How to apply single sine or square wave

Now I used NI-FGEN and NI-Scope for bender element test, I want to now how to generate single sine or square wave (normally in NI-FGEN, I saw only continuous wave generation type).thanks you so much

If I understand your question correctly, it sounds like you would like to output one period of a sine wave or square wave and then just 0V DC. To do this you can use the niFgen_Basic_Arb_Sequence_Example. You will want your first sequence to be a sine (or square) wave and then the second sequence to be DC with an amplitude of 0V. You could replace the while loop in that example with a sequence structure with a wait in the structure to last just a bit longer than your sine wave. This will ensure that your sequence doesn't repeat.
I hope this helps answer your question.
Regards,
Doug K.
Application Engineering
National Instruments

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Can I generate sine and square waves with NI PCI-MIO-16XE-50 card??

Can I generate sine and square waves with NI PCI-MIO-16XE-50 card??
How Do I generate those signals?

Hello;
You certainly can do that. The way to go about that is to use one of the Analog Output channels your board have available.
If you are using Labview to program the board, you can find good examples at Search Examples->I/O Interfaces->Data Acquisition->Analog Output->Multiple Point (buffered) Analog Output.
If you are using other Software language to program the board, you can fing examples at C:\Program Files\National Instruments\NI-DAQ\example\VisualC\AO.
Hope this helps.
Filipe

How to generate multiple digital outputs (square waves delayed) at 50 kHz?

I would like to generate 3 digital outputs like the picture attached at 50 kHz. Using the "digital pattern generator (marching values).vi", I can generate 3 digital square wave but without the delay time. How can I do that?
I'm using the card PCI 6034E.
Thank you
Attachments:
digital outputs delayed.png ‏8 KB

Hi,
the digital pattern generator (marching values) only shifts the binary value of the first signal and sample to the next signal/sample.
Have you tried generating your waveforms via build waveform and use t0 terminal to change the lead delay?
In general, this DAQmx example could be helpful which you can modify to your needs.
DAQmx Write Digital Channel- External Clock: https://decibel.ni.com/content/docs/DOC-11142
Regards,
Thomas

How can be time implimenting in Square Wave Point By Point .vi

i want to use "Square Wave Point By Point .vi" but i can not understand how to put time value.

Hello,
I understand you wanted to use the mentioned vi. So the thing is the inputs that you can see are not compulsory or required inputs. Those are recommended inputs which you can use if you have a requirement in your application. So in thise vi as you know the duty cycle will define the time a square wave remains high versus low over one period. Morever the output of the square wave will be as follows:
square wave = amplitude × square (p)
where
square(p) = 1 if [ (360. frequency. time + phase)mod(360)] is < [360. duty cycle(100%) / 100]
and -1 for other cases.
So from this equation you can work on your application and decide if you need any time input at all or not.
Hope this helps.
Cheers..!!

How to generate a high freq square wave on NI-USB 62xx

Hi,
I am trying to generate a 50khz square wave with an AO channel on the NI-USB 6212 (rated at 250ks/s AO). I started with the Voltage - Continuous Output.vi example but when i go up toward 50khz square wave (100khz sample rate) the edges of the square wave become rounded. The slew rate for the card is 5V/us and my amplitude is just .5V so i feel like I'm doing something wrong with the task setup.
I also tried setting continuous samples using the onboard clock for a source and then writing an array [1,-1] but that fails at anything higher than ~8khz.
What's the most efficienct/correct way to set up a task like this? Any help appreciated. Thanks.
Matt

Hello Matt,
Right now, I think that shape of the signal that is being output is being controlled by the load on the AO.
If there is a very large impedance load attached between AO and ground, the RC time constant of the circuit is going to be very high. This will result in a large amount of time required to charge and dissipate the voltage. By increasing the frequency, the amount of time allotted for this is being reduced. Potentially resulting in the waveform you are seeing.
Can you please upload a picture of your waveform?
Can you please try to reduce the load on the AO? This can be done by disconnecting the current load and attaching a small resistor (50 Ohms should be good). Does this result in the correct waveform?
Regards,
Thomas C.
Applications Engineer
National Instruments

I want to apply single square or sine wave

Now I used NI-FGEN and NI-Scope for bender element test, I want to know how to generate single sine or square wave for input wave by using NI-GEN and how to recieve the sigle wave by NI-Scope(normally in NI-FGEN, I saw only continuous wave generation type).Is it possible to solve this problem by using only NI-FGEN and NI-Scope only ? (without LABVIEW). Thanks you so much

Hi,
Thanks for contacting National Instruments. The NI-FGEN and NI-SCOPE drivers do not only have to be programmed using LabVIEW. They can also be programmed using CVI, C, and Visual Basic.
If you don't want to do any programming and would rather just generate and acquire waveforms with basic functionality you can use the soft front panels (SFP). There is a NI-SCOPE SFP and a NI-FGEN SFP. These can be found by going to Start >> Programs >> National Instruments and choosing NI-SCOPE or NI-FGEN. You will see the SFPs in these directories. NI-FGEN SFP will allow you to generate both square and sine waves at different frequencies and amplitudes. NI-SCOPE will allow you to read in waveforms at various sampling rates.
Hope this helps!
Erick D
Appl
ications Engineer
National Instruments

How can i output a square wave from one of the digital lines of NI 9401

hello,
i m very much new to the LABVIEW environment and NI. please help me guys. i am using cDAQ 9172 and NI 9401 which i believe is a digital I/O device. i want a square wave of amplitude 4 to come out of it so that i can use that to control the speed of a DC motor by pulse width modulation technique by varying the duty cycle. how do i output a continuos square wave?
Thank tou for reading.
hoping for a reply at the earliest
Regards
ashutosh

The DIO ports on a MIO will not satisfy your needs (unless you move to LV RT).
They do not support buffered outputs.
Your update rate (how often you can set the port and clear it) is going to be limited by how fast (a-hem slow) windows will let you iterate,
and,
be non-determinstic.
You could use,
1) LV RT with the existing board, or
2) FieldPoint PWM module, or
3) Arbitrary waveform generators, or
4) HS DIO board, or
5) use the analog output of your baord where you que-up a 0 -5V waveform of the proper shape (i.e. make sure that the duty cylce fraction of the update values are high, the rest low).
This is just to get a PWM signal out.
Now there is another issue. Determinism. How often do you plan on reading your inputs and making a change to you
r PWM? If you plan on doing more often that 10/second, write your code to handle windows going out to la-la land when you expect it to be working.
Can you tell I like LV-RT.
I hope my ramblings have helped.
Ben
Ben Rayner
I am currently active on.. MainStream Preppers
Rayner's Ridge is under construction

Convert square wave to sinc wave

Can anyone please show me how to convert square wave to sinc wave?
Solved!
Go to Solution.

Use the wave generator funtions found in palette Signal Processing - Waveform Generation. There are sine and triangle waveform generating functions there. You can set the number of samples and sample rate such that it would generate a partial waveform. Then you use Get Waveform Components to get the Y values, concat the values, then use Build Waveform to build it back to a waveform. You will get a back to back output. In the following example, I used a sine and square wave because a sine and triangle were too close in appearance and you could not readily see the effect.
As Smercurio says, I don't think this is a very good representation of an EKG signal. That signal has P, QRS, and T waves. There is no sine wave. The waves are like triangle waves, so just put DC waveforms (0 amplitude square wave) ahead of and in between triangle waves for P, QRS, and T, followed by DC.
- tbob
Inventor of the WORM Global

How do I Fix DDS Generated Sine Wave That Produces a Periodic Square Wave?

Hello,
I'm an undergraduate researcher with almost no experience dealing with FPGA semantics and other National Instruments hardware in general. Part of my project revolves around creating a sine wave signal via the FPGA on an sbRIO-9632 that is output via the board's analog I/O pins, and I found it convenient to adapt the code provided by the National Instruments tutorials (http://zone.ni.com/devzone/cda/epd/p/id/6066) to have it run on an sbRIO FPGA. The problem I'm encountering right now is that the actual output I'm seeing is a square wave as opposed to the smooth sine wave that was expected, and I've exhausted all my ideas on possible ways to debug this issue. Can anyone please give me feedback if they've seen this problem before or offer other suggestions on fixing this?
I'm currently running LabVIEW 2009 with the appropriate real-time and FPGA modules on a 64-bit Windows 7 machine. Again, the hardware is an sbRIO-9632 complete with analog I/O. I appreciate it everyone!

I am also having this issue and have not been able to find a solution in the forums. I am somewhat of a rookie so pardon me if I seem ignorant in any way. I am working on a graduate project where I need to produce some sine waves and I am getting more of a square wave when I output it and measure on the scope. The program I am running is quite simple at the moment to attempt to discover any errors by process of elimination. I have the sine wave generator in a while loop outputting to an AO port. I am using the cRIO 9022 with the 9269 AO module. I will attach screen shots of my code and my oscope image
Attachments:
sine wave.jpg ‏76 KB
code for project.PNG ‏169 KB

How to send a SQUARE WAVE to PXI-6259 over the LAN

howcan I send a SQUARE WAVE to PXI-6259 over the LAN, is
there any example or link any one can send me , thanx in advance.

Dear HaI L,
I managed to send a test signal (sine wave) to the device by choosing
the test panel option and choosing Analog output. In the analog output
I could many channels to choose from. ai0, ai1.ai2 and ai3.
I did this by right clicking NI PXI-6259, in the NI DAQmx devices
located in the Devices and Interfaces and choosing test and saw it on
an Oscilloscope without using the NI DAQ OPC capabilities, and I cannot
understand this thing.
1)How can it be possible without making a NI DAQmx channel and Variable?
2) I cannot create any channels in the devices and interfaces located
in My system but I can create NI DAQmx Global Virtual channels easily
in Data neighbourhood in the remote system, Plz tell me why?
3) I want to create a program and choose a channel to send the
signal, can I choose the channel that i create in the remote
system device ? and if yes how can I choose this ?
Thanx in advance.
Sincerely,
Munir Afzal Bhatti.
Attachments:
max.jpg ‏2305 KB

Phase shift of a sine wave and a square wave

Hi,
I would like to simply compute the phase shift between a sinusoidal waveform and a square one. Between two sin-s I can compute, but I have no idea how to do that with a square waveform.
Thanks,
Ussr123

Hi there,
the easiest way is to use the ExpressVIs.
But you are only allowed to use the ExpressVI "Tone Measurements" if you have enough periods of the square wave, because it computes the phase with FFT.
An other possibility is to use the spectrum analyser VI as used in the attached exsample.
Greetz
Branni
Attachments:
Phaseshift_Sqr_Sin.vi ‏89 KB

Trasnmitting a single sine wave using USRP

how do i transmit and recieve a single sine wave using USRP...i would really appreciate it if someone posted that example
i already understand the blocks of the usrp...but do i need to modulate the sine wave signal or i will just send it..i am really confused
i hope that you may post the example

Hey Eldokch,
See step 4 in the following white paper:
http://www.ni.com/white-paper/13880/en/#toc4
It uses two examples packaged with the NI-USRP driver, "niUSRP EX Tx Continuous Async.vi" and "niUSRP EX Rx Continuous Async.vi".
-Jim B
Applications Engineer, National Instruments
CLD, CTD

I want to use the Function Generator VI to send command signals through the NI 7344 motion controller. This will be a closed loop servo valve system. I want to be able to change from say a square wave to a sine wave on the fly. Idea's?

I am going to run tests that require an actuator to move using various types of arbitrary waveforms such as sine or square. The NI 7344 is hooked to the UMI that is going through a driver for a servo valve. The loop is analog and it is closed. I have played with some of the examples but can't get it to work. I have used the function generator VI to generate a signal but I think I am using the wrong input VI to the motion control board. When I use what I have it moves the servo and then stops. It doesn't continually generate the signal.
I would love to use the controls on the function generator vi to control frequency and amplitude ect. Any help or pointer would be helpful. Thank you in advance.

Hello,
I'm not clear on exactly how you want to use the generated data but I'm assuming they will be used as your target points.
There's a built-in example for motion called 'One-Axis Contour Move.vi'. This example demonstrates how to provide your target points as 1-D array. All you need to do is to replace the input array with the output of the function generator. In order to have it run continuously, use a while loop. You can further program your application so that it'll change the waveform on the fly by monitoring the user interface but this might be little little tricky as you will need to reset the move and load the new generated points while keeping track of your current position.
I hope this helps. Let me know if you have further questions regarding this
application.
Best regards,
Yusuf C.
Applications Engineering
National Instruments

How can I output a square wave to control a stepper motor using 7332 controller?

I have the following system configuration for testing a linear actuator (LA):
LabView 7.1
NI FlexMotion 7332 Motion Controller
NI Flex DMM 4070
The LA is a stepper motor with Step and Direction of Rotation inputs, as well as some discrete I/O for Power Enable and other functions.
The LA specification only requires that I send a 50% Duty Cycle square wave signal with frequency less than 300 Hz to it in order to make it step. The LA has it's own power source. I only need the 7332 to generate the drive signal and the DOR signal to the LA. Using some of the example VI's, I can get the LA to work, but I will need to incorporate the functions in to a custom application.
How can I weed through the numerous advanced functions the 7332 offers and only generate a DOR signal and a step command at a user-defined frequency. How do I set up the controller for this?
Thanks

Hello,
All the VIs that you can use to create a pulse train and digital I/O from your motion controller are found in the "Analog & Digital I/O VIs" sub-palette in the "Flex Motion" palette. Use "Load PWM Duty Cycle" and "Configure PWM Output" VIs to create the square wave. Use the "Set I/O Port Direction", "Set I/O Port MOMO", and "Set I/O Port Polarity" VIs to create digital output. I hope you find this information useful. You can learn about the specifics of these VIs and their inputs/outputs in the NI-Motion VI Help.
Regards,
Aaron B.
National Instruments

How do you find the frequency of a small sample size and a square wave.

I am collecting data from ten 12v pulses that are seperated pretty uniformly. The pulses make a square wave. I need to know how to input this small sample size and find it frequency. I need this frequency to be output in a readable file. Im not very knowledgeable in labview so if you try and help me please be very descriptive.
I know i need some sort of trigger because of uknown wait times before the sensor will be triggored but other than that im pretty lost. Any help would be appreciated.

What have you tried so far? What parts are giving you trouble? Please be as specific as possible. Post the code you have written.
You ask about frequency measurement and then you are talking about triggering.
If you always have 10 pulses, just measure the time from the beginning of the first pulse to the beginning of the last pulse. The frequency is 10/time.
Break down the problem to smaller parts. Acquire the data. Measure the frequency. Save the result to a file. Get each part working separately, then put them together.
Lynn
Sorry about duplicate post. My internet connection is very slow today.
Message Edited by johnsold on 05-31-2010 12:05 PM

How to apply single sine or square wave

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