Generating double impulse signal

Hello everybody,
i'm about to
generate a function which acts as a double pusle signal in which
changing the time of each interval is possible
i can see the signal and the changes of the time interval on the wavediagram of the frontpanel
but the problem that i don't
get the expected signal at the digital output line17 from the DAQmx
actually there is no output at all from line17 however there is no error message in the code when i run the simulation
i chose another output as an alternative but still there is no
output signal too however i checked these outputs with another
code
to test them if they work or not and the answer was positive also
with the testpanel they react with the changes which means
that configurations of the DAQmx is right
in my code i changed the rate many times to be able to see signal on
the oscilliscope not only in µs but also in different dimentions of time
but still there is no output
all of this mean only i have something in the code which i don't know is the reason of not getting the output signal
i
send my code as an attachement may be you can try it
and tell me where is the reason for not getting
this siganl as an output signal ?????????????
i have labview version 7.1
my device is NI-PXI 6259, it has 32 bit port
thank you very much
Satrinay
Attachments:
Correlated_digital_output1.vi ‏143 KB

Hello,
I build a vi which creates a twinpuls. If you look into the SubVI Twinpulse_train_generate.vi you see how to generate such a twinpuls signal.
The structure of the puls is:
low ticks 1 --> high ticks 1 --> low ticks 2 --> high ticks 2.
The Puls width is: (1/rate)*(high ticks 1)
In the Zip file are:
1. Twinpulse_train.vi
2. _Utility.llb (Get Terminal Name with Device Präfix and DWDT Boolean Array to Digital)
3. Twinpulse_train_generate.vi
To start it use the Twinpulse_train.vi (build with LabVIEW 7.1)
regards
Fabian Kinzelmann (NI Germany)
Attachments:
Twinpulse.zip ‏89 KB

Similar Messages

How do I generate an Impulse signal?

Hello,
I'm relatively new to LabVIEW and I need to generate an impulse (Dirac Function) signal into DC motor. At the same time, I need to be able to modify the width of the impulse signal.
I am currently using LabVIEW 7.1.
Regards,
Jemuel Ong
National University of Singapore
Solved!
Go to Solution.

Thanks for replying!
I'm using a WinXP machine connected to PCI-6024E and AT-MIO-16E-10. The whole setup is supposed to drive a DC motor and I'm supposed to design an experiment to input an impulse signal to the system and get an impulse/step response. I have to be able to define the width of the impulse signal.
Regards,
Jemuel Ong
National University of Singapore

Why AlivePDF generate double header?

I'm trying to generate a simple table with alivePDF. This is my code:
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
                                        xmlns:mh="mh.components.*"
                                        layout="absolute" width="500" height="500">
          <mx:Script>
                    <![CDATA[
                              import mx.collections.ArrayCollection;
                              import org.alivepdf.colors.RGBColor;
                              import org.alivepdf.display.Display;
                              import org.alivepdf.drawing.Caps;
                              import org.alivepdf.fonts.FontFamily;
                              import org.alivepdf.fonts.Style;
                              import org.alivepdf.grid.Grid;
                              import org.alivepdf.images.ImageFormat;
                              import org.alivepdf.layout.Orientation;
                              import org.alivepdf.layout.Resize;
                              import org.alivepdf.layout.Size;
                              import org.alivepdf.layout.Unit;
                              import org.alivepdf.pages.Page;
                              import org.alivepdf.pdf.PDF;
                              import org.alivepdf.saving.Method;
                              import org.alivepdf.visibility.Visibility;
                              import org.alivepdf.grid.*;
                              import mx.utils.ObjectUtil;
                              private var myPDF:PDF;
protected function savePDF(e:MouseEvent):void
                                        var myPDF:PDF = new PDF ( Orientation.PORTRAIT, Unit.MM);
                                        myPDF.setDisplayMode(Display.FULL_PAGE);
                                        myPDF.addPage();
                                        var dp:ArrayCollection = new ArrayCollection();
                                        dp.addItem( { firstName : "Bob", lastName : "Groove", city : "Paris" } );
                                        dp.addItem( { firstName : "Bob", lastName : "Wise", city : "Paris" } );
                                        dp.addItem( { firstName : "Bob", lastName : "Wise", city : "Paris" } );
                                        dp.addItem( { firstName : "Bob", lastName : "Wise", city : "Paris" } );
                                        myPDF.textStyle ( new RGBColor ( 0x0EEFF0 ) );
                                        trace(ObjectUtil.toString(dp));
                                        var grid:Grid = new Grid ( dp.toArray(), 200, 100, new RGBColor (0x000000),null,false,null,null,0,12,6,"0j");
                                        myPDF.addGrid( grid, 5, 5);
                                        myPDF.save( Method.REMOTE, "coldfusion/pdf.cfm", "inline", "test.pdf" );
                    ]]>
          </mx:Script>
          <mx:VBox width="100%" height="100%">
                    <mx:HBox width="100%" backgroundColor="#FFFFFF">
                              <mx:Spacer width="100%"/>
                              <mx:Button horizontalCenter="0" label="SavePDF" height="22" click="savePDF(event)" id="savePDFBtn" toolTip="SAVE TO PDF"/>
                    </mx:HBox>
          </mx:VBox>
</mx:Application>
The problem is that this generate a double header and I don't know why. You can see a live example here: http://docs.google.com/viewer?url=http://prestitiinpdap.biz/pdf/myPDF.pdf
Could you help me solve this error?
Thanks

Many thanks, but the support seems discontinued also in the forum.
I got an answers on http://stackoverflow.com/questions/14799768/why-alivepdf-generate-double-table-header

I am trying to use generate code in signal express to import into labview.

I get this error when i try to generate code in signal express to export to labview . I have tries the error suggestions but I am still having problems. any help would be appreciated
The version of LabVIEW you are generating code into does not contain all the necessary SignalExpress support files. Make sure you launch the version of LabVIEW with SignalExpress support installed before generating code from SignalExpress. If you want to generate code into more than one version of LabVIEW, uninstall SignalExpress and all versions of LabVIEW except the earliest. Install SignalExpress, then install any other versions of LabVIEW. Copy the files from the vi.lib\express\SignalExpress directory of the earliest installed version of LabVIEW into the same sub-directory location of any other version of LabVIEW in which you want to include support for code generation.

Typically, this problem is repaired by following the directions on the error message. Since it was not, can you please give us more information so we can start determining the cause?
What version or versions of LabVIEW do you have installed? What version or versions of SignalExpress do you have installed? Could you post a file with a listing of the files in <vi.lib>\express\SignalExpress for the version of LabVIEW you are trying to use. You can either post a screenshot (in PNG or GIF format) of the directory dialog or use the command prompt to generate a list to a file (preferred). To generate a list with the command prompt, do the following:
Launch the command prompt from the start menu — Start»Programs»Accessories»Command Prompt
Navigate to the drive you have LabVIEW installed on ( usually C: ) — C:
Change directory to the appropriate LabVIEW directory — cd "\Program Files\National Instruments\LabVIEW 8.2\vi.lib\express\SignalExpress". Change the LabVIEW version to the one you actually are using. Do a directory listing and redirect the output to a file — dir > filename.txt. You can use any full path for the filename.txt. If you specify a simple name, it will end up in the current directory.
Please post your project. Verify that you are using the version of LabVIEW you think you are by launching it before you start code generation.
Thanks for your patience.
Message Edited by DFGray on 08-28-2008 08:23 AM
Message Edited by DFGray on 08-28-2008 08:24 AM
This account is no longer active. Contact ShadesOfGray for current posts and information.

Generating an input signal

I have completed the FPGA Module tutorial and I am attempting to generate an input signal, but i really don't understand exactly what is going on in the tutorial. I have two FPGA I/O nodes in the FPGA VI that are labeled "ADC 0 PORT A_I" and a corresponding one labeled Q as well. I'm assuming that these generate a sine wave that the tutorial used as the input signal. I want the input to be a sine wave with noise, and Mauricio suggested using DDS, but I don't know exactly how to add this to the existing FPGA VI that I created in the tutorial. Can anyone help me out on this one?

I'm a bit confused by your post. The FPGA Module tutorial guides you through the creation of a VI that acquires a signal. The I/O nodes labled "ADC 0 Port A I" and "ADC 0 Port A Q" are the I and Q elements of the acquired and downconverted signal. Just to be able to test this code, the HOST VI also configures one of the Analog Output channles in "Single Tone Mode" and therfore generates a sine through it. However, the FPGA is not doing anything to generate the sine tone, it's the DAC which is configured to generate the sine tone.
The I/O nodes that you need to use to generate signals are the "DAC 0 Data" and "DAC 0 TxEnabled". You will also need to use another clock, the "DAC 0 IQ Clk".You might want to read some documentation on the Analog Output and look at the IQ Output example. You can find the documentation on this post: http://forums.ni.com/ni/board/message?board.id=ifrio&message.id=140

How to continously generate a voltage signal with dynamic amplitude.

Hello all,
I am looking for ideas and pointers (help in other words). I would like to generate a voltage signal (sine for example) on a AO of my NI cRIO-9263 (DAQmx). The signal should be:
continuous (without jumps ie. smooth)
dynamically able to be change the amplitude, frequency and sampling rate.
interuptable so that the AO can be turned off.
I have tried to use the DAQ Assistant but once it runs in continous mode, I have the impression that the waveform should not be changed. Is there maybe a way where I send repeatedly N samples of the waveform to the AO and gain more control over the signal that way. But if I do that how can I ensure that the signal is continous?
Further more this output has to be generated in an event application ie. in the background.
Your ideas and input is appreciated. Thanks, Bernie

See if this example VI helps
Ches this one too

Generating frequency hopping signal

I'm working with 5661 + 5671.
I want to generate frequency hopping signal with 5671. The frequency band is 2400-2500MHz, and the hopping rate is one hop per frame (1.024ms) or 976 hop per second.
I also need to be able to test the hopping signal with 5661 RFSA.
Does it possible to run such hopping test with the 5661+5671?
Thanks,
Chen
Solved!
Go to Solution.

HI
I want to generate a hopping signal with PXI-5671 RFSG and want to analys with PXI-5660 RFSA. While seaching for the related posts i came across ur post, The frequency range in my case is between 200-300Mhz but i will use 200-220Mhz due to BW of 20Mhz...the hopping rate i wil use is very slow as compared to urs..i m trying to do this with 10-20 hops per second..
I m new with the hardware i have used it to generate and analyz the signals but stil unable to generate the hopping signal with predefined hopping sequence and hopping rate...
can you guide me that how to do this????or can u give me a copy of ur VI so that i can learn it from ur program and regenrate with my specs to chk weather it works or not...??
I wil b realy thankful if u can help me in anyway....
REGARDZ

Generating a digital signal

Hello,
I am trying to generate a digital signal which can be controlled in terms time i.e. Switching ON for 10 minis off for 5 minutes. I tried to generate a digital signal which is going high but unable to control it. As I am the beginner in labview any kind of help is appreciated.
Please see the attachment for the developed block diagram
Attachments:
digital signal generation.vi ‏17 KB

It appears that all you posted is one of the shipping examples. Is that all you've tried? You can't control it because you're not actually doing anything inside the loop. You're simply setting the value high before the loop starts, and not changing it in the loop. What kind of device do you have? Is it software controlled? If so, you will need to keep track of the time inside the loop. You can use the Elapsed Time VI to do this. Attached is a simple example to get you started to see how this can be done. I'm sure you can figure out how to integrate what you did and what I've shown you.
To learn more about LabVIEW it is recommended that you go through the introduction material, tutorial(s), and other material in the NI Developer Zone's Learning Center which provides links to other materials and other tutorials. You can also take the online courses for free.
Attachments:
Switching signal.vi ‏29 KB

Generating a flicker signal VI?

Hello all,
I'm currently creating a program which creates several tests concerning Power Quality with a Daqmx PXI-4461.
First of all i would like to say that i have no problem generating or reading signals with the Daqmx.
I'm currently at the point where I want to generate a flickering squarewave signal (flickering = small voltage dips over time) with the Daqmx, and was wondering if there was an example somewhere on the web that lets me insert the flickerfrequency and % decrease compared to the RMS value
Like a good professor of mine always said, its better to edit an excisting example then to start from scratch!
Regards,
Dennis

Hello Dennis
I didn't directly find directly usable code, but I did find something else:
https://decibel.ni.com/content/docs/DOC-12324
http://sine.ni.com/cs/app/doc/p/id/cs-13888
I think that especially the first document could help you a bit further.
Another thing you could try is contacting the author of the case study to request if he can send you his code.
Kind Regards,
Thierry C - Applications Engineering Specialist Northern European Region - National Instruments
CLD, CTA
If someone helped you, let them know. Mark as solved and/or give a kudo.

Whether could I generate one AC signal and acquire one DC signal and one AC signal together using NI myDAQ?

Dear Sir:
I would like to know whether I can generate one AC signal and acquire one DC signal and one AC signal together using NI myDAQ? If I can, could you please tell me the easiest way to achieve the goal? If I cannot, please tell me whether I can use both white box to do this because I have got another white box USB-6008. Cheers
Kind Regards
Jeff

duplicate post
Don't create a new thread. In the thread above, you asked for someone to review your code but you did not post a modified VI. Your original one is obviously wrong as I noted.

Generating Multiple Modulated Signals

I was a bit surprised I didn't see this on the forums, though I am new to the RF gear. What I would like to do is generate two modulated signals, such as 802.15, on two different frequencies. I am already able to create the signals individually using the modulation toolkit. I am using a PXI-5671 RFSG. I have found how to generate with interferance two CW tones in the examples, but do not see how to generate the two modulated tones. I also need to be able to set one of the modulated signals to a lower power than then other. I am trying to test adjacent channel interferance with modulated signals. Any thoughts?
Troy

Hi Troy,
There are a few tricks you can play here but
they are completely independent of hardware and more on signal
processing. Basically you need to write both waveforms at the same time
with different frequency offset.
1) Frequency Shift. Assume you
have two completelly independent baseband signals s1[n] and s2[n]. Each
one should be the same lenght (time duration).
One of them will
be transmitted at Fc and the other one at Fc + df. s1[n] remains
unchanged and s2[n] will be shifted by df using the following VI:
The
trick here is to make sure that your sample rate is high enough to
support the shifting, otherwise you will be aliasing. If you create
your waveforms with Modulation Toolkit make sure they have enough
samples per symbol.
Finally you need to sum all signals s[n] = s1[n] + s2[n].
2)
Apply different Powers. Before you add the signals, you only need to
scale the data correctly. To do this, I recommend to normalize both
waveforms. This is s1[n]/max(sqrt(|s1[n]|). Thenscale the smaller power
one. Finally, you will add them together.
Here is a spectrum of the composed signal:
I have attached
an example to do this using 802.15 signals with a few modifications: I
am not normalizing data but applying headroom to each signal and I
hardcoded the number of samples per symbol so the maximum frequency
offset is about 12 MHz. Should be helpful to get started.
Message Edited by Yardov on 10-17-2008 06:05 PM
Gerardo O.
RF Systems Engineering
National Instruments
Attachments:
frequency shift.jpg ‏9 KB
Generation Multiple Channels.zip ‏32 KB
spectrum.jpg ‏79 KB

How do I generate custom-made signals (impulses) from the parallel port

I am trying to generate some simple pulses to drive an external device. I am sure this is simple, but I'm not sure how to do it in LabView. I need to generate to TTL-level (2.4 - 5v) pulses that are spaced 500ms apart and occur every 34 seconds (that's the period).
Any suggestions?

ilogix-
The easiest way to write to the serial port in LabVIEW is with the Port Out.vi. You can find the help info here. You can find the address of the parallel port in the properties (located in Control Panel>>System>>Hardware Tab>>Device Manager) under the Resources tab. IT is the first number in the I/O range property (usually 0378).
This is a digital line and the parallel port is written as a byte so your labVIEW program will need to write a byte, delay and write another byte to get a "waveform".
Xaq

Recording quadrature encoder and AI signals simultaneously and generating output TTL signals in one VI

I want to record simultaneously encoder, pressure and other AI signals and output a TTL signal for every other pressure signal. I have two VIs: One is to record all signals and the other is to generate TTL signals.
1. Since I'm new to Labview, I would like to double check with experts that if my VI (attachment 1) did what I expect. I would like to have DAQ box read and write encoder signals and pressure signals at the same time so I can plot PV diagram.
2. During acquisition, some data points are usually missed, shown in attachment 2. Is there any way to solve it?
3. I tried to combine two VIs but it never work (attachment 3). Can anyone give me any suggestions?
PS. Labview 9.0 and NI USB-6216 are used.
Dummy signals are 30Hz sine waves for pressure and 2 TTL signals for encoder A and B at 5kHz.
Thank you!

Thank you for your help, Peter!
I attached the wrong file for attachment 1. The initial code for measurement is attached here.
The sampling rate is 20000 and the sample mode is continuous.
For missing data points, it improved when I add "wait until next ms multiple" in while loop.
Follow the example you gave me, I'm able to generate TTL signals in one vi, attachment 2. Could you please check if it's correct?
It looked fine with simulated signals and hope it will go well with real engine tests.
I have two more questions:
1. Does the input number for wait until next ms multiple should always be the same as "samples per channel" in sample clock?
2. How will the value of "samples per channel" in sample clock affect data acquisition? I tried 1000 and 10 but didn't see any difference between these two.
Thanks a lot.
Attachments:
recording VI.png ‏332 KB
AI+CI+CO.png ‏72 KB

NI9411 wrong frequency measurement of flow sensors / 24 impulse signals

Hello Ni Forum,
I already searched for similar problems, but haven't found anything helpful. So I'm posting our problem here. I'm apologizing in advance for bad english, it's not my mother tongue
We're encountering some strange behaviour of our NI9411 Module. We're using it in a Compact Rio with some other modules (2x Analog In).
Our goal is to measure the frequency of three flow sensors (impulse high = 24V, 0-22kHz) among with a torque sensor (TTL 5V, 30-60kHz) and a speed sensor (TTL 5V, 0-51,2kHz).
They are wired as follows:
DI0a = torque sensor
DI1a = flow sensor 1
DI2a = speed sensor channel A
DI3a = speed sensor channel B
DI4a = flow sensor 2
DI5a = flow sensor 3
Correspondig ports b are left unconnected, as it is said in the data sheet. All ground ports of sensors are connected to COM port of 9411. The module was connected to a 24V power supply.
Now the torque and speed sensor measurement works fine. But measuring the signals of the flow sensors seems to be difficult.
If an external frequency generator (impulse high about 9V, f=1,000kHz) is connected to port DI1a instead of the sensor signal, LabView shows exactly 1,000kHz. DI5a showed an avarage of 10 Hz, with a range from 10 to 60 Hz. DI4a equaled constant zero. The flickering up to 60Hz of DI5a was gone after disconnecting the 24V supply of the module. This changed nothing on the phenomenon described below.
If the signal high impulse voltage is raised, the measured signal frequency goes up to 1300 Hz @ 24V signal high impulse voltage. The signal additionally raises, if an oscilloscope is connected to DI1a, to 2180 Hz (range 2110 to 2240Hz). However, there is no change of frequency if the osci is connected to DI5a. With the 24V supply connected, DI5a showed a frequency up to 600Hz @ 24V signal high impulse voltage on DI1a, also rising when connecting the osci on DI1a. As mentioned, there was no frequency measured on DI5a after disconnecting the 24V power supply.
The signals of the generator showed some peaks on each edge (rising and falling) with values for example of 11V above high impuls voltage of 9V (20V together). That may causes that wrong frequency measurement.
The signals of the flow sensors do not have such peaks, the LabView-frequency nevertheless does not match the real frequency, as shown below (all values in Hz):
LabView
ideal values
Flow Sensor 1
Flow Sensor 2
Flow Sensor 1
Flow Sensor 2
4600
12200
740,6
6760,0
6400
13500
1481,3
7500,7
9700
16400
2962,6
8982,0
12900
19500
4443,8
10463,2
We're kind of helpless now. How can we get the signals of the flow sensors measured the right way? Are we doing something essentially wrong? Thanks in advance for offered help. I hope, I've given any necessary information. Any missing details will of course be delivered.
Puls-Measure-VI is attached beneath.
Regards,
Johannes Rost
Attachments:
vi.png ‏20 KB

Dear Lynn,
thank you for your reply. The impedance was an issue that our local technical distributor already suggested to check. According to the datasheet of the flow sensor (see attachement) it can drive a current of 25mA. The signal generator we used is a test generator that can be used instead of the flow sensors to check the any evaluation unit the sensor is connected with. So it should generate signals that are equal to those the sensor would have generated. And even with this the frequencies measured with LabVIEW are not as expected.
We are in contact with the sensor manufacturer to exclude mistakes in connection on the sensor side. But the behavior with the signal generator makes us think that is has to do something with the characteristics of the NI9411 that we don't know yet.
Attachments:
block diagram signal amplifier and signal description.png ‏151 KB
technical data.png ‏124 KB

How to generate an impulse to test the short circuit in an inductor

Hello,
Im new to labview and i'm in need to perform SURG - SURGE STRESS TEST
The purpose of this test is to detect an inter-turn short by applying a number of high
voltage impulses (or surges) to the selected winding.
Each impulse should produce a sinusoidal transient which eventually decays to zero.
How to generate impulse using labview.
Solved!
Go to Solution.

Hi Swathi,
Please see the function "impulse pattern.vi" in signal processing --> Signal generation pallettes.
Else you can browse through the examples in LabVIEW.
Regards,
Srikrishna.J

Generating double impulse signal

Similar Messages

Maybe you are looking for