say 500 mV. I am trying to write a program that increments a counter every time I turn the voltage above say 550 mV (peak-to-peak), counting the number of simulated "spikes." I have tried quite a lot to write a working program, and although I have not gotten it to work yet, I will post a screenshot of my most recent attempt HERE:
I thank you in advance for any helpful tips, advice, or straight up assistance you may be able to give me. Please ask me any clarifying questions about the program I wrote or the application, or anything. Happy Friday!

Hey guys, it's been a while! A lot of stuff has been happening in my life and I have had virtually no time to work on my LabView project.
I did create a LabView program based off IanW's reccomendation. I am unsure of what exactly is going wrong, but when I run it, only a simple "snapshot" of a waveform from the DAQ shows up in the graph. Even when I put the DAQ assist in a seperate while loop, the same thing happens. I am including a screenshot of the project in case I am messing something entirely different up. If you happen to read this, I really appreciate your help and thank you Ian!
I am also having a random issue with the filter signal VI. So that background signals in the actual experiment do not read as "spikes" I have been instructed to include a high-pass filter in the VI. However, everytime I use the high pass filter VI, it botches my signal and turns it into a bunch of noise! I, nor my graduate mentor (who isn't too well-versed in LabView) have any idea why this is - we've tried using different types of filters to no avail.
Lastly, I would like to talk to Peter about a few questions I had abour LabView design. In case you're still around, I will write another post later today with more detail. In the meantime, I will try to find some of the example VIs about shift registers All who read this have a great day!
Attachments:
count spikes pic.png ‏29 KB

Similar Messages

Getting the data in file using DAQ assistant in Labview

I am using SCXI 1000 chassis, SCXI 1125 input module and SCXI 1320
terminal.
I am using DAQ assistant in labview to obtain temperatures and store it in
a file. The experiments run the whole day and I need the whole data
generated during this time to be stored in a single file, but I am unable
to store it in a single file.
Can someone please give me some insight as to how can I achieve this?

Hi Mr,
It would be helpful to see your code to see exactly how you are acquiring the data. Are you doing continuous buffered measurements? Or are you performing single point temperature measurements in a while loop?
Either way you will want to use the "write to spreadsheet" VI in your loop. Simply wire your data into the "write to spreadsheet" vi and se the "append to file" input to TRUE. This will make the data add on to the end of the file with each iteration of the loop. The "write to spreadsheet" VI is located in the file IO pallette in LabVIEW.
Thanks,
Sal

New project using Daq Assistant or not ?

Hi everybody,
I need to create a software to do some realtime acquisition & analysis.
I trained myself a little bit on c# lessons to get use to this programming language; I’m also discovering Measurement Studio & Visual Studio. (I’ve background in C++).
My software will have 2 modes :
Continuous acquisition, signal plotting + signal processing & plotting (fft, 1/3 octave band filter)
Triggered acquisition, signal plotting + signal processing & plotting (fft, , 1/3 octave band filter)
I have examples in my National Instruments directory which don't use daq Assistant and code is different from generated files with daq Component.
If I use Daq Assistant ( http://www.ni.com/tutorial/4652/en/ )
I know that the code to create channel is stored in DaqTask.cs
Plotting :
NationalInstruments.AnalogWaveform<double>[] acquiredData = daqTaskComponent1.Read();
waveformGraph1.PlotWaveforms(acquiredData);
When I look to examples, like "MStudioVS2010\DotNET\Examples\DAQmxWithUI\SpectrumAnalyzer\cs "
all code to create channel is generated in Mainform.cs, there is no Daq Assistant (http://www.ni.com/tutorial/5409/en/ )
and there is a slight difference between acquired type :
private AnalogWaveform<double> data = new AnalogWaveform<double>(1000);
data = reader.EndReadWaveform(ar);
acquiredDataWaveformGraph.PlotWaveform(data);
Questions :
What is the difference between AnalogWaveform<double> and AnalogWaveform<double>[] ? why it's not the same type ? I need to do some signal processing with this signal, so what type should I use for my application ?
I didn't succeed to configure my 2 modes in daq Assistant (continuous and triggered acquisition) is it possible or should I create 2 Items in my solution, one for continuous acquisition and on for triggered acquisition ?
Kind regards,

Check out the downloads section of iLounge.com. There are a handful or two of applications that will help you transfer songs from the iPod to the computer.
Another option is to network the two computers together and transfer the iTunes folder to the new Mac. All you need is an ethernet cable and to turn on file sharing in the Sharing preference panel. Depending on how old your "older" Mac is, you might need a crossover ethernet cable.
A third option is to hook up the two computers using a Firewire cable. On the older Mac make sure it is shut down, hook the two computers up, turn on the older Mac while holding down the "T" key. On the new Mac you should see the old Mac's hard drive show up. Just find the iTunes music folder and copy it over. You could also use the Migration Assistant which will be in the Utilities folder of the new Mac.
Hope this helps.

How to use DAQ Assistant to display two analog channels in a XY Graph

Hi,
I am new to LabVIEW. I have been assigned a project in which i have to display two analog signals from an analog potentiostat i.e. voltage and current (also a voltage signal) on a graph using labview. I am using a myDAQ device to acquire these analog signals and I am using labview 2013 to display these signals on a graph. I am using DAQ assistant to configure these signals. Rightnow I have separate graphs for each channel. However, I want a single XY graph to display one voltage as a function of the other i.e. I want to have voltage on the X-axis and current output on the Y axis. Any kind of help is greatly appreciated.
I have attached a screenshot of the VI. that I have made.
Regards,
Max
Attachments:
New Microsoft Word Document (2).docx ‏32 KB

Thanks for the quick response. I was able to make a X-Y graph. However, I can only see a dot floating around. It's not drawing anything. I want to see it making a plot as it collects data. Also, I want to see the complete waveform formed when I stop the VI.
Thanks,
Max

Acquiring pressure data using daq assist

Hi all,
I want to use DAQ Assist to measure the pressure.When i select DAQ Assist>Acquire Signals>Analogue Input>Pressure>Pressure(Bridge) then is says 'no supported devices found'
What should i do?
thanks

I have Trafag pressure sensor anyway i give up doing it by daq assistant.I did it by using another daq tools.But now i have a new problem in calibration of sensor so i will post a new question

When using DAQ assistant to read frequency

When using DAQ assistant to read frequency and Task timing is set to:
N Samples, Clock settings to read 26,
Frequency setup to rising edge,
1 counter with 10 kHz to 1 kHz range.
I get back a single number.
Can I assume this is an average reading of 25 samples with the first sample unused?
What is the base clock used?
Is the “26” 26 cycles of the frequency to be measured?

Hello,
If you choose to acquire N samples from the DAQ Assistant then it will acquire all of these samples and return them to LabVIEW as an array. However, when you use the DAQ Assistant it outputs the data in the dynamic data type first. This data type makes it easy to graph and run the data through other express VIs. If you were to create a Numeric Indicator from this data type it would just display the last element from the dynamic data array. To display this data properly in a numeric format convert the dynamic data to an array of doubles by using the Convert From Dynamic Data function in LabVIEW. Then you can select to convert it to a 1D array of scalars and when you create an indicator off of the output of this function all of the data should be displayed.
The timebase that is used for lower frequency measurements is the onboard clock, which is internally connected to the Source. Then you connect your signal to be measured to the Gate of the counter. Since the frequency of the onboard clock is known it can be used to calculate the frequency of an unknown source based on when the counter is on and off (determined by the Gate).
Have a good day,
Brian P.
Applications Engineer

Can't use Daq Assistant in Labview 7.1

hi! I have Labview 7.1 installed and an AT-MIO-16E-10 NI board. I can see the board in MAX\devices&Interfaces\traditional NI-DAQ but i can't run any tests(Test panels). I don't know if this is normal for this NI-DAQ model. anyway my main conceirn is that i can not use DAQ Assistant in LabView(when i double click on it or right click->Properties nothing happends). So i can't use my board in LabView. please help! thanks a lot

You can use your board in LabVIEW but you can't use it with DAQmx. In the DAQ Quick Start Guide, the supported devices are listed and the AT E series is only supported with traditional DAQ.

I am trying to log data from 4 voltage input signal using labview, but when i use DAQ assistant i am able to log data from one signal at a time only.

I am trying to log data from 4 voltage input signal using labview, but when i use DAQ assiatant i am able to log data from one signal at a time only.I am trying to get all 4 input data to logged in a single file againt time. I am new to Labview, I need to sample this data within a couple of days can someone help please.

Naveen
Check out the info in the Analog Input section of the document linked below. (Ignore the part about Global Channels.) In Figure 5, notice that you can select multiple channels while holding <Ctrl> or <Shift>.
Developer Zone Tutorial: NI-DAQmx Express VI Tutorial
Kyle B | Product Support Engineer | ni.com/support

How do I use DAQ Assistant to output DC on an AO?

My background includes 15 years of programming PLC's. AO's were simple. You passed the AO a value between preset ranges and it output a proportional voltage signal based on the hardware capabilities.
I foolishly thought LabView and DAQ AO's would be about the same. I built a vi to generate a DC signal which I could control the amplitude of. I also tied it to a chart to monitor how it worked. I managed to draw some very pretty ramping pictures on my chart, but when I put a DMM across the physical terminals I see no voltage.
Then I used MAX to test the channel and measured it again. Now I see voltage on my DMM. I was attempting to use the DAQ Assistant to do this. Do I need to force it to re-read the changing value I am sending it? All of the examples I find show me more primitive methods, and I could not seem to get any of them to do what I want either. I need to send a speed reference to a DC drive.
My incorrect method was to recursively add a value for ramping the signal up or subtract to ramp down. This method works perfectly on an industrial PLC. I connected a chart to the signal just as it entered the DAQ Assistant, but the only way I could check the actual was with the DMM.
Are there any examples that use the Assistant? If not then I guess I will have figure out how to use the primitives anyway.
technomage

Hello technomage,
It looks like we have discussed this problem in another thread (found here). If you have any other questions about it, please post there.
Regards,
Jesse O.
Applications Engineering
National Instruments
Jesse O. | National Instruments R&D

I need to update Firefox, using Linux, but not a technie, so need help in step form please. Thanks

I am using Suse Linux - am trying to upgrade Firefox to the latest version. I am not a techie so need help step by step. Thanks so much

From http://suseroot.com/terms.php?term=Terminal
To open a terminal, go to the KMenu -> System -> Terminal -> (pick one). The "Super User" terminal lets you operate as root. This is also possible from the others with a "su" command.
Familiarise yourself by using the [http://www.novell.com/documentation/opensuse110/ PDF documentation] when seeking answers, or just use google like I did to find the above.

Im using iPad2, 16GB. stuck in recovery mode. need help.

Hi. Im using iPad2. stuck in recovery mode, tried getting out but cant. need help badly.

RECOVERY MODE
1. Turn off iPad
2. Turn on computer and launch iTunes (make sure you have the latest version of iTune)
3. Plug USB cable into computer's USB port
4. Hold Home button down and plug the other end of cable into docking port.
DO NOT RELEASE BUTTON until you see picture of iTunes and plug
5. Release Home button.
ON COMPUTER
6. iTunes has detected iPad in recovery mode. You must restore this iPad before it can be used with iTunes.
7. Select "Restore iPad"...
Note:
1. Data will be lost if you do not have backup
2. You must follow step 1 to step 4 VERY CLOSELY.
3. Repeat the process if necessary.

HP Envy 110e printer (D411a) will not install with me using Windows 8 Consumer Preview. I need help

Just pick up the new HP Envy D411a printer, i set up with my wi-fi and all was going well until i put the disk in my PC . Just to find out that my NEW printer will not work with the Windows 8 Consumer Preview . I need help with this or until UP update the new printer to work with Windows 8, which will be on the market soon. Can some one please HELP ME

Available now is print and scan capability that HP worked with Microsoft to include into Windows 8.
The Printer Install Wizard can provide you additional information:
http://h30434.www3.hp.com/t5/Windows-8-Consumer-Preview/How-to-Get-Your-Inkjet-Printer-Working-with-...
If I have helped you solve your issue please mark it as solved .....
(I am an HP employee)

I need a solution for the security questions please ?? In the other hand i can't use the rescue email !! I need help .

I need help for those security questions please !! I don't have a rescue email and even i don't know how to add it ! Please help me

I didn't mean to give me an answer for the security questions i mean that i didn't remember the answers and i don't have a rescue email to send in it , i'm just ask for sloution to reset my security questions got it?

Need help incorporating the second counter into a current data acquisition routine (continuous retriggerable AI).

My current application acquires data when it sees a TTL trigger line. Then it wait until the next TTL pulse and continues taking data until the user stop the data acquisition process. I use "counter 0" as counter source. The program works well. However I need to read digital data everytime I take AI data. I plan to use "counter 1" to read the digital data. The trick is that I need to synchronize both AI and counter 1 readings. Therefore the counter 2 will acquire data when AI acquires data.
Here is the code I implemented and would like to know if it is correct. The new code (implementation of second counter) is in the bottom part of the code. I will really appreciate your help.
Yajai
Attachments:
code.txt ‏6 KB

Hi DrObb,
What is sounds like you want to do is to specify an external sample clock for your analog acquisition and a digital acquisition. Is there a reason in particular that you're using a counter? What hardware are you using? If you simply want to sample a digital and analog channel on the same clock edge, this won't be very difficult (provided your hardware supports hardware-timed digital IO). You can find an example of this being done in C by going to:
Start » All Programs » National Instruments » NI-DAQ » Text-Based Code Support » ANSI C Examples and then navigating to Synchronization\Multi-Function\ContAI-Read Dig Chan
Regards,
Sean
Sean Ferguson
Application Engineering Specialist | RF and Reconfigurable Test

Need HELP building a website in Flash CS6

Hi,
I need help creating buttons within buttons with interactive capablility and separate timlines. The parent button on rollover will display the child button. The Child button on down state must be able to display a table that has links to images and other content. I'm a designer not a coder and I believe that this effort will require a lot of code.
Below is an image of the navigation. The small squares are the parent buttons. The text that is displayed on rollover is the child button. Once the text button is clicked a table will animate out of the little orange square on the side and move off to the right displaying numerous images that are linked to other content. After the table displays it needs to have its own timeline. If the orange square is clicked again or if the user clicks on the white space the table will colapse and the orange square will retract to it's original up state. I hope that makes sense and I appreciate any feedback.

To get the kind of interaction and anoimation you identify you will need to use movieclip symbols instead of button symbols.

Using DAQ-assist to input a waveform; need help building a counter to count voltage "spikes"

Similar Messages

Maybe you are looking for