FFT of digital data

Similar Questions

• DAQ USB 6363 - generate digital data series through the single DIO line

  Hello

  I'm new with Labview, currently, I bought NI DAQ USB 6363 for generating control signals and signals analog accquire. I would like to send digital data series through one of the digital IOs with throughput of 30 kbps. Please see the attachment for the data frame. Could someone comment the feasibility of this? Y at - it codes for the example that I can refer to? Most of the examples I've looked at so far deals to generate several line instead of 1 single line. How can I achieve this?

  Thank you

  Diem

  Hey diem.

  After looking on your code, I understand what you were trying to do. Here's how I'd do. Usually we do not write code to clients, but you peaked my curiosity of! I hope this helps. Good luck!

  ~ kgarrett

• Maximize the continuous digital data recording rate

  I'm trying to record digital data clocked outside large amounts quickly.  The data is only for post-processing.  What is the best way to get data from the port on the hard drive at the fastest possible pace?

  I connect using a PCIe 6537 B.  I log on 4, ports of 8 bits to 40,92 Mhz, so a rate of ~ 160MBytes per second.  I have two designs I've tried so far (a producer-consumer architecture and a DAQ.mx configure logging design).  Both models work if I connect only on two ports (effectively halfing the necessary flow) but fail to the width of 32 bits.

  My producer consumer architecture fails after about 30 seconds of recording successful message

  Error - 200613: Acquisition was stopped to avoid a crushing of the input buffer.

  My other DAQ.mx configures logging design fails quickly (~ 1 sec) with

  200361 error: Overflow memory on-board

  .

  I could be set it up incorrectly.  As I said, it works with 16-bit data width.  I don't know if the increase in the width of the data directly is the problem or if the increased flow to fail.

  I use this on a 3 GB ram windows xp using labview in 2012.  I have attached the vi of my two attempts and a picture of the DAQ.mx set the logging design.

  Well, I'd suggest the integrated PDM recording method would probably be you give best results, assuming that it works at all.  This record type opens a DMA channel of the material on the hard drive so it should not produce copies of useless data, which would probably be a producer consumer loop.

  I never tried logging TDMS without reading the data, a Read DAQmx should be used in the loop?  Your file contains TDMS data?

  The challenge of your hard drive?  It is a flat disk of laptop?  I recommend you test on a SSD, if possible, just to see.

  There are also properties to open up to a size of memory buffer.

  Start with one of the logging TDMS basic examples delivered with LabVIEW and work your way up from there.

• How can I use internal clock case OR USB - 6259 BNC for the acquisition of digital data in my own big software?

  I want to integrate the ANSI C sample program ReadDigPort - ExtClk.c in my own big package.

  I want to use the internal clock of the BNC NI USB-6259 (.. 80 kHz 120 kHz).

  In the document:
  High speed M: Series Multifunction DAQ for USB - 16-bit, up to 1.25 MECH built-in BNC connectivity. / s,.
  is written:
  Or sample DI source clock: Any PFI, RTSI, HAVE sample or convert clock, AO, Ctr n out internal and many other signals sample clock
  The digital subsystem doesn't have its own dedicated internal synchronization engine. Therefore, a sample clock must be provided another subsystem on the device or from an external source.

  How can I use internal clock case OR USB - 6259 BNC for the acquisition of digital data in my own big software?
  With what other subsystem on the device can generate a source of the clock? How?

  It is possible to set a clock on an internal counter (for example ' Dev1/ctr0"):
  Creates channels to generate digital impulses that define the freq and dutyCycle and adds the channel of the task that you specify with taskHandle.
  DAQmxCreateCOPulseChanFreq (taskHandle, "Dev1/ctr0" units, clockName, idleState,
  initialDelay, freq, the duty cycle); works

  But it is not possible to drive this internal clock to a terminal (for example "/ PFI0/Dev1"):
  DAQmxErrChk (DAQmxCreateCOPulseChanFreq (taskHandle, "/ PFI0/Dev1", clockName, units, idleState, '))
  initialDelay, freq, the duty cycle); does not work: error DAQmx: measurements: type I/O of the physical channel does not match the type of I/O required for the virtual channel you create. Name of the physical channel: PFI0. Name of the virtual channel: clock

  The sample clock source can be derived from an external terminal (for example "/ PFI0/Dev1"):
  Sets the source of the sample clock, the sample clock rate and the number of samples to acquire or generate.
  DAQmxCfgSampClkTiming (taskHandle, "/ PFI0/Dev1", maximumExpectedSamplingRate, DAQmx_Val_Rising, ")
  DAQmx_Val_ContSamps, bufferSize); works. Acquire or generate samples until you stop the task

  But it is not possible to derive the internal counter of the clock (for example ' Dev1/ctr0"):
  DAQmxCfgSampClkTiming (taskHandle, "Dev1/ctr0", maximumExpectedSamplingRate, DAQmx_Val_Rising,
  DAQmx_Val_ContSamps, bufferSize); does not work. Error: Acquire or generate samples until you stop the task: make sure that the name of the terminal is valid for the specified device. See Measurement & Automation explore valid names of terminals. Property: Property of DAQmx_SampClk_Src: DAQmx_SampClk_ActiveEdgeSource device: Terminal Source Dev1: Dev1/ctr0

  Hi datafriend,

  using what it says is correct:

  Or sample DI source clock: Any PFI, RTSI, HAVE sample or convert clock, AO, Ctr n out internal and many other signals sample clock
  The digital subsystem doesn't have its own dedicated internal synchronization engine. Therefore, a sample clock must be provided another subsystem on the device or from an external source.

  This means that if you do not use an external signal as clock you can use the sample clock to HAVE it on board or at the output of the internal counter.

  There are also 2 ANSI C examples in this regard:

  http://zone.NI.com/DevZone/CDA/EPD/p/ID/4485

  http://zone.NI.com/DevZone/CDA/EPD/p/ID/4488

  So in both cases you have to use a fictitious task you need only for the generation of the internal clock (HAVE or CTR)

• accuracy of digital data from LabVIEW

  Hello!

  I have a question about the accuracy of data, Labview, is perhaps a silly question, but it drives me crazy.

  If I use a digital constant and I put for example 1 (I mean 1E-6), it looks like 1E-6 but I found that it is not really 1E-6, actually if I raise the precision and I use 17 digits, 1E-6-9, 9999999999999996E-7.

  Could someone explain to me what is happening for digital data?

  Thank you

  It is one of the most frequently asked questions ever.

  The trick is in how computers represent floating point value. I remember a lot of right answers already given in the forum, but I am not able to find the most comprehensive and clearest.

  For example, one of the answers is here.

• How can I determine what digital data was issued last with the regeneration?

  Is there a way to determine the last digital data output if you are running a quick revival and regeneration?  Right now I use a digital channel not used by the channel with the same clock that I use for other data capture. It works very well and I know that the data I receive are correct, but there is something wrong with burning a channel for that. The data I am regenerating changes several times during the trial for counting samples to determine where I was in the buffer would make my code more complex and the chances of a mistake to increase.

  I have a mixture of material that I use for a cDAQ-9172, a box of series M and a PXI-1033 USB.

  Hello Tom,

  There is absolutely something wrong with having to use one of your channels to monitor what you're out, however, it's the best we can right now.  The problem is, when you set a buffer until the release, the access card to this memory stream location it will regulate.  It's speed leaving and overall card design.  There is no way back on the material for do what you are looking for and no software to interact directly with the location of the buffer.

• Application of logic gates on digital data... How does it work?

  Hello

  While working with labview, I tried to apply or digital data, he agreed the entry and responded to the output form digital too.

  I did not understand how is - this work on a digital data when entering are supposed to be Boolean for the logical entry doors.

  The outputs are also out of the assumption to 5 | 4 gives results 5.

  Also, I am attaching my VI.

  Please inform what is the logic behind this calculation.

  Concerning

  Hello

  logical operations operate with integers (any will do) too. The integer is used at the level of the ILO...

  The outputs are also out of the assumption to 5 | 4 gives results 5.

  5 is "0101" in binary representation, 4 is "0100":

  0101 OR
  0100
  ____
  0101 result
  

• What is Western Digital Data LifeGuard Diagnostics?

  Friends-

  I noted in my start/programs, a new piece of software has been added to the list, and I needed to install it. It is called Western Digital Data LifeGuard Diagnostics. I don't know where it comes from, so I guess it's an auto-update from Ms. The problem is that when I Googled it and it raised online on Microsoft.com, all references were too opaque for me to grasp what, exactly, does it.

  Its own pages of support, he said that "it is a version of Windows Data LifeGuard Diagnostics. It will test the internal and external WD drives. In additional, it can provide you with the model and series of WD drives attached to the system. "Huh? Why would I want or need this information?

  I am wary of what he is and does (quite thin on explanation there), but there seems to be so many things about it that I am comfortable, considering that it is not a scam/spam. The problem is, where he comes and what benefit can it give me? Sorry if I am too a novice on this, but I have never heard of him.

  Any information would be welcome. Thank you.

  Hello MDBoy,

  From an internet search, Western Digital Data LifeGuard Diagnostics is a program that performs hard drive diagnostics.

  The utility can make identification of the drive, diagnostics and repairs on a Western Digital FireWire, USB or EIDE drive. In addition, it can provide you the series and model of the player numbers.

  In addition, there is a feature called write zeros: this option can be used to clear the operating systems and file systems.

  So if you do not install this software, I would say you uninstall and remove this diagnostic software. You can go into Control Panel, click programs and features. Western Digital Data LifeGuard Diagnostics must be there. There is a column it installed on. This will give you the date, that the software has been installed, then it can give you a clue.

  Thank you

  Marilyn

• How can I search for files in a range of digital data

  Is there a way to specify a range of digital data in Windows 7 search for example File1 through deposer10 included

  Thank you

  So you're saying that file names could be, for example, hotdog4.txt for hotdog15.txt?  Well, you can look for in an orderly series, numerically and alphabetically, with two periods between the first and the last item, as in name:hotdog4.txt... hotdog15.txt

  Interestingly, Windows by default notice when the names correspond to a digital frame and so will sort hotdog4 to hotdog10 and so on, despite 4 being a number greater than 1 Prime figure 10.  I found a reference to this topic (but do not disable anything probably, just for the pleasure of reading):

  http://www.askvg.com/how-to-disable-numerical-file-name-sorting-and-enable-classic-literal-sorting-in-Windows-XP-Vista-and-7-Explorer/

• Using CC of Muse, I want to generate a survey in order to process digital data.

  Hi all

  Very new to web design and Muse.  I'm currently looking through tutorials for basic usage.

  My question is, can I generate a survey that will collect digital data based on questions such as:

  "How many times a week do you...." »

  I so want the data to be processed based on the parameters and weightings etc. which I stated, and gives the user a rating based on their responses.

  This kind of thing is possible in the Muse? Or do I need a design software web based code?

  See you soon

  James.

  Hi James

  Yes it is possible if you host your site with Business Catalyst.

  Web Forms can be used to collect data with custom fields, and then you can filter using the generation of reports.

  Data collection and rating submitted data are 2 separate process, for example, I have a field in my booking form "how many seats" and boxes option to select numbers. This process will allow to save user data submitted. On another page, I have a blog/forum where user submits its history and then people can comment on, and note the element, which is a separate process.

  Both can be carried out on the end of BC.

  and in case you want to all the functions to be put on the same form, you must use Web applications, with which it is possible.

  For example, I create a web application and an application form for comments and same time I configure to display presentations on my web page where viewers can rate/comment on submissions.

  Please go through these documents for more details:

  http://helpx.Adobe.com/business-catalyst/using/create-insert-form.html

  http://helpx.Adobe.com/business-catalyst/partner/add-Forum.html

  http://helpx.Adobe.com/business-catalyst/using/add-blog.html

  http://helpx.Adobe.com/business-catalyst/partner/Web-apps-module-create-custom.html

  Thank you

  Sanjit

• Reports on the string data when it crashes more than digital data

  It is an interesting situation for me. My apologies to simplify the introduction to the problem.
  
  It's easy when I met data from the table, a table, you have your descriptive data (Look up table)... Name of the product, the Transaction name,..., etc and you have a related table with the digital data in it (Table of facts),..., sales, cost, margin,... etc.
  
  Of course when the table with digital data in it breaks down further than the table with descriptive data. The solution is simple. Simply summarize you the data grouping in the descriptive table of digital data.
  
  ... Ok. Sorry about all this. Now, here's my problem...
  
  I have a situation where my table (get) descriptive data breaks down further than digital data in my table of facts. I know there is no way to summarize the data of type string, but I need a way to report the values in my eyes to the top of the table on the same line as the digital data cell associated with TWO or MORE look for rows in the table.
  
  I bet that this is not the first time that it has produced in the history of the RDBMS, so I think there must be a methodology out there somewhere to handle this situation.
  
  I think the final result will be something like; concatenate the descriptive data in the description cell that will be reported next to the digital data on the same line. I just need to know what the official solution, when it exists. There must be. Or at least a clever work around...
  
  Does anyone know what it is or how to handle this? Even more, is there a formal name for this kind of situation?
  
  Thanks in advance!
  

• FFT of the data in a table

  I would like to perform an FFT on a digital signal periodic sampling.  For the moment, my signal is stored as an array of 16-bit integers (0-65534) item 8192.

  I tried to connect this table directly at the entrance of the fft.vi X, but the data that comes out of the FFT {X} seem little logic (table length 8192 with spikes, the beginning and the end of it).

  Any advice would be much appreciated.

  Okay, that's better

  The reason why you don't see the desired result of FFT is easy:

  (a) you have a shift of 8000 to your signal. He is peaking at 0.

  (b) your signal includes approximately 2.6 times. Given that the FFT concatenates virtually your signal from - inf to + inf in the time domain, your signal a 'jump' inside that create spikes in your field of frequency 'somewhere '. To prevent this, you can either use windowing or cut the signal of your time domain to contain a whole number of periods (which would then along 6400 samples).

  hope this helps,

  Norbert

• Problem with the digital data to write VISA function

  I have a GE's PowerPC that is running on the VxWorks operating system. I have a tornado application where I run my C code to generate a file .o & .out, then I empty image .o files & .out for PowerPC via FTP, now I need to communicate with PowerPC of LabVIEW (via serial communication using VISA vi) using the VxWorks controls. When I enter orders VxWorks in LabVIEW

  That is to say for Eg: 1 > ls --> the contents of a directory list IE .o & .out files. The problem I'm facing here is, when I run the vi, I am able to read the file in the box to read the string but keep files on speeding up juice,

  2 > ld <> --> load a module object in memory. I face the same problem here.

  3 > then I need to type the name of funtion main c program, after which I can give input to the program.

  4 > I need to enter numeric data as inputs to my program. but the write VISA function accepts the only input string and read VISA function gives only out of string... I want to give digital entries and read the digital output.  Any help would be appreciated.

  Hi Luke,.

  You can try with this reliable hyperterminal VI.

  http://lavag.org/files/file/172-hyper-Terminal/

• analog and digital data synchronization

  Hi all

  I would like to help with what I seek to accomplish, if you don't mind much.

  I'm trying to synchronize the acquisition of analog and digital modes using a common trigger that launches both types of data collection at the same time. What I've done so far, is wasting his time trying different combinations to gather examples of LabVIEW 2011 on the synchronization of data - namely the 'Multi-multifunction-Synch AI lu Dig Chan.vi' and 'Multi-Device Synch-Analog Input-Finite Acq-Analog Start.vi.

  I tried to combine the two, because one contains digital and analog, the other contains the trigger for multiple tasks.

  I guess I should place the trigger (either digital or analog-eventually I will want to choose) then call the "Get Terminal name with device Prefix.vi. But from there I'm not sure wheter to connect the name of the terminal of the sample clock digital channel or a digital leading edge of the digital chain trigger.

  Also, the way it is wired now I get errors at the local terminal name, so I don't know exactly where this terminal must come from.

  I try my best, I could use a little help, I have attached my attempt with the examples that I speak to you.

  Thank you.

  Hi beefcake.

  The CtrInternalOutput internal output line is used as sample for your digital output sample clock source clock. If you change the settings for your CO Pulse Time is Dev1 and your digital output is Dev2, you will notice that the name of the product terminal would give Dev2/CtrInternalOutput. So what you get here, it's as well as the digital output device sees his sample clock, instead of the clock itself.

  If you just want to use a digital/analog input as your trigger, you should do something more as in the example above. Do you use multiple devices, or are all your lines on the same device? This example is more complicated because it is synchronization of signals on several devices.

  Looking at how this VI is wired, you can see that the digital signal triggers the analog signal. You want the analogue signal must be started first, so that when the digital signal triggers the analog task is already running and can trigger immediately. If the digital task started first, it can trigger until the similar task had started, and they do not exactly trigger at the same time.

  I hope that clarifies things. Kind regards

• Parcel FFT of sampled data

  I have already tasted the data of an input in the time domain signal. the signals are sampled by ADC and stored in excel file (about 16 K samples). I need to feed to the FFT VI for the plot of the FFT. I tried several bolts of FFT, but nobody does not accept data samples directly which is stored in the table 1 d. Any ideas? Thank you.

  Hi ABM26,

  Your input signal looks like a pure sine wave.  You perform the FFT and get the amplitude.  So you get two peaks in the result.  I think it is the correct result.   Why do you think the result of the FFT is false?

  And I realize that you want to calculate what the power spectrum.  You can use the Signal Processing > spectrum analysis > Power Spectrum.vi directly.