FPGA wave generator precision

Hello,
I am trying to implement a FPGA project that requires signal frequency precision levels of about 1 mHz. Due to the data types in the project, I seem to be having difficulty adjusting the frequencies of the Labview FPGA sine and square wave generators by 1 mHz; the specified frequencies (for example, 999.998 Hz) get binned to the closest available number (for example, 999.996 Hz). I would like to change frequencies by only 1 mHz. Is this possible with an FPGA project? Any help would be much appreciated.

did you check out http://zone.ni.com/devzone/cda/epd/p/id/6066
notice figure 9 for computation of accumulator increment. how are you trying to solve it? what hardware?
Stu McFarlane
Viewpoint Systems, Inc.

Similar Messages

LabVIEW FPGA Sine Wave Generator Reset Input Behavior

I would like to know what the output from the Sine Wave Generator express VI is while the reset input is true, and what happens to the output immediately after the reset input is set false.
I need to generate a regular sequence of positive half-cycles of a sine wave, with an arbitrary delay between them that is not related to the actual frequency of the sine wave. So my plan is basically to periodically fire a trigger in the fpga software that resets a sine wave generator and directs its output to an analog output until the sine wave goes negative, at which point the analog output is set to 0 until the next trigger.
Thanks

Muchas gracias por responder steve.bm
El problema que tengo es el siguiente, estoy desarrollando un proyecto en el cual uso los conversores DAC y ADC de la tarjeta FPGA Spartan 3E para lo cual use como base el proyecto que esta subido por la NI que se encuentra en uno de los enlaces que me dejaste,( Lesson 8 - Linking Existing VHDL Code from WebPACK into LabVIEW FPGA) del mismo solo modifique para usar el ADC y el DAC mediante el cual adquiero una señal senosoidal y la tengo que reconstruir, el problema es que como uso un generador de señal de laboratorio al ingresar la frecuencia de muestreo para obtener una buena reconstruccion, la frecuencia se baja lo cual en el proyecto real no podra pasar ya que la frecuencia ya en proyecto final la adquiero de la red electrica publica pero ahora para pruebas estoy con un generador, la verdad no se que pasa porque tiene un retrazo la señal.....
Te parece si te puedo dejar mi proyecto subido en enlace para que lo revices ??

FPGA sine wave generator

NI工程師你好
我在FPGA端使用sine wave generator
可是出來的波形卻不是一個完整的Sin波圖形
可以請工程師幫我解答一下嗎??
已解決！
轉到解決方案。
附件:
sin.png ‏10 KB
sin-1.png ‏13 KB

好吧，我認為問題可能是您使用的圖表上的FPGA。不幸的是，LabVIEW的通信方式，有時會導致與 FPGA圖表更新不當，因為他們目前沒有時間同步的時間在芯片上。我組建了一個簡單的應用程序，而不是傳輸分回的主機和波形似乎是正確的。讓我知道這是否有助於。
附件:
Sine.zip ‏317 KB

Générer une implusion avec "Sine Wave Generator" en FPGA

Bonjour,
Content de vous rejoindre sur ce forum. Tout nouveau en Labview (pas très à l'aise avec certaines notions), je voudrai soliciter votre aide. En fait, je veux créer une impulsion de 100Hz avec la fonction " Sine Wave Generator" de FPGA. En simulation j'ai réussi mais dès que je compile en target il m'affiche ce message : "Top-level clock rate does not match rate for which the Sine Wave Generator VI was configured. Reconfigure the Sine Wave Generator or the top-level clock so that their rates match. You also might need to modify computed values for the frequency (cycles/tick) input."
Je change donc FPGA clock rate et je choisis 40MHz (la seule qu'il me propose). Mais dans ce cas, je me perds pour retouver mon impulsion (qui doit durer une période 0.01sec). J'ai essayé de jouer sur le nombre d'échantillons en changeant le nombre d'itérations de la boucle For afin de générer toujours une période ( pièces jointes) mais ça marche pas!!!
Pourriez vous m'aider à déchiffrer ce problème?
Merci d'avance
Pièces jointes :
burst sine.png ‏372 KB
burst sine_40MHz.png ‏336 KB

Bonjour M2IM,
En mode simulation, on utilise une fonctionnalité appelée "Interactive Execution" car l'exeuction/affichage ne peut être géré à une fréquence élévé (40 MHz dans le cas de la Top Level Clock par défaut).
En mode FPGA target, la vitesse est plus élevé et donc uniquement certains points du sinus seront afficher mais le signal electrique lui sera bien un sinus.
Je t'invite à regarder le lien ci-dessous qui reprend quasiment la problématique que tu rencontres:
Generate a sine with LabView FPGA and connect it to an AOModule
Bonne journée,
Valentin
Certified TestStand Architect
Certified LabVIEW Developer
National Instruments France
#adMrkt{text-align: center;font-size:11px; font-weight: bold;} #adMrkt a {text-decoration: none;} #adMrkt a:hover{font-size: 9px;} #adMrkt a span{display: none;} #adMrkt a:hover span{display: block;}
Travaux Pratiques d'initiation à LabVIEW et à la mesure
Du 2 au 23 octobre, partout en France

FPGA sine generator

NI 工程師您好： FPGA Sine Generator中的 Look-Up table size 是指什麼? 如果While loop的迴圈速度是1000us，此時FPGA Sine Generator的Frequency設定為10Hz，那輸出的sine wave會是10Hz嗎? 謝謝。

Hi, wwc
在LabVIEW視窗內按Ctrl+H可以開啟說明視窗，而由說明視窗可以知道Table size的意思，請見下圖
以上圖來說，這個Sin generator產生1024點的10KHz的sin波的DATA
所以如果要正確輸出10KHz的sin波，您的輸出頻率要注意是否會影響輸出波形的頻率
希望以上訊息能夠解答您的問題, 若還是有疑問, 再請您回文,
若是覺得問題有解決而且答案還滿意, 也請您勾選已解決的選項以及惠賜一個獎勵 ( Kudos )囉!
謝謝!NI應用工程部
AAron

Creating random timeseries in Labview to Arbitrary wave generator

I do not know anything about Labview but somehow i need to get this task done.
How do i make a random data time series using the data arrays in a text file to be generated into the arbitrary wave generator? Can somebody please provide an example file for this?
Thank you in advance.

Hello Nazerrul,
There are several ways to do something like this.
First, many Arbs also have function generating capabilities, including random noise generation. What exact arb are you using?
If your arb doesn't have this capability you could use the Gaussian White Noise Waveform VI to create a noise waveform that you could then load into your arbitrary waveform generator. How to do this part depends on your arb. What exact arb are you using?
In short, more information is needed, including the arb you are using and what you have done so far in getting this to work.
Regards,
Dan King

Question about the customized FPGA signal generator.

I connected the AO0 and AO1 ports to the oscilloscope. But I got nothing. What should I do?
Attachments:
Customized FPGA Signal Generator.lvproj ‏2159 KB

Hi CZ_Kevin,
When attaching a project, it might be best to zip the project folder, or attach your VIs, so that we can look at your code. As for the screenshot, it looks like you might be using too many resources on the FPGA but again it is hard to determine without looking at your code.
Since you are using a myRIO, you might get better responses by posting to the Academic Hardware Products forum as this handles many myRIO questions.
Also, there are many pre-built project templates and examples within LabVIEW that might be worth exploring as well as a project guide that includes many tuturials. You can find the latter here.
David C

I need help adding two signal waveforms from a square wave generator using an or gate

Hey Im working on a square wave pulse signal that can be displayed using an FPGA board. I have two different pulses (signal 1 and 2) generated from square wave generators on LabVIEW each with equal duty ratios but different phase offsets. I need to add the two pulse signals together to get another signal (signal 3) showing two pulses (from signal 1 and 2). I have tried using an Or gate but that wouldnt work as expected. Please I need some guidance on how to implement this boolean logic, P.S. Im open to any other solutions. Thanks.
For clarity: Imagine signal 1 = 00001000
signal 2 = 00100000
I need signal 3 to be = 00101000, I hope this emphasizes my point.

The problem is with the third function from the left. Oops, I forgot, I'm not clairvoyant. Maybe if you posted your code, we could really tell you if the problem is the third function from the left ...
Bob Schor

Discrete sine wave generator

im lookin for a way to build a simple discrete sinewave gen that can generate up to 100MHz or more. Does a pll helps, can i use a crystal oscillator to generate the sinewave or even clock generator? pls reply mi asap. Thanks!

Hello,
This forum is for questions pertaining to the National Instruments product "Measure for Windows". I think you would reach a better audience for your question if you posted in one of the "Measurement Hardware" forums.
Good luck, and have a nice day.
Darren
Darren Nattinger, CLA
LabVIEW Artisan and Nugget Penman

TWO independent square wave generators on sbrio9632 fpga

I am using sbrio9632, I need to generate 2 different PWM signals for driving 2 different motors in the same time. I`ve put 2 square wave generators but when I change the parameters (frequency, duty cycle) of the first generator, the parameters of the second generator are automatically changed. So i supose that there is only one square wave generator that can be used. Any solution ? Is it possible to use 2 different square generators on the same board ?
Thank you !

The Square Wave Generator is a little quirky when operating outside of a Single-Cycle Timed Loop, because it needs to ensure that it is called at a rate that will produce the edges of the square wave with precise timing. So it operates similar to a loop timer, in that it blocks execution until it is ready to output a high-low or low-high transition. See the example at examples\R Series\FPGA Fundamentals\Analysis and Control\Square Wave Generator\Square Wave Generator (FPGA).vi for more information.

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

Generating Triangular and sawtooth waveforms in FPGA

I need to generate triangular and saw tooth wave form in FPGA and give it to my testing system, But I cannot generate it, there are options for generating sine wave and square wave only.
I am currently using Compact RIO 9025 with NI9215,9263,9403 modules.
Pls tell me is that possible to generate those waveforms and if it is possible describe me how to do that.

Hello,
There are 2 good documents that will help you get started with this task. There are, of course, many ways you can implement this and the right way will very much depend on your application.
Periodic Waveform Generation with RIO Enabled Hardware and LabVIEW FPGA
Triangle Wave Generated PWM
If you need more to get started, I'd be happy to assist further, but I think these are enough to get you down the right path.
Cheers!
TJ G

Fpga HDL code generator

    Hello,
It seems that FPGA module cannot interface custom FPGA board.
I wonder if FPGA can be used as a HDL code generator.
Here is what I'd like to do :
- code an algorithm in a LabVIEW block diagram
- make a HDL from the BG with FPGA module
- build the HDL code in my FPGA IDE (Quartus II, in this case)
- download it in my FPGA target with the JTAG probe
- use RS232 (or any VISA interface) to communicate the results to another LabVIEW vi
The main question is : can LabVIEW FPGA module generate HDL code ?
Thanks,

Hello,
The LabVIEW FPGA module generates *.vhd files, located in the directory C:\NIFPGA80\clntTmp\[projectDir]\ (if you use LabVIEW 8.0); those files are then sent to Xilinx tools to generate the FPGA bitfile. LabVIEW FPGA module is not designed for non-NI products, this is why those intermediate files are encrypted.
Cordially,
.mrLeft{float:left} .mrInfo{border-left:solid 1px #989898;font-size:x-small;color:#989898}
Mathieu R.
  CTD - Certified TestStand Developer / Développeur TestStand Certifié
  CLAD - Certified LabVIEW Associate Developer

How to generate 3 phase sine wave to output on ELVIS

Hi .I need to make a star or delta connected circuit on ELVIS board.2 make this circuit I need 3 wave generator( with 120 phase shift) and one common ground
and because the ELVIS function generator can only generate one wave I decided to generate countionuos sine wave in Labview.
Now I can generate 2 continuis sine wave in labview and output them on the analog outputs of ELVIS.Ao-0 and A0-1
but I dont know what to do for the third signal.the elvis board just has 2 analouge output and when I use Ao-0 and A0-1 I cant use ELVIS function generator after that.so would u please help me on this problem.how can I output 3 contious sine wave in Elvis.I have attached my VI to this post
Attachments:
new.vi ‏38 KB

Hi, I am also having some problem in generating two signals from two AO. Could you please tell me how to generate two different signals from two AO. I have attached vi which generate square wave from one AO 0. I need the inverted signal in AO 1.
Attachments:
Pulse Width Modulation.vi ‏48 KB

FFT of Sine Wave-FPGA

Also tried generating a sine wave of 50 Hz and an amplitude of 100 and then do an FFT. But the FFT does not give magnitude at 50 Hz..
Attachments:
FFT-2_Sine Wave Generator.PNG ‏52 KB

Your problem is that the output of the FFT is an array of complex numbers. Take the magnitude and you will be able to plot it.

FPGA wave generator precision

Similar Messages

Maybe you are looking for