Digital waveform frequency measurment

Hi,
i have Motor driver can give me the speed as feedback "digital waveform"
the frequency is proporational with the speed
i have Cdaq 9188
also i have ni9401
1. at which slot i have to connect the cmodule 9401 to be able to reach the counters ?
2. how i have to connect the speed feedback to module ?
3. can i have guide about this issue ?
thanks alot

Try posting in english here
Translation 
Digital waveform editor to create waveforms PXIe-6536 I want to output, what do I like?
I do not know the correct response is, at present we take the following approach.
① Digital waveform editor creates a waveform
   1.. Hws as the output file format
   2. "NI-HWS Express (load)" read
   3. VI confirmed the digital waveform graph output.
② PXIe-6536 for creating DAQ Assistant
   1. PXIe-6536 digital output in
   2. DAQ output waveform creation screen test assistant
   3. NI CB-2162 has been confirmed that the output waveform on
   4. DAQ Assistant SUCCESS
Is conducted to the point where there are some drawbacks, however.
    * DAQ Assistant, you run alone, I get an error
"-200,077 Error code is DAQmx Write (Digital 1D Wfm NChan NSamp). Vi: 3 occurred in
 Measurements: Requested value is a value that is not supported at this property.
Property: Output.BufSize
Requested value: 0
Minimum: 2
Maximum: 4294967295 "
    HWS * DAQ Assistant VI to read the attached file for the connection can not connect For the loop to be taken into
    * Thereafter, the sample rate settings do and what do I like?
Such situation.
Us, Labview for complete beginners because it is, I do not know how you like the above is correct.
And I think there are many points, but fall short, you can ask that solved until you have any opinion you have any

Similar Messages

  • Waveform Frequency Measurement

    Hi,
      are there any VI witch perform waveform frequency measurement? I tried the express vi "Analyze  >> Waveform Measurements >> Timing and Transition Measurements", but when the waveform sampled is 16.65MHz and it shows about 16.49...MHz. How can I take a better precision in this measurement?

    Hi,
    What is the maximum sampling rate for the data acquisition card you are using for this application. If you don't know can you just send me its number. because if you are reading a signal with frequency higher than twice sampling rate you will have wrong reading "Aliasing". if you checked the previous requirments for correct acquisition you can try using "extract single tone information.vi" located in the Functions>>all Functions>>Analyze>>Waveform measurements.
    good luck
    Tareq

  • Is the digital waveform graph supported in Measurement Studio?

    I have an application that could really use the LV-style digital waveform graph in Visual C++. Are there any plans to support the digital graph in Measurement Studio?
    Thanks, Bob

    Unfortunately, there is currently not an equivalent of LabVIEW's digital waveform graph in Measuremeht Studio for Visual C++. You can fake some of the features with CNiGraph. If you have Measurement Studio for Visual Basic 6.0 installed, you can see some examples of this in the VB DAQ\Digital\Digital Waveform and Digital Waveform Continuous examples. Also, attached is a sample Visual C++ 6.0 project that demonstrates how you can simulate some digital graph features with CNiGraph. There's also a screenshot attached that shows what this looks like. Hope this helps.
    - Elton
    Attachments:
    DigitalGraphExample.png ‏16 KB
    GraphDemo.zip ‏19 KB

  • Digital frequency measurement speed in labview

    I am using a USB 6210 device to measure low frequencies of 50 to 1000 Hz. I need to log the frequency every 50ms. I do this in a while loop in labview using a 1 counter low frequency measurement in labview and saving the data using express VI.Each iteration of the loop takes atleast 60 to 100 ms just to read the frequency inside the loop. How do i increase the speed of measurement in Labview ?
    Solved!
    Go to Solution.

    PraveenB,
    Here is a table of the Counter terminals and related PFI lines.  This can be found in the NI DAQmx Help. (http://digital.ni.com/public.nsf/allkb/CCDFC93878BD8781862570FC00559980?OpenDocument)
    Default NI-DAQmx Counter Terminals
    Counter/Timer Signal
    Default Pin Number
    Signal Name
    CTR 0 SRC
    1
    PFI 0
    CTR 0 GATE
    2
    PFI 1
    CTR 0 AUX
    1
    PFI 0
    CTR 0 OUT
    6
    PFI 4
    CTR 0 A
    1
    PFI 0
    CTR 0 Z
    3
    PFI 2
    CTR 0 B
    2
    PFI 1
    CTR 1 SRC
    4
    PFI 3
    CTR 1 GATE
    3
    PFI 2
    CTR 1 AUX
    4
    PFI 3
    CTR 1 OUT
    7
    PFI 5
    CTR 1 A
    4
    PFI 3
    CTR 1 Z
    2
    PFI 1
    CTR 1 B
    3
    PFI 2
    FREQ OUT
    8
    PFI 6
    When you choose counter 1 in the Create channel VI it automatically reserves the gate which is PFI2.  If you use Counter 0 then PFI 2 will work fine.  Likewise if you use Counter 1 you can use anything but PFI 2.
    Message Edited by Jason_D on 10-24-2008 11:43 AM
    Sincerely,
    Jason Daming
    Applications Engineer
    National Instruments
    http://www.ni.com/support

  • Digital waveform output

    hello everybody
    first of all: i'm working with m-series card pci 6259 and measurement studio c++.
    i want to output digital waveforms to sixteen digital outputs.
    the waveform buffer should contain at least 720 points.
    the frequency at which the output should be changed is varying between 24kHz and 120kHz.
    when one waveform buffer is done, it must be recalculated, frequency adjusted and output again, and so on...
    in the data sheet of my card i read about waveform characteristics of port 0. but i can't find any
    documentation about this anywhere.
    so can anyone help me with this problem?
    regards
    markus

    The standard installation of NI-DAQmx puts an item into the Start menu: Start->National Instruments->NI-DAQ->NI-DAQmx C Reference Help.
    Look under C Functions->Channel Configuration/Creation->Create Digital Output Channels, and Write Functions, various DAQmxWriteDigital... functions.
    Look in the NI-DAQmx Concepts section for various kinds of information about digital output.
    Look for the C-language examples under Program Files\National Instruments\NI-DAQ\Examples\DAQmx ANSI C\.
    John Weeks
    WaveMetrics, Inc.
    Phone (503) 620-3001
    Fax (503) 620-6754
    www.wavemetrics.com

  • Unstable Frequency Measurement USB6210

    Hi All, 
    I'm struggling to get a stable frequency measurement, to measure the RPM of a motor, using a single counter on a USB6210 board. 
    I'm using the +5V TTL signal to power an opto-transistor, and reading that signal back through Ctr0 (PFI1). See attached wiring schematic.
    I've put a scope in line (between PFI1 and DGND), and at the PFI1 terminal get a square wave, about 50Hz, peaks at about 2.5V. Do I need to be linking this signal to DGND, and how?
    I've set up a task in MAX, and readings fluctuate from 45Hz to 900Hz.
    I've also tried to read this in LabVIEW using the example VI - Meas Dig Frequency-Low Freq 1 Ctr.vi. I then get even more random results of +100,000 (full scale).
    Many Thanks,
    Martin 
    Attachments:
    Counter Wiring.jpg ‏63 KB
    24022010044.jpg ‏397 KB

    thanks a lot John P, i'll try it this vi config.
    well, my flow transmiter should give an 0-5 volts signal with frequency between 0 and 100 hz (datasheet here), and the data i need is codified in pulse frequency, the measured voltaje is wrong but frequency on oscilloscope is ok. i attached pics of my signal on oscilloscope measured on transmitter output, measures at daq card input are the same, i connected my transmitter ground to digital ground (im working on ni pci 6221).
    i tried the  Minimum Pulse Width option with 2.56 ms but now i realized why did'nt worked (voltaje level issues ), but now my typical noise is 3% of my signal, i think noise won't be a big deal.
    and i was surprised too about this system could get data acquisition insteand of data timeout error (because of voltaje level's issues), at first test i performed the system made the measures already mentioned, but i realized the ones who made this system attached the signal acquisition line to waterpump's power source (in fact, they attatched all data signal's lines to waterpump's power source ¬¬) and they hid noise effects with waveform's settings, now i fixed this and the system only shows me data timeout error.
    initially i got confused because if im getting frequency acquisition of milivolts signal i thought daq card's counter input could deal with it, but now i realized it was just noise peak effects.
    best regards
    .:. Pedro Rivera .:.
    i love to work and develop on labview, this is real fun!!!
    Attachments:
    signal acquisition.zip ‏355 KB

  • Simultaneous analog and digital waveform read with PXIe-6361 and BNC2120 ?

    Hi there,
    I am trying to collect both analog and digital signals from a PXIe-6361 linked to a BNC2120, using the attached VI. I am running Labview 2011 64bit. This is the first time I am working with digital input. On the 2120 board, I have the digital input BNC cable connected to User Input 1 and wire between the screw terminal of UserInput 1 and the P0.1 (Digtial I/O) screw terminal.
    I have two questions related to this:
    1) When I try to run the VI in its current state, I get the following error:
    Error -89137 occurred at DAQmx Start Task.vi:3
    Possible reason(s): Specified route cannot be satisfied, because it requires resources that are currently in use by another route.
    Property: RefClk.Src
    Source Device: PXI1Slot2
    Source Terminal: PXIe_Clk100
    Required Resources in Use by
    Task Name: _unnamedTask<6>
    Source Device: PXI1Slot2
    Source Terminal: None
    Destination Device: PXI1Slot2
    Destination Terminal: RefClockInternal
    Can anyone point me in the right direction for troubleshooting this?
    2) I would like to combine my regular waveforms and the digital waveform into one array which would then be written to file. I can't figure out how to combine the two different waveform types...can anyone give me a hint on this?
    Thanks for your help,
    Claire.
    Attachments:
    Export Waveforms To Spreadsheet File (1D)_wo extra line.vi ‏33 KB
    Multi-Device Synch-Analog Input-Finite Acq-Analog Start_Claire_wDigitalin.vi ‏105 KB

    Hi ClaireJ,
    Sounds like a reference clock conflict. This KnowledgeBase (KB) talks about this error when using simultaneous sampling. Also, might want to check the device routes in Measurement and Automation Explorer (MAX) as discussed here. Finally, if you are routing your PFI line over a RTSI connection, this error can occur. This KB discusses it.
    As to your second question, this post should help.
    Bill E. | Applications Engineer | National Instruments

  • How do I output three digital waveforms at once?

    I posted this in Digital I/O, but now I think it's actually more appropriate here because it's not a hardware question. I need to output three digital waveforms at a relatively low frequency, 71.9 Hz. I have a PCI DAQ card, the 6024E and am using the NI-DAQmx functions to try to do this. My program basically generates the square wave that I want, and converts it into a digital wave. I do this 3 times for the three separate waves, and then I combine them into an array and send them to my DAQ functions, which are in a while loop so I can get continuous output. My problem is that the waveform that the DAQ is actually outputting is not what I want. It's outputting a wave that has the same duty cycle (approximately) but the frequency is over 2 kilohertz. It's not like this all the time; after it outputs about 7 cycles of this wave, it goes to logic low for a long time, and then repeats itself. When I probe the digital waveform right before it goes into the DAQ functions, it's running correctly at 71.9 Hertz. Am I doing anything wrong with the DAQ functions or the sampling information? Thanks in advance.
    -- Josh Matloff

    Hello Josh,
    I'm pretty sure that the reason that your digital waveforms are not being produced at the correct frequency is because your digital output is not associated with any sort of timing. Unfortunately, with an E series board you can only do software timed digital operations. This means that the frequency at which the values on your digital lines will be updated depends on how fast/often your computer executes the DAQmx Write that is inside of your while loop. If you have an M series board, you can actually correlate the DIO operations with another subsytems clock (AI/AO sample clock, etc.) which means that you can acheive hardware-timed DIO. In the event that you do not have access to an M series board, I think that AnalogKid2DigitalMan was spot on that you would want to use counters to generate pulse trains (that is if your digital waveforms have a constant duty cycle and period). Depending on what the DAQ board is outputting to, you might also want to consider using the Analog Output channels to generate your digital waveform. As long as you continue to use the digital lines on the 6024E, there is not really a way to guarantee the timing of when the digital lines will be updated. You might be able to get close, but you will probably see some "hiccups", especially if your computer needs to service interrupts or give processing time to another application. And lastly, heed geckoee's advice and don't forget to properly close out your tasks! Putting in some error handling may also help in the debugging process.
    Take care,
    E.Lee
    Eric
    DE For Life!

  • How can we substitute the invalid option "reset after read" in FP-CTR-500 + FP-1600 frequency measurement application?

    We nned to incorpore the values of 2 frequency signals (0-10 Khz)into a process controlled by a VisualBasic application running on 1 PC with W'95. Because the FP-CTR-500 working with FP-1600 hasn't the option "reset after read", the process of reading is a bit complicate, and sometimes, we receive wrong values of frequency from those devices. Could you help me? Is there any extremely reliable method of reading? Best regards,
    Puho

    For frequency measurement information on the FP-CTR-500/502 modules. Please see KnowledgeBase Article #1TB63SUS
    http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/d8db42f9fdc3607e862568640047f144?OpenDocument
    Ultimately, the FP-CTR-500/502 modules are not designed for frequency measurement, although it is possible to use them to measure frequency. The one thing is that it works best to do the measurements over relatively long integration periods (1/4 second or more).
    Regards,
    Aaron

  • Digital Waveform graph with a lot of samples

    Hi,
    I have to display in a Digital Waveform Graph a lot of data read from a file(2.000.000 of samples for 36 signals). If I read the file and I try to display all the data, the Vi became unusable. For example, to zoom a graph region, it may take 30-40 seconds, scroll is impossible ecc, ecc..
    Apparently LV doesn't perform a decimation of points. In measurements studio 8, this problem doesn't exist...but I have to use LV 7.1..
    any suggestion ?
    At the moment I have developed a DLL in VC++ that perform a decimation of samples, but performance are not very good !
    Thank you for any idea.
    Regards.

    Hi Garraty,
    Excuse me but I have several questions for you.
    1)     Have you tried some kind of incremental approach, starting from 1 waveform and increasing towards 36? Do you experience some kind of on/off degeneration between, les’s say, 34 and 35 waveforms?
    2)     How can you decimate a digital pseudorandom sequence of 2M samples without loosing information?
    3)     Is this 2M samples an unavoidable constraint for your application?. Actually, it seems very difficult to extract some kind of visual information from a pseudorandom pattern of this length?
    Thank you very much.
    Kind Regards
    FiloP
    FiloP
    It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong.
    Richard P. Feynman

  • How to use a photogate for frequency measurement using a NI USB-6211

    Hello, I am extremely new to LabView and am having trouble using the counter feature (or if this is even what I should be doing). I am trying to use a photogate as a frequency counter when a voltage spike is created by blocking the sensor. This will then be put into RPM and used to evaluate a small motor dyno I am creating. If anyone has any help or previous vi's they dont mind sharing it would be greatly appreciated. The photogate specifications are for an optek opb930l55. Thanks 

    Configuring a counter input task will be a little different depending on the type of DAQ card that you are using to read the digital pulses.  You just need to wire the voltage from the photogate to one of the counter pins on the card.  Then follow one of the many examples for measuring the frequency of pulses.  If your card allows it, I would suggest choosing the Counter Input >> Frequency measurement from the DAQmx Create Channel VI.  If you have questions about how to do this with your specific DAQ device, please provide more information
    Zach C.
    Field Engineer
    Greater Los Angeles

  • New M Series DDK Example: High Frequency Measurement with 2 Counters

    This example demonstrates how to configure two counters on an M Series device to measure a high digital frequency. One counter generates a continuous pulse train of a set frequency while the other counts the external signal using the pulse train to latch values. Data is transferred via DMA.
    Use this example to add high digital frequency measurements or DMA data transfer for counter input to your driver.
    Please let me know if you have questions or problems. Thanks :-)
    Joe Friedchicken
    NI VirtualBench Application Software
    Get with your fellow hardware users :: [ NI's VirtualBench User Group ]
    Get with your fellow OS users :: [ NI's Linux User Group ] [ NI's OS X User Group ]
    Get with your fellow developers :: [ NI's DAQmx Base User Group ] [ NI's DDK User Group ]
    Senior Software Engineer :: Multifunction Instruments Applications Group
    Software Engineer :: Measurements RLP Group (until Mar 2014)
    Applications Engineer :: High Speed Product Group (until Sep 2008)
    Attachments:
    gpctex5.cpp.gz ‏4 KB

    You should connect the signal (whose frequency needs to be measured) to Ctr-1, and there gonna be an internal connection between the output of the first counter and the gate of the second counter (as described here).
    You may want to check this link as well.
    I am not allergic to Kudos, in fact I love Kudos.
     Make your LabVIEW experience more CONVENIENT.

  • DAQ frequency measurement using anolog input channel

    Hello,
    I try to develop a DAQ application which run on a real time target.
    I want to measure frequency using anolo inpur channel of my DAQ card. I have a problem.
    Let me first try to explain what i trying to do. In the first loop i do sampling and show the result as double array.
    I need to show samples as double array so i can not read sample as waveform. With a shared variable i sent these samples to second loop.
    First loop reriod is msec and second loops period is 20 msec.So when the second loop run, 20 samples were alraady ready, frequency measurement is done.
    The problem is that i need to show frequency measurement as far as possible. Say frequency of my signal is about 100 hz, then this
    configuration gives correct frequency measurement. But if frequency of the signal is about 10 hz, this configuration fails since period of second loop is 10 msec and it is not enough time to measure a 10 hz signal. But if i adjust period of the second loop as 100msec,
    then i can measure 10 hz signal but then i can give measurement of a 100 hz signal  +90msec late. What can i do so i can measure frequency af signals ranges 0-100hz and give measurement result as far as possible?
    Attachments:
    measure_amp_freq.GIF ‏35 KB

    eesen,
    What you are doing doesn't make any sense to me. First of all, you should take multiple samples with the DAQmx Read and not one sample at time with the timed loop. Your frequency measurement will then actually be more accurate. You also should return a waveform. That includes timing information that the Freq & Amp function needs to determine the frequency. It cannot do it with a dbl array. If you have to display a dbl, then just use the Get Waveform Components to extract the y array. You can get rid of the second timed loop and use a regular loop for the DAQmx Read. If you just set the rate to be twice the highest input frequency and acquire enough samples for a couple of cycles, you should have a pretty accurate reading.

  • Real-time - how to control speed of digital waveform

    Deploying the VI attached to my RT desktop target I generate digital waveform on 8 channels on port0 and acquire data on AI [PXIe-6358].
    The digital output frequency and analog input sample frequency are 10000 Hz therefore I expect that while one 8-bit digital code is active [valid] for 100us, one single analog sample is acquired. That means that I would expect one cycle of the while loop to finish in 100us x 2^8 = 100us x 256 = 25600us = 25.6ms.
    However what happens is that the while loop finishes in 6ms regardless the set frequency. The loop finishes in 6ms even if I set 5/10/15kHz or if I put a 100us delay into the while loop. I also tried to set the source of the analog input sample clock to 'Dev/do/SampleClock' but nothing seemed to work so far.
    How can I force the digital generation to be in correlation with the analog acquisition? I need to acquire 1 data point per channel while the respective digital code is active.
    Thanks,
    Krivan
    Attachments:
    RT_ai_dig_wave_gen.vi ‏56 KB

    Hello krivan,
    Thank you for your post on the forum.
    Do you want the digital generation to start at the same time as the analog acquisition?
    Shalini B
    Applications Engineer
    National Instruments UK & Ireland

  • Why does my AI acquisition slow down to my frequency measurement rate?

    I'm using Labview/Daqmx to program my SCXI 1520 and TC modules while at the same time using the multifunction capabilities of the E-card controlling the SCXI.  This has been fairly easy until I wanted to use the frequency and counter measurements (outputs/DIO works great).  I'm using a waveform with buffered acquisition for the read on the AI channels and obviously there is no waveform for the frequency measurement so I'm just combining the signals using the dynamic data.  This works great when my input frequency is higher than my acquisition frequency.  When my input frequency is lower than my acquisition frequency the acquisition slows down to that frequency and the AI read falls behind (buffer fills while waiting for another frequency measurement).  I'm assuming the frequency read is not keeping up with AI read.  I understand that as the frequency is reduced it takes more time to calculate the frequency.  So how do I "read" the frequency measurement at the same rate as the AI data?  I'm fine with using the last frequency measurement until a new frequency measurement is available but I can't even seem to be able to do that.
    An example of the problem is measurement of vehicle pedal force (AI channel) with pulse input for vehicle speed.  Assuming 100 Hz acquisition and the vehicle stopped or going slow (very slow pulse train) I should be able to acquire data at 100 Hz even if I just use the last data point for the frequency channel until another point is available.
    Please help, thanks.

    Basically, the very fact that you're *doing* a frequency read suggests that you don't know the expected freq ahead of time, and probably suggests that it can vary.  The waveform datatype assumes a constant interval between samples which wouldn't generally be true for frequency measurement, and that's why you can't use it.  Since the actual timestamps of the frequency measurements are NOT the same as those in the analog waveform, it's likely a mistake to pretend they are.
    My method is to create my own array of "timestamps" for the frequency data.  Create a For loop with a shift register initialized to 0 from outside the loop.  Let your freq array auto-index the loop.  On each element, perform (1/x).  Add result to the left-hand shift register value and write it to both the right-hand shift register and to an auto-indexing output.  When the loop completes, the output array will hold timestamps that correlate to your freq measurements.  From there you can choose whether to display on an X-Y Graph, or whether to perform some interpolations to calculate freqs at the analog sample times or vice versa.
    -Kevin P.

Maybe you are looking for