• RELEVANCY SCORE 3.77

    DB:3.77:Analogue Signal Pulse Count 19





    I am using CDAQ with a NI9229 4 Channel analgoue input card.

    I have a sensor that outputs an analogue 5v square wave signal. The pulses are triggered from eithe a north or south pole of a magnet. I have an aluminium wheel with 30 magnets, all magnets are in opposition to each other. when the wheel is rotated the output is a square wave.

    My magnet wheel is rotating at 182° per second. Over 360 degrees there is 30 magnets. Thus making the sensor switch 30 times.

    The time to revolve the wheel one revolution is 1.978 seconds.

    I have set up the NI9229 to the following

    - sampling rate is set to 25kS/s So to record the data for one revolution it works out as 49450 bits.

    - Have set the trigger levels for recording a hi or lo pulse to 2.7 and 0.7 volts.

    50000 samples would be two seconds worth of data which would be more than 360° of rotation of the magnet wheel.

    The problem I am having is that my pulse count changes between 30 and 31. But as I am only recording 1 revolution of data there is physically only 30 switches. Do you know why I am getting a change of 30 and 31.










    Attachments:







    pulse count 2.PNG ‏20 KB

    DB:3.77:Analogue Signal Pulse Count 19


    Ok thanks

    Thats ok as the CDAQ i am using uses a 9205, 9411 9474, 9229

    I will see what i can figure out today and get back to you.

  • RELEVANCY SCORE 3.61

    DB:3.61:Dc Motor Position Control 8z





    Hello,

    I am novice in Labview. I am hoping that this is the right section to post this question. I am using a cRio 9076 Module with NI-9264 and NI-9205 analogue output and input cards. I am trying to control (PID) a motor with encoder on its back(http://www.pololu.com/catalog/product/1447). I have attached a the VI which counts the high pulses of both channels. I want to uses the pulse count to control the motor, i.e i want to set the motor to certain position by sending analogue signal by setting the desired pulse.

    I have made a VI for control. Idont know whether i am going the right way to control.I can only increase the analogue voltage. But cannot decrease it in the controller

    Any help would be graetly appreciated.










    Attachments:







    encoderTest.vi ‏33 KB

    DB:3.61:Dc Motor Position Control 8z


    Hi

    To start with, how fast do you need to sample the encoder? I'm trying to figure out the specs, it looks like a slow speed motor, so sampling at 1kHz (which is the scan mode you are using) may be fast enough to detect all the encoder pulses. If you need to sample faster than 1kHz you'll have to use FPGA mode.

    It looks like your edge detection fo the encoder is set up correctly. Is the motor position or speed controlled by the analogue voltage? As far as I can see from the specs, the motor ranges between 40-80 rpm depending on the input voltage.

    If you want to do PID control, there is functionality available in the "PID Fuzzy logic" toolkit, if you have access to that.

    You'll need to put in some code to translate the encoder pulses into a current speed so that you can perform the control.




    Ian SApplications Engineer CLDNational Instruments UKIreland

  • RELEVANCY SCORE 3.37

    DB:3.37:Pulse Counter Using Daq pa



    I have USB-6008 Daq hardware and labview.

    I am trying to build a photodiode sensor, so basically my circuit will give out pulses signal (think of it as square wave or sine wave signals). It gives a signal whenever it is triggered. I am trying to count each pulse that occured during the testing.

    Now, how can I build a pulse counter. I am just starting to learn to use labview, so I am trying to find the easiest way to accomplish this.

    Currently, I am using signal generator to test it (with repeating square wave). Can anyone please help? Most of the VI is too hard for me to grasp

    Basically, it just needs to count every pulse in real time (and show the count result in numeric indicator).

    A sample vi would be really helpful? thank you in advance

    DB:3.37:Pulse Counter Using Daq pa


    The 6008 does have an event counter and an example for it - Count Digital Events.VI.

  • RELEVANCY SCORE 3.30

    DB:3.30:Using A Counter On Pci-6023e Daq Card fd


    Hi there,I'm about to use a 6023 card to measure a periodic pulse signal. I need to count the number of the pulses. But...I've heard that the counters on my card are unusable in that case. Is that correct? Do I have to chage my card? Or can I do it with 6023E?Thanks in advance;Radek

    DB:3.30:Using A Counter On Pci-6023e Daq Card fd

    Hi DAC,The counter on your 6023E board is the DAQ-STC counter/timer. This counter fully supports counting the number of pulses. Depending on your application development environment, if you search the shipping examples you will find examples that perform this function.This is so long as your digital pulses are 0-5 V or TTL compatible. Other applications supported by your counter are:Simple event countingGated-event countingSingle-period measurementSingle pulse-width measurementSingle pulse generationSingle triggered pulse generationRetriggerable single pulse generationContinuous pulse-train generationBuffered event counting Buffered period measurement Buffered semi-period measurement Buffered pulse-width measurement Frequency measurementBuffered frequency measurement Finite pulse-train generationQuadrature encodersHope that helps. Have a good day.RonApplication EngineeringNational Instruments

  • RELEVANCY SCORE 3.19

    DB:3.19:Pulse Count Using Ni 9403 Dio Module 9f



    I am trying to count pulses from a quadrature encoder using cDAQ system with DIO module NI 9403and AI module 9205. I dont have h/w with inbuilt counters, so have to do away with whatever i have. I programmed to compare the incoming signal with a reference voltage level (3Volt) and count the number of times it exceed that level. This way I should know the number of times pulses are generated.But the program is not working.

    The encoder is of **bleep**or automation make (Model: S 3000) which generates 3000 pulses per revolution.

    Please help.

    DB:3.19:Pulse Count Using Ni 9403 Dio Module 9f


    The better way to do this (if you want to trigger off of a configurable voltage level) would be to configure an analog trigger and count the "analog comparison event" using an on-board counter (there are 4 on the 9178 which I think you are using based on your other thread).

    I don't have a cDAQ chassis handy but I think something like this should work (if you don't want to read back analog data you can replace the read with an "Is Task Done?" call and add a wait to the loop, you may need to configure the task to overwrite unread samples if you do this):

    If your input is a TTL signal and you don't actually need to configure the trigger threshhold, you may instead route the PFI line on the 9205 directly to the backplane counter without using an analog input task (EDIT: You'll want a wait call inside this loop since the task is no longer blocking the loop execution, ~100 ms should be sufficient to throttle your loop rate to avoid unnecessarily spinning the CPU):

    Best Regards,




    John Passiak

  • RELEVANCY SCORE 3.14

    DB:3.14:Usb6008 Hardware Timed Period Pulse Counting fd



    Hi,

    I have a USB6008multifunction DAQ and am trying to use it for pulse counting in Matlab through calls to the dll. What I would like to know is if there isany way to use a built in clock of the DAQ to count the pulses in a period of, say, 10 ms instead of using the timing function is Matlab on my old and overworked pc that is unlikely to be particularly accurate. Failing this, what would be thebest counter tobuy? My signal comes from a photon counter which has amaximumpule rate of 20e6 / s (the 5Mhz on the usb6008 is a comprimise). The frquency is certainly not fixed and so pulse counting rather than frequency calculation is what is needed.

    Thanks, any help would be appreciated (even in coding)

    Ali

    DB:3.14:Usb6008 Hardware Timed Period Pulse Counting fd


    Hi Ali,

    The USB-6008 doesn't support hardware timing. Refer to this KB.

    Regards,




    Rico P

  • RELEVANCY SCORE 3.13

    DB:3.13:Pulse Count ax


    Hi,

    I have a pulse and I would like to know how much pulse have been obtained since the start of the program.

    All I can obtain is the time delay between two pulses.

    May I know where the block to count pulse is?

    Thank you very much,

    Alexander

    DB:3.13:Pulse Count ax

    Hi Alexander, Please keep your posts on the same topic (counting digital events) to a single post. This is very similar to the first answer which I posted here. To count a total number of pulses (up to terminal count), you would want to use a counter in Simple Event Counting mode. There is a example that does exactly this, please take a look at: Count Digital Events.VI Please reply to the linked forum location above, this helps keep our community clean of parallel threads on the same topice. Best regards, MatthewWApplications Engineer National Instruments

  • RELEVANCY SCORE 3.13

    DB:3.13:Want To Count Number Of Times "1" Comes In Digital Signal. 7x



    I am using USB 6210 I/O and want to count the pulses in my digital signal generated by gear tooth sensor. I have integrated the whie loop within the case structure. Firstly case structure identifies the "1" value in digital signal and starts incrementing the local variable. The While loop I used is to increment once only when single pulse comes. if i remove the while loop then it increments the local variable continously till next zero comes(in a single pulse).

    But even after having while loop within the case structure and changing the while loop stop condition to "stop if true", the program stuck in the while loop.

    Can anybody tell me how to do this ?

    DB:3.13:Want To Count Number Of Times "1" Comes In Digital Signal. 7x

    Indiano wrote:

    You are right, but fortunetly i have applied some digital logic with shift registers.

    Anyway, Thanks.

    Fair enough, but doing it this way will ultimately limit how fastof a signal you can measure (might not be an issue for you).

    Best Regards,




    John Passiak

  • RELEVANCY SCORE 3.07

    DB:3.07:Looking At Output Counter Signal fd



    Hello,

    I am using the NI 6132 multifunction daq card and am outputting a continous pulse out of my counter0 out pin. I would like to somehow monitor what Im actually outputting..Ive tried sending the output of the counter back into an analogue input of the card and ive also tried a PFI input but have had no success...any help would be appreciated.

    Thanks

    agi

    DB:3.07:Looking At Output Counter Signal fd


    Hi Agi,

    Your application sounds very interesting, you wont be able to read in a counter from an analogue input so to start with wire the Ctr0 Ouput (Pin2) to PFI3 (Pin42). This will allow you to read in a pulse train generated on Ctr0 from Ctr1.

    Please let me know how you get on with this.




    Ben LField EngineerNational Instruments

  • RELEVANCY SCORE 3.06

    DB:3.06:Pulse Oximeter 3x


    As a project. I am developing my own pulse oximeter and i am going to be using a DAQ 6211. There are four things i need to do with lab view which i have no idea how to do. I am very new to Lab view.

    Ok the circuit i am building has a receiver and a transmitter. The transmitter has two LEDs that need to take control signals to turn on one at a time. Therefore, the control signals into the light diodes need to be time multiplexed.
    There needs to be a carrier of certain frequencies outputed from my other analogue output. This way both of my analogue outputs are used.

    Furthermore, i am using a AD630 to demodulate the am modulated signal. The synchronisation signal for this needs to come out of an digital output.

    Furthermore, on the receiver end i need to collect data. This needs to create a pulse signal by recognising the peaks, where the peaks are not spike like.

    I am just wondering if there isa program already on labview that someout could send me? or help me with?

    DB:3.06:Pulse Oximeter 3x

    I had read the mentioned threads. However, my problem is i need to get two analogue signals out of the DAQ, one going to each of my LEDS.

    So that one needs to be off while the other one is transmitting carrier signal

    red led:^^^^^_____^^^^^...

    ir led:_____^^^^^_____..

    Something like the above. So i am wondering how i can get a signal out of each of the analogue outputs of the DAQ USB 6211 to implement this. Hence, one needs to be off while the other one is transmitting (probably i was thinking a multiplexer somewhere would do) but not so sure. I am completely new to Labview. Anyone can give me a hint? or is there a program like this that anyone has already.

    Furthermore, i need one more output for my sychronization signal at the receiver. However, since i am out of analogue output this needs to be implemented with a digital output (but needs to be the same frequency as the above carriers). Any thoughts? Or any programs for Labview?

    Your help is appreciated in advance .

  • RELEVANCY SCORE 3.05

    DB:3.05:Analogue Output Sync Digital Pulse kj


    Hello Attached is a VI that has one analogue out in a form of a user inputed equation, which is made up of two frequencies.A second waveform if generated but not outputed (WV2). It is used asreference signal to generate TTL pulses at every zero crossing on a digital line. With Help of an ni engineer I manged to get a pulse at every zero crossing for a one Hertz wave, but do not get any pulses at higher frequencies to show on the scope even though the boolean indicated a digital output. I am sure that to find the zero crossing I need to use a shift register, but I am not sure how to incorporate it in the VI as apposed to using array max and min. I need the timing to be accurate so that the delay between the zero crossing and the TTL output is the minimum possilbe. Also I would like for the digital line to go to zero after my application is done as it stays at five. Furthermore is ther anyway I can change the pulse width or duration.

    Thank you
    Ala

    DB:3.05:Analogue Output Sync Digital Pulse kj

    HI Tom,

    I have labview 8.0, would you mind saving it in that format and posting it again.

    Cheers

    Ala

  • RELEVANCY SCORE 3.03

    DB:3.03:How Can I Measure A Fraction Of A Pulse dp


    I have a pulse signal that is somewhat steady and I need to be able to count the pulsesvery accurately. The pulses are streaming in(from 10 Hz to 100,000Hz)and then an external trigger marks the beginning of the count and then sometime later(maybe 6 secondsto 20 minutes) the same external trigger marks the end of the count. The beginning of the count will have a fraction of a pulsebefore the whole pulses are counted. Also the end of the pulse will have a fraction after the last whole pulse was counted. We do this now with an "in house" made ckt bd that uses 555 timers and J-K flip flops etc, to achieve pulse interpolation out to 4 decimal places.This gating board was made in the late 80's has served us well, but we are upgrading our system and we would like to replace it with something that is supported, without losing accuracy. The type of pulse interpolation we currently use is a Duel Chronometry, but the new one can be Quadruple Timing or Phase-Locked-Loop, etc. types of pulse interpolation. This pulse count is then sent so we can use in calculations.

    If you have hardware that can do this, I will need 2 (possibly 3) of them.

    Thanks, Charley

    DB:3.03:How Can I Measure A Fraction Of A Pulse dp

    Hi Charley,I understand your problem now. Thanks for the details. If your width is constant then yes, you will be able to measure the width of a fraction of a pulse using multiple counters and some programming. You would count the pulses coming in, the internal 80MHz timebase, and use the trigger on a PFI line to start and stop all your tasks. You could use the incoming pulses as the read clock for the counter that is counting the timebase and, assuming constant width of the incoming pulses, you can calculate the difference between how many timebase ticks were counted in a full cycle (two ticks of the pulses) and how many were counted from the first trigger to the first rising edge of the pulse. The pulse fraction will be measured in multiples of 12.5ns which (assuming 50% duty cycle of the incoming pulses) will be 0.025% of the width of the pulse at 100kHz. You can use this concept at the end of the pulse train as well. The duty cycle requirement is not required, just used as an example to give an accuracy percentage.When counting for a long period of time, you may exeed the 32bit register of the counter. This is not a problem because you can monitor the CtrnTerminalOutput pin which will indicate when this happens and you can account for this. I hope this information is useful and you feel that an NI counter/timer board such as the 6602 or the 6608 can perform the desired application.



    PBearNI RF

  • RELEVANCY SCORE 3.02

    DB:3.02:Card With Trigger Event And Hardware Counter? cj


    want to have a card with fuctions:

    1) trigger an event by an external elec-photo sensor.( need 2 on the card)

    2) hardware counter (count optic encoder signal pulse, 0-200hz) .

    is there a card like this ?

    or even 2 seperate cards?

    thanks

    DB:3.02:Card With Trigger Event And Hardware Counter? cj


    Hi zy9,

    Thank you for posting to the NI forums. For a specific device recommendation, please post back with the following information.

    1. Type of event being triggered

    2. Output range of the photo-sensor

    3. Output range of the optic encoder

    Our Multifunction DAQ Devices (M Series) will probably be your best option. These include analog and digital triggering as well as two 32-bit counters for your encoder signal.

    In addition to the M Series devices’ product pages, you can also use our DAQ product selector to find a good match for your application. It will allow you to narrow down your search results by selecting specific functions that the device must have.

    I hope this helps! Please post back if you have more information or any further questions.

    Regards,

    Ed WaxlerApplications Engineer

    National Instruments

  • RELEVANCY SCORE 3.02

    DB:3.02:Can I Count The Number Of Pulse At 20mhz From A Gpio Port With Frdm-K64f? ak



    Good morning!

    For the project of an acquisitor with k64 MCU, can be useful to count the number of adc conversion that I store in a FIFO memory.

    The problem is if I can mesure the number of pulse of a 20MHz signal that I have in GPIO input with the port interrupt.

    The k64 is setted for 120MHz of core clock and 60MHz of bus clock.

    Do you think I can count pulses at this frequency with this micro?

    Alessio Paolucci

    DB:3.02:Can I Count The Number Of Pulse At 20mhz From A Gpio Port With Frdm-K64f? ak


    Thanks Earl, even I thought of feed the timer with the external clock , but unfortunately in the FRDM - K64F this input is not available , then I can do this test only once I have the MCU. If I try this, I will say you if all works.

    Best Regards

    Alessio

  • RELEVANCY SCORE 3.01

    DB:3.01:Can Pci-6601 Pulse Signal Over Rtsi Every Nth Encoder Count? ca



    Hi All,

    I have a PCI-6601 counter/timer connected to a quadrature angular encoder. The 6601 is also connected to a PCI-1422 frame grabber with a RTSI cable.

    I want to be able to trigger the frame grabber by sending a pulse over the RTSI cable every N encoder counts (or X degrees).

    How would I go about do this using C++?

    Thanks in advance,

    Brad

    DB:3.01:Can Pci-6601 Pulse Signal Over Rtsi Every Nth Encoder Count? ca


    Hi Brad,

    There are a few resources I think you may find helpful. First, there's this DevZone article, " Generate and output pulse every no count an encoder traverses". Generally, the way this would work is:

    If you want to output a pulse every 4 counts, you will need to take the
    total count size of the counter (2^32 bits) and subtract 4 from this.
    This will be the initial count to set, so that after 4 counts, the
    counter will reach Terminal Count and the Counter Output Event pulse
    will be fired. You can then export the Counter Output Event to a PFI
    line, and use this line as the Z index terminal. If you set the Z index
    value to be equal to the initial count, the counter will always reset
    to 4 ticks below the Terminal Count, and will output a pulse on every
    4th tick. The only drawback to this method is that it will require that
    only X1 decoding be used, and that the counter would have to be
    dedicated to sending out the Counter Output Event (if you want to
    actually count the encoder and keep track of position, another counter
    will have to be used).

    As for specifically doing this in C++, I would recommend referencing the DAQmx C Reference Help (Start»All Programs»National Instruments»NI-DAQ»Text Based Code Support»DAQmx C Reference Help). Hope that helps, for more assistance on the frame grabber portion of your question, I would reference the post you put in the vision forum. Have a great day!




    aNItaBApplications EngineerNational InstrumentsDigital Multimeters

  • RELEVANCY SCORE 3.00

    DB:3.00:Analogue And Digital Noise xc


    Hello all,

    I am using a 6110 analogue board and a DIO32HS board which are linked together internally to do simultanious aquisition. The application is in-cylinderpressure measurement from a engine. The engine has a pressure transducer which is linked to a charge amplifier (class 2 device, not earthed) which is then fed into the 6110 board. In order to keep track of where the engine is in the cycle the drive shaft of the engine is connected to a shaft encoder which give out pulses every 0.2dec and a pulse for top dead centre and bottom dead centre.

    My problem is as follows... The environment is very noisy. There is an inverter nearby which drives the dynomometer which keeps the engine at a constant rpm. There is also noise from the spark coils and discharge. This gives a noisy analogue signal, something which I think I could probably deal with by adding a low-pass filter in the analogue signal path. The real problem is the digital signals. Every so oftern, seemingly at random there is a spike in one of the digital signals. (i.e. a high value when there should not be one). What is the best way of dealing with this. Is it possible to use alow-pass filter on the digital lines as well or will this mess things up by attempting to filter a signal composed of high and low values. How should digital signals be earthed. At the moment the earth from the shaft encoder is connected to the earth on the digital board. All cables are shielded with BNC connectors.

    Many thanks, Tim

    DB:3.00:Analogue And Digital Noise xc


    I don't think a pull up resistor will solve the problem with the rather high low state voltage, it will rather increase this level. Pull-up resistors may be a solution when you have outputs with rather high leakage currents or a too low high state level.

    As mentioned, 0.7v low state voltage gives a pretty bad safety margin. It is not too difficult to brew your own level shifter, however you might find an off-the-shelf solution as indicated by the previous poster. Don't know whether Phoenix or Weidmueller components are easily available outside Europe but there might be equivalents from domestic suppliers.

  • RELEVANCY SCORE 2.99

    DB:2.99:How To Sync Can (Traditional) And Daqmx Input On Pxi? d7



    At the moment I am reading analogue samples and counter values on my PXI system. The counter value is incremented by an external pulse (i. e. current time). Because the pulse is the actual time, the AI sampling has to start in sync with the first incoming flank. This sync'ing is done via the DAQmx trigger VI which is set to "start at flank" (see picture). Because I am recording the counter values, too, I can always determine the time for each AI sample.

    Is it possible to start AI and CAN signal sampling in sync with the first incoming pulse flank? As before, I want to store the counter values as well, so that I have time information for each sample. Is this sync'ing solvable with VIs or do I have to use a different CAN card with an external trigger input?

    The CAN card is of type 8464 XS.


    DB:2.99:How To Sync Can (Traditional) And Daqmx Input On Pxi? d7

    Hello,

    please see the links below.

    http://digital.ni.com/public.nsf/allkb/95EB3CB8E92D30FB86256F2C00672C44?OpenDocument

    http://zone.ni.com/devzone/cda/tut/p/id/4204

    Regards

    Rüdiger

  • RELEVANCY SCORE 2.98

    DB:2.98:Acquire Images At The Rising Edge Of A Continuous Pulse Signal as



    I want to acquire images at the rising edge of a continuous external pulse signal .The external pulse signal is generated by other equipments.How should I integrate this continuous pulse signal to the CCD or IMAQ board? Is it to connect this pulse signal toone of TTL -trigger directly?

    Look forward for any advisable reply.










    Attachments:







    未命名.JPG ‏32 KB

    DB:2.98:Acquire Images At The Rising Edge Of A Continuous Pulse Signal as


    Hi xiao,

    Clarify these doubts,

    Do you want to trigger the camera? If so which camera you are using?.




    Sasi. Certified LabVIEW Associate Developer If you can DREAM it, You can DO it - Walt Disney

  • RELEVANCY SCORE 2.98

    DB:2.98:Convert Tv Signal From Digital To Analogue. xs


    As our TV signal has now changed to digital how can I convert to an analogue signal? If I attach a free view box with an aerial output into my Touchsmart IQ722 will it work?

    DB:2.98:Convert Tv Signal From Digital To Analogue. xs


    Those are some good questions! And I don't know the answers, but maybe this will help:

    http://www.ramelectronics.net/audio-video/audio-converters-extenders/analog-to-digital-digital-to-an...

    You might find some information that will help you,

    Good luck,

    GeorgeFN

  • RELEVANCY SCORE 2.96

    DB:2.96:How To Generate A Pulse On X Number Of Events Pci-6602 cj



    I am running LabVIEW 5.1 full development with a PCI-6602 counter board.

    I would like to generate an output pulse after counting x number of input pulses. I would also like to reset the counter with an external signal.

    My application is I am trying to generate a second index pulse for an encoder.

    I would like to count the pulses from encoder phase A and generate an output pulse on x number of counts. Then I would like to reset the counter using the encoder’s index pulse. This way I can change the phase of the “generated” index pulse with respect to the “real” index pulse by x number of counts (degrees) and maintain that regardless of encoder rpm.

    Thanks

    Brian

    DB:2.96:How To Generate A Pulse On X Number Of Events Pci-6602 cj

    Hi Brian-

    That sounds like a really cool application for LabVIEW- thanks for letting us know more about what you're working on! Let me know if the pulse generation doesn't turn out well or if you have additional questions.

    Thanks again-



    Tom WNational Instruments

  • RELEVANCY SCORE 2.95

    DB:2.95:I.Mx35 Gptimer Ext_Clk Pad 3x



    Hi All.

    I am i.MX35 newbie user. I wanna use the general purpose timer for a counter, to count external pulse number.

    In iMX35 RM, the timer has external clock source named ipp_ind_clk that is from pad, but the document does not illustrate which iMX35 pad mapped to the ipp_ind_clk signal.

    Could someone tell me which pad is used as GPtimer external clk input please? Many thanks!

    DB:2.95:I.Mx35 Gptimer Ext_Clk Pad 3x


    Hi All.

    I am i.MX35 newbie user. I wanna use the general purpose timer for a counter, to count external pulse number.

    In iMX35 RM, the timer has external clock source named ipp_ind_clk that is from pad, but the document does not illustrate which iMX35 pad mapped to the ipp_ind_clk signal.

    Could someone tell me which pad is used as GPtimer external clk input please? Many thanks!

  • RELEVANCY SCORE 2.95

    DB:2.95:Creating Piece-Wise Curves For Analogue Signal Output mc


    Hi guys,

    Im a LabView newbie, only just started working with it last week, but have completed many online tutorials so far.
    I have a project that i am working on currently that requires the representation of a certain waveform, with many of the parameters able to be changed dynamically on the fly. What im having trouble with is creating a piece-wise linear representation of this waveform.

    I think that I need to have it piecewise as the following variablesare ones that i need to change:
    On the voltage axis:
    Peak voltage output (analogue)
    Trough voltage output (or offset, also analogue)

    On the time access:
    Voltage Rise Fall times
    Pulse width
    Pulse frequency

    If anyone has done something similar, or if someone can point me on the right track it would be much appreciated!
    Thanks in advance

    Adam

    DB:2.95:Creating Piece-Wise Curves For Analogue Signal Output mc

    Hello Adam

    Are you looking to do this on the fly or are you wanting to generate a finite signal in the software with changes in the voltage and time axis.

    I amsume you want to generate a signal from your Multifunction DAC board. So you would like to generate some finite waveform signal so that you can change the the configurations of the waveform before generating a new finite signal.

    You would have to take a look at the "Gen Mult Volt Updates-Int Clk.vi" example from the example finder in LabVIEW.

    There are some signal generation functions in the analyze palette in the all functions palette.

    Regards
    Mo

  • RELEVANCY SCORE 2.95

    DB:2.95:More In Depth Daqmx Analogue Output/Input At Same Time. xk



    To all,

    Using the small tutorial located here

    http://zone.ni.com/devzone/cda/tut/p/id/4322#toc1

    I have been able to get my USB-6251 to ouput an analogue signal and also record analogue input at the same time. However the length of the output is equal to the length of my record time andI am looking to start reading and pulse at the same time but to read for say 3 mS but only pulse for 1 mS. Any and all help will be appreciated.

    Thanks in advance,

    Dan

    DB:2.95:More In Depth Daqmx Analogue Output/Input At Same Time. xk


    Hi Dan,

    Glad to hear that you were able to do synchronized acquisition and generation. If I understand you correctly, you now want to start at the same time, run at the same rate, but acquire for 3ms and generate for only 1ms. If this is the case, then I would suggest to create a finite task for each instead of the continuous task. You will no longer use the while loop. I would suggest to take a look at the LabVIEW Example Finder (HelpFind ExamplesHardware Input and OutputDAQmxAnalog MeasurementsVoltage). Take a look at the AcqGraph Voltage - Int Clk.vi. You can then modify your code to now do finite acquisition (for 3ms) and finite generation (1ms).




    Best regards,Rohan B

  • RELEVANCY SCORE 2.94

    DB:2.94:Xadc Problem/Bug In Simultaneous Sampling Mode ms



    Hello all,

    My application is a classical motor control application. I have to convert 8 to 16 analogue channels. The AD conversion sequenceis triggered by a SOC (start of conversion pulse). This SOC is generated usually ontimer underflow or overflow. This means the wholemeasurement sequence is synchronized with the PWM timer. One SOC pulse = 16 channels measured in a round.

    I'm trying to reproduce this behaviour on the Zynq device using the simultaneous sampling mode of the XADC.

    The expected behavior is that after the SOC pulse is generated (on CONVST input) the XADC does the conversions for the whole sequence. For 16 analogue channels this means that after roughly 8us from the SOCrising edgean EOS pulse should be generated. Since the 2 XADCs are working in simultaneous sampling mode and 1 conversion/ADC takes 1us I would expect that the whole sequence conversion should take roughly 8us.

    What I see is totally different. An SOC pulse triggers the conversion of only one??!! ADC pair and then the sequencer STOPS! It takes 8 consecutiveSOCs to have allthe2x8 channelsconvertedand an EOS (end of sequence)activated.

    My question is: Am I missing something? Is there any work-around in order to trigger a whole sequence (i.e 8-16 channels)with only one SOC pulse in simultaneous sampling mode?

    Otherwise do I have to generate in the PL an SOC pulsefor each analogue signal pairin the sequenceand to manage all the timings related to the ACQ intervalsand so on :(( ?

    I'm surprised by the behaviour I seesince what Ineed is a standard feature in motor control and I would expect to find it in a high end product like Zynq. This feature exists at least from the year 2000 in microcontrollers doing motor control.

    Note (if it makes any difference):

    I'm using a Z7020 device on a ZedBoard

    I'm using Vivado 2013.4

    Regards,

    DB:2.94:Xadc Problem/Bug In Simultaneous Sampling Mode ms


    Hi nitron,

    You can use simutaneous sampling mode with either event or continuous - because in all modes both ADCs of the XADC are always in lock-step.

    However, unfortunately your suggestion of using continuous mode and waiting for an EOS will not work, because as soon as you enable continuous mode the ADC begins converting - it does not wait for the external convst to start.

    So given this, the only viable solution appears to be generating 7 additional convert starts as previously described.

    Regarding the amount of time to wait for acqusition after busy falls - the actual acquisition time is of course dependent on the impedance of your inputs - but the XADC does begin acquiting the inputs before busy goes low.It may be good to allow for a variable number of cycles after busy falls in your convst generation logic for flexibility - and setting the default at (say) 4.

    Cheers,

    John

  • RELEVANCY SCORE 2.94

    DB:2.94:Is There Any Way Of Dropping The Analogue Output Signal To 0volts As Soon As I Stop Running The Vi. 9a



    Hi,

    I am looking to drop my analogue output signal to 0 volts as soon as i stop running my vi which contains awhile loop. I have an analogue output to a Variable speed driven pump and each time i stop running the analogue output locks at the last value. Any way of automatiically dropping this value to o volts.

    Dave

    DB:2.94:Is There Any Way Of Dropping The Analogue Output Signal To 0volts As Soon As I Stop Running The Vi. 9a


    All you have to do is set the value on your analog out to 0 outside of the while loop. Make sure you do something to create the data dependancy to ensure that the analog output will not exicute until after the loop has stopped.




    TimJohnson ControlsHolland Michigan

  • RELEVANCY SCORE 2.94

    DB:2.94:How To Measure How Long A Boolean Is High With Thick Count? am



    I acquire the pulse response from a Parallax Distance Sensor, but I I don't know how to measure the number of thicks that this signal is high (the time the input signal is high is proportional to the distance). I'd like to reset the thick count when this signal is low. is this possible? Is there another option?

    Thanks...







    Solved!
    Go to Solution.

    DB:2.94:How To Measure How Long A Boolean Is High With Thick Count? am


    I'm so sorry, I think I forgot to say that some data type and functional blocks are not available for FPGA Module. I cannot use double, neither HIgh Resolution Relative Seconds. I can just use the Tick Count Wait and Loop Timer. Also, thank you for replying my message so fast and create the Vi for me.

  • RELEVANCY SCORE 2.93

    DB:2.93:How To Count The Analog Input Pulses,Measure The Pulse Width, Determine The Mean Value And The Rms Value Of The Pulses? 8p


    Hi, i'm new user of LabVIEW. My concern is about how to count the analog varying pulses which generated by our muscle contraction? Besides, i want to measure the pulse width and determine the mean value and rms value of the pulses. Here i attach with my signal example. Is the counter function can be use? Is the counter only receive digital pulse? Anybody can help me? Give me some direction? Is there any example for me to refer? Need help urgently









    Attachments:







    Mastication signal on masseter muscle.doc ‏206 KB

    DB:2.93:How To Count The Analog Input Pulses,Measure The Pulse Width, Determine The Mean Value And The Rms Value Of The Pulses? 8p

    Proper EMG analysis depends on what information you wish to extract. A simple surface EMG analysis would go something like this:1. Full wave rectification (Functions - Absolute Value)2. Create a linear envelope - for example by passing data through a low-pass filter with a low cuttoff (ie Butterworth 2-5 Hz) (Analyze - Signal Processing - Filters)3. Integrating or finding max of each contraction.Or perhaps you are actually looking to extract the frequency content from your EMG - in which case there areSpectrum VIs under Analyze - Waveform Measurements.John.

  • RELEVANCY SCORE 2.91

    DB:2.91:How To Count Pulse With 6601 dd


    Hi,
    I am new to Labview. I am using PCI-6601 to count the pulses generated by the
    camera. (very simple!) The camera output is 5v. But I tried to test it first. I
    generated 10 pulses thru the LPT port and fed it to the counter board (6601)
    thru SOURCE (0) - Pin 2 and 36 and I took theoutput (OUT (0) Pin 5 and 39)
    and connected it to an LED. Now when I generate the pulse, I get 5.1 V but when
    connect, the signal dissipates and gives
    almost 0v. What am I doing wrong? If I disconnect the LED, I get the same
    result. Am I using the wrong pins?
    Please
    help!

    DB:2.91:How To Count Pulse With 6601 dd

    Thank you very much - I got it! But I have a new question - http://forums.ni.com/ni/board/message?board.id=170​thread.id=297599Message Edited by sha33 on 01-25-2008 03:23 PM

  • RELEVANCY SCORE 2.91

    DB:2.91:Pulse Measurement For 500hhz Signal fd



    I am using USB 6251 daq card. I need to measure the number of pulses arrived with in some start time and end time. the saignal can vary upto 500k hz.Also i need the pulse arrival time for all pulses.

    if i configure task for pulse width mesaurement in daqmx can i be able to measure the pulse count and pulse arrival time (upto 500khz)







    Solved!
    Go to Solution.

    DB:2.91:Pulse Measurement For 500hhz Signal fd


    I suppose what you are reffering to is the timestamp. when you use the low level VI's of DAQmx you can obtain the signals as waveform data type, which has the initial sample time t0, the sampling intervals dt as well the sample values array Y. You can do the rest by obtaining each of the parameters in waveform pallette.

    Hope this helps!




    Shreyas HebbareShreyas TechnologiesIndia

  • RELEVANCY SCORE 2.90

    DB:2.90:Buffered, Triggered Analogue Capture dp



    Hello there,

    I am hoping someone might be able to help me with my problem please. I'll try and describe the situation.

    - I have a pulse train from a motor encoder attached to counter 0 of my 6211 USB-daq card. This is set up to calculate pulse-periods. In my read loop I am reading 10 samples at a time. This is working great.

    - I also want to read say 4 analog samples on each rising edge of this encoder pulse train. I have set up a finite-sample sample clock with a a fast sample time. I have set up the trigger to be off PFI0 and I have fed the pulse train into that pin as well.

    - In the loop I then read 4 samples per iteration.

    - When I turn the motor shaft slowly by hand I confirm that all is working as it should - I get 10 period calculations every 10 edges and I get 4 analog values every single edge.

    Now for the problem.

    Depending no motor speed in the time it takes for me to iterate around my loop 5 (for example) rising edges may have occured. This is no problem for the period count - they are being buffered anyway. But, I only receive the latest 4 analog readings - I will have missed 4 sets of data.

    What I need to be able to do is read a 2D array of (for example) 4 sets of 4 data points. I can't figure out how to do this though...

    Please can anyone help?

    Thanks very much for any assitance,

    Martin







    Solved!
    Go to Solution.

    DB:2.90:Buffered, Triggered Analogue Capture dp


    Huh, you shouldn't need to disable filtering to show that attribute for your device. It should recognize that your device supports the attribute and show it be default. What version of DAQmx do you have installed? I'll investigate why that attribute wasn't showing up, and hopefully we can fix it (if it hasn't already been fixed in a later release)

    I'm glad everything worked out!




    ------Zach HindesNI RD

  • RELEVANCY SCORE 2.88

    DB:2.88:Counting A Ttl-Pulse Signal With Ni Daqpad-6015 pz


    I want to count TTL-pulses with NI DAQPad-6015. To which inputs must I connect the TTL-signal? I cannot find a detailed data sheet for this DAQPad-6015 USB-device. Can you help me, please?

    DB:2.88:Counting A Ttl-Pulse Signal With Ni Daqpad-6015 pz

    Thank you, this is clear. I found the information in the help file which you mentioned not to be very clear for a beginner like me.

  • RELEVANCY SCORE 2.85

    DB:2.85:Nidaqmx And 6220 Board - Retriggering To Start Sampling Analogue Signals k1


    I have a M series 6220 board with labview 7.I want to measure analogue signals using a digital trigger - much like the examples given in the library shipped with ver.7. However I want to "retrigger" periodically so that I can sample the my analogue signal each time my external circuit sends a trigger pulse out. This retriggering facility continuing until I press a stop button.At the moment all I can do is get one triggered set of samples and then the VI stops.Any code advice or examples would be appreciated. rgdsCharles (labview beginner)

    DB:2.85:Nidaqmx And 6220 Board - Retriggering To Start Sampling Analogue Signals k1

    There is an example that ships with NI-DAQ that will do this for you. It is called "Multi-Function-Ctr Retrigg Pulse Train Generation for AI Sample Clock.vi".I hope this helps!gus....

  • RELEVANCY SCORE 2.84

    DB:2.84:Rf Pulse Detection 99



    Hi all,

    I have a continious signal of 1,5V with a repeat RF pulse . I need to start ramp voltage during the RF pulse. How can synchronise the ramp voltage on the RF pulse. Fréquency of signal is 500 HZ an the RF pulse has 0,8 ms duration. Frequency and duration would be change for other experiment.

    Have you got idea to help me

    Thanks

    DB:2.84:Rf Pulse Detection 99


    Hello,

    Can you give some more information about the ramp signal you have to generate?

    What is the voltage and duration of the ramp.

    With the information I have you can use a multifunction DAQ board to acquire signals. As the 500Hz signal is low frequency, this is not a problem for the multifunction DAQ boards.Now you could use the analog triggering feature of certain Data Acquisition boards to determine the start point for generating the ramp. These special inputs on certain DAQ boards.

    This could be done by start triggering. Once you have a signal which comes above the DC part of your measurement you start generating the ramp signal.

    The digital representation of the ramp you have to generate, can be preloaded (possibly only partially) into a buffer on the DAQ board. So once you get above a certain input voltage, you start generating without the need to ask processor time. Everything is done on the DAQ board.

    If you need advise on which hardware to use, please contact your local National Instruments branch (http://www.ni.com/contact).They have qualified engineers who are willing to assist you in making the appropriate choice for you application.




    Best regards,JoeriNational InstrumentsApplications Engineeringhttp://www.ni.com/askMake our forums great: If you like the answer, don't forget to "Kudos!"."Accept the Solution" if your question is answered!

  • RELEVANCY SCORE 2.84

    DB:2.84:Generate An Output Pulse After N Ticks At A Counter Source 97


    I have a counter configured to generate a pulse after a specified number of ticks at the source. I have the signal routed to the source, but there seem to be errors counting quite often. If I tell it to count 50 pulses (~10 Hz pulses, 10 ms wide), it generates the output after anywhere from 46 - 53 pulses. It usually undercounts.

    The source is clean, it is being generated by another counter on a mx device, and it looks clean on a scope.

    The other question I have is I want it to count the falling edge of my pulse, it is counting the rising edge by default.

    DB:2.84:Generate An Output Pulse After N Ticks At A Counter Source 97

    Hello mheien,

    The Counter Output (Ticks) will generate a pulse which is high/low for the specified number of timebase ticks. Using the example program, Gen Dig Pulse-Retriggerable.vi and modifying it to include a property node to specify a falling active edge should give you the results you are looking for. The property you need to set is a channel property under Counter OutputGeneral PropertiesCounter TimebaseActive Edge, shown below. I used the timebase for the trigger as well.

    Here is the result of a task I ran for an output high of 5 ticks and output low of 5 ticks. You can see the timebase in red and my output in white.

    Hopefully this helps,

    Jennifer O.Applications EngineerNational Instruments

    Message Edited by Jennifer O on 01-18-2007 09:33 AM










    Attachments:







    CounterOutputTicks_FallingEdge.JPG ‏6 KB

  • RELEVANCY SCORE 2.83

    DB:2.83:Pci6602 And Divisor 88


    Hello,Development tools:Microsoft Visual C++ 6.0Measurement Studio 6.0We use one PCI6602 to count a "pulse signal" (we receive 6000 pulses/s). Is the PCI6602 card can output a division of this pulse signal (ie having 1 generated pulse every 10 pulses receive (by setting a divisor from PCI6602)) and if yes, which NI-DAQ commands to employ?Thanks a lot,Alain

    DB:2.83:Pci6602 And Divisor 88

    AlainI've attached one of the example programs that are installed with NI-DAQ. It is for pulse train generation. What you will need to do is set ulLowCount and ulHighCount accordingly. For your case you would want ulHighCount to be 10 and ulLowCount equal to however many pulses you would want the signal to be low. You will also have to change a parameter in GPCTR_Change_Parameter so it will use your external signal as the timebase. Change this line: iStatus = GPCTR_Change_Parameter(iDevice, ulGpctrNum, ND_SOURCE, ND_INTERNAL_100_KHZ); to this:iStatus = GPCTR_Change_Parameter (iDevice, ulGpctrNum, ND_SOURCE, ND_PFI_x); where 'x' is the PFI line of the Source of the Counter you are using. Then connect your external signal to the Source of that counter. For example, if you use counter 0, it would be PFI _39 and you would connect the signal to pin #2.Let me know if you have any problems with this.BrianPS: The program is called STC..., though it will work with the 6602.









    Attachments:







    STCgenerateSquareWave.C ‏5 KB

  • RELEVANCY SCORE 2.83

    DB:2.83:Pulse Width Measurements kd


    Hello,

    I am trying to measure the pulse witdth of a signal that has a pulse width of 800 micro seconds. I am using the pulse width measurement VI with an indicator on the pulse duration output. The sample rate I am using to sample the signal is 10000 samples/sec. The pulse width measurement VI is returning a value of 8. I'm assuming that it is taking the pulse width of the signal and dividing it by (1/10000) which is the time between each sample. Is this correct?

    Thanks

    DB:2.83:Pulse Width Measurements kd

    Hi Jimmy,You said that you were using the Pulse Width Measurement VI. Are you using the Express VI (LabVIEW 7 or higher), the regular VI, or are you trying to use a counter to measure do your PWM?Perhaps you could post a snippet of your code. It sounds like you've got the right answer, but knowing which method you are using could definitely help.Regards,



    OtisTraining and CertificationProduct Support EngineerNational Instruments

  • RELEVANCY SCORE 2.83

    DB:2.83:Low-Frequency Measurements Using Counter/Timer p1


    I am trying to measure speed, and am using the FP-502 counter timer module to count the pulses from my sensor. The field point example that uses a fixed width gate pulse will not work for my appliation because I need a gate pulse so big that it updates way to slow. Does anybody have any sugestions on how to measure a low frequency signal using a counter/timer?Thanks Dan

    DB:2.83:Low-Frequency Measurements Using Counter/Timer p1

    Hello Marcio,

    I noticed another post by tcrower that was answered by another AE. They posted the code at the other posting and helped him through some other problems as well. I hope this helps you.

    Steven T.

    http://forums.ni.com/ni/board/message?board.id=110message.id=3619requireLogin=False

  • RELEVANCY SCORE 2.82

    DB:2.82:Low Frequency Pulse Duration Measurement ac


    We have low frequncy pulse duration measurement to be done . We have tried with pulse measurement but it shows error for the frequency bellow 1.5 Hz. We have input signal of frequency varie from 0.5hz to 3 hz .Please suggest us is there any other method that can be used for mesureing the pulse width with low frequency mentioned above .If this can be done using tick count , please send us the example .

    Regards,
    Sharanu

    DB:2.82:Low Frequency Pulse Duration Measurement ac

    Hello Sharanu,

    I'm not sure you will be able to measure a frequency below 1.5 Hz in
    the traditional way. However, I would like to ask you some more
    questions about your system.

    1) What hardware are you using?
    2) What is the error you are receiving (please include the exact error text)?




    EricDE For Life!

  • RELEVANCY SCORE 2.82

    DB:2.82:Pulse Counter Using Lm3s8962 19



    Hello,

    I need the display and control this following points on EKK-LM3S8962 ARM board

    Generate the pulse signal.(as shown in excel file)
    After generating the pulse, 2 pulse is missing after 34.Then again start from 0-34(2 missing) as it continues.(as shown in excel file).
    At every 34 pulse I need to synchronize the cam single (as shown in excel file).
    At very synchronize I need to count and display on front panel.

    Please help me out as I am new to LabVIEW.










    Attachments:







    CrankSignals_Ref.xls ‏183 KB

    DB:2.82:Pulse Counter Using Lm3s8962 19


    Hello,

    I need the display and control this following points on EKK-LM3S8962 ARM board

    Generate the pulse signal.(as shown in excel file)
    After generating the pulse, 2 pulse is missing after 34.Then again start from 0-34(2 missing) as it continues.(as shown in excel file).
    At every 34 pulse I need to synchronize the cam single (as shown in excel file).
    At very synchronize I need to count and display on front panel.

    Please help me out as I am new to LabVIEW.










    Attachments:







    CrankSignals_Ref.xls ‏183 KB

  • RELEVANCY SCORE 2.82

    DB:2.82:Pci-6220 Generate A Digital Output Pulse Signal While Monitoring Analog Input Signal aj


    What is the best way to set up the PCI-6220 for a digital output signal of 0.2 sec pulse width(single shot) , while simultaneously capturing a analog input pulse train of 2.5 seconds. I need to analysis the return analog pulse signal.

    DB:2.82:Pci-6220 Generate A Digital Output Pulse Signal While Monitoring Analog Input Signal aj


    Could you provide an example that uses an express VI? I don't fully understand how to use DAQmx items, and my current VIs use Express VIs and I'm not sure how to integrate them.

    I am using a rotary encoder on a motor shaft, and want to send out a pulse train to trigger a camera. The rotary encoder outputs a relatively clean digital signal, at 1000 pulses / rotation. However, I would only like to send the trigger to the camera 25 times per rotation (so a decimating factor of 40).

    I am using LabVIEW 8.5 with a PCI-6251 and BNC-2110. There are two BNC connections under "Trigger/Counter": PFI0/AI START and CTR 0 OUT, and I was wondering if/how I should be using these connections, instead of analog input or digital input for the encoder signal, or where to send the output.

    Also, if you can provide any insight to how much, if any, of a delay will result from decimating the signal, or a way that I could measure that.

    Thanks!

  • RELEVANCY SCORE 2.82

    DB:2.82:Count Edges With 6036e 1f



    Hello !

    I am currently trying to count photons with a PCMIA 6036e.

    I have to detect a TTL signal ; each photon correspond to a pulse. So I tried to count rising edges, since one rising edge = one photon. I want to use either digital line or counter. Moreover, I have to count the rising edges for a limited time (typically 1s).

    I have tried several VIs, but none of them work. I either don't have an error message, but only 0 as a result, or an error message saying data were overwritten before they could be read.

    The problem does not come from the card, since it can count the rising edges in MAX. I have also tried examples such as "count digital events", but they give me the same error.

    I would appreciate any help !

    thanks,

    Camille

    DB:2.82:Count Edges With 6036e 1f


    Hello,

    Check carefully the wiring of your signal to the DAQ board; there is to main input for counter application, the source and the gate. Depending on the measurement you do, you have to wire your signal to the gate or to the source. In your case, the acquisition type should be a simple event counting. Using CTR0, the input signal should be wired to PFI8 (PFI3 for CTR1).

    Thespecification of the PCMCIA-6036Emention that the minimal pulse duration you can handle is 10ns in edge detect mode. If the pulse you measure are shorter, you will not be able to see it.

    Regards,




    .mrLeft{float:left} .mrInfo{border-left:solid 1px #989898;font-size:x-small;color:#989898}Mathieu R.
    CTD - Certified TestStand Developer / Développeur TestStand CertifiéCLAD - Certified LabVIEW Associate Developer

  • RELEVANCY SCORE 2.81

    DB:2.81:50us Pulse With Usb 6501 9z



    I am trying to use a USB6501 in an application that requires creating a 50us pulse. I tried creating a loop with a simple inverting function and shift registers to create a pulse train but when I looked at the signal on an oscilloscope the pulse width was only 7ms. Is it possible to get a 50u pulse?

    DB:2.81:50us Pulse With Usb 6501 9z


    I try not to give specific hardware recomendations. You can contact your local NI Sales Engineer where you can provide more details (i.e. number of lines, etc.). You would want a card that has either a counter that can be configured to output a pulse or a card with hardware timed digital i/o.

  • RELEVANCY SCORE 2.81

    DB:2.81:How To Set Up A Analogue To Digital Convertion With Crio 9004 pz


    How to create a basic analogue to digital convertoin with compact rio?

    DB:2.81:How To Set Up A Analogue To Digital Convertion With Crio 9004 pz


    Dennis, the DAQmx driver is not compatable with a cRIO. We need to use the NI RIO driver to get data from the modules using Scan Mode or custom FPGA and Real Time code.

    There are module Specific exmaples for each module in the NI Example Finder (Help»Find Examples) (Hardware Input and Output»CompactRIO»Module Specific)

    Go to this page to learn more about DAQ with a cRIO.

  • RELEVANCY SCORE 2.81

    DB:2.81:No Volatge Analogue Out Actually 9p



    Dear sir,

    I have SCXI-1100 PCI-6221 SCXI-1180

    I would like to get analogue voltage out (i have 2 channels available), when I do that no voltage out from the SCXI-1180, in spite of the analogue input isOK and the digital I/O OK, but the analogue out is not ok, i don't know why?

    Thanks for your efforts.

    eyad

    automation engineer.

    DB:2.81:No Volatge Analogue Out Actually 9p


    Hi eyad,I have a couple more questions for you, that I forgot in my first post.

    - How are you generating the voltage? Are you using Measurement Automation Explorer (MAX)or a programming environment such as LabVIEW or Visual Studio? This will help me point you to an appropriate example.

    - If you have been testing the AO through some programming environment, let's take that out of the equation and use MAX. If you are not familiar with MAX, you can findit by going to Start»Programs»National Instruments. Locateyour device under Devices and Interfaces. Right-click on the device and chooseTest Panels. In MAX, you can choose to generate either a DC voltage or a sine wave. It would also be beneficial to test both AO channels. I assume when you say "no voltage out", you mean 0 volts correct?




    Rod T.

  • RELEVANCY SCORE 2.80

    DB:2.80:How To Count "Generate Pulse Train" Pulses pm


    hi!i´ve got an pci-mio-16e4 plus scb68 connector block. what i want dodo is, to count the pulses generated by the daq-vi "generate pulse train"which puts a ttl puls train signal on the gpctr-out pin.the problem is, that if i connect that pulse signal to an counter input,the pulse train will somehow disappear.can someone give me an hint how to count that kind of pulse train pulses?thnx + best regardsholger

    DB:2.80:How To Count "Generate Pulse Train" Pulses pm

    Hi Holger,The best way to perform your couter operations is by adapting the shipping examples in LabVIEW. These examples will typically be found under the Help menu (Find Examples... Hardware Input and Output DAQ Counters DAQ-STC). What I would suggest is opening the example Count Edges (DAQ-STC).vi and setting the Source Specification to be Misc 'other counter TC'. This will effectively internally route the output of the other counter to the source of this counter. That is typically how you would route the output of one counter to another.As for why your pulse train is disappearing, it wouldn't disappear unless you connect it to another signal that is perhaps driving a GND or high signal. You might have also connected it to the gate and in your program you didn't configure the gate to be a PFI line so by default it would ground the gate.Anyway, the key is that you have to explicitly specify that you want a signal from a PFI line to be represented on the gate or source or output of a counter. Using the method described in my first paragraph should do the trick though. Have a good day.Ron

  • RELEVANCY SCORE 2.80

    DB:2.80:Generating Pulse Based On Pulse Width 9a


    Can anyone tell me how to send out a signal based on letting the user choose pulse width on the analog channel? I know you can do frequency and duty cycle and from those parameters your width is set, but I would much rather be able to allow the user to actually just pick what pulse width they want. Thanks for any input.

    DB:2.80:Generating Pulse Based On Pulse Width 9a

    Can anyone tell me how to send out a signal based on letting the user choose pulse width on the analog channel? I know you can do frequency and duty cycle and from those parameters your width is set, but I would much rather be able to allow the user to actually just pick what pulse width they want. Thanks for any input.

  • RELEVANCY SCORE 2.80

    DB:2.80:Encoder Angle Vs Analogue Inputs fj



    I have a 8 way cDAQ9188 chassis and an array of input cards.

    9213

    9401 x 2

    9205

    9217 x 2

    9203

    9237

    I using one of the 9401 cards to input a 1024 pulse/rev encoder (A,B 0). The remaining 9401 supplies a timing pulse to this encoder card. I've had this all working with an encoder only program on the bench and the A,B and 0 work fine converting to 0-360 degrees when the encoder is operated by had, I haven't as yet tried logging at a faster rate when the encoder is back on the motor it came from.

    My main issue is I've an array of torque, pressure inputs and flow rates I need to reference against my compressors angle. Every time I seem to try and up the sample rate I get errors flagging up when I use a combined analogue inputs and encoder program.

    I'm assuming all the timing functions for each card need to tie up ?

    Do I need more timing inputs from one of my 9401 modules to each analogue card to give them a reference pulse to sample from as they don't seem to sample quick enough.

    Any help appreciated as I'm relatively new to all this having converted over from DasyLab.

    Can anybody also tell me how fast I can log using signal express and my setup ?

    Thanks

    Carl

    DB:2.80:Encoder Angle Vs Analogue Inputs fj


    You could use 1 sample on demand alongside some triggering in your code, Alongside this it would be a good idea to synchronise your inputs. The examples discuss particular pieces of hardware but will still be relevant to your application:

    Triggering: http://digital.ni.com/public.nsf/allkb/9248D61E22C​5C7C586257665005C081E

    Synchronisation: http://digital.ni.com/public.nsf/allkb/FA505A35F1D​9173286256F3A00663460

    Best Regards,

    Andrew




    Applications Engineer

  • RELEVANCY SCORE 2.80

    DB:2.80:Pulse Width Modulation Signal Generation For Ulx 77



    Hello,

    I am trying to produce an analogue waveform (i.e square wave) with an option to control the duty cycle.

    I am outputting through a Measurement Computing card, which uses the ULx user libaries.

    There are many examples to do what I want using DAQmx, but all those using ULx have no option to control the duty cycle.

    Can anyone help?

    Thanks in advance.







    Solved!
    Go to Solution.

  • RELEVANCY SCORE 2.80

    DB:2.80:Is Analogue Much Worse Than Digital ? xs


    Can you actually hear the difference between an analogue signal and a digital signal ?

    What type of cable/output is optimal for perfect sound quality ? Optical ?

    DB:2.80:Is Analogue Much Worse Than Digital ? xs

    I know that you have heard about parasit inductivity and capacity of a cable and the influence of that compared to the input impedance (resistence) of the amplifier and output impedance of the soundcard. In the analog world, a long cable is a filter. A mini jack is a cross-over device that leaks signal interchannels. With some parasit capacitors also.

    The DAC's in a digital receiver are usually better than the ones on the sound card.

    The interior of a PC is a noisy medium (electrical noise) and keeping the analog signal out of that medium is only benefic.

    The only reasons why Creative would still push analog on their cards is:

    . The enormous mass of cheap PC speaker system existing. And people that can be convinced that the only thing that their crappy sistem needs in order to sound great is a 24bit/96kHz sound card with 20dB SNR.

    2. The failure to impose the 3x SPDIF standard for uncompressed surround digital is make them to ignore the xSPDIF compressed soulutions.

    3. Some DVD-A antipiracy restrictions that impose that hi-res sound to be played analog only.
    Message Edited by SoNic2367 on 04-30-2006 08:48 PM

  • RELEVANCY SCORE 2.79

    DB:2.79:Dc Motor Control ms



    I have having a issue with pulsing a signal from encoder.. I have to control a motor making sure it doesn't go over a certain threshold. It needs to count the pulse with an have a repeat trigger. I have done code for it over an over but I do not know how to get this pulse signal.. It seems simple enough but I no longer no where to being.







    Solved!
    Go to Solution.

    DB:2.79:Dc Motor Control ms


    Hi Gotti_uncc

    If you are going to use a cRIO or a myRIO you will not be able to use the DAQmx API as this API is for a windows operating system.

    With a cRIO or a myRIO you will be able to use the FPGA and in the following link there is information about how to use an encoder and this other links has information about how to create a PWM signal in the FPGA.

    Regards

    Esteban R.

  • RELEVANCY SCORE 2.78

    DB:2.78:When Analogue Goes? 18



    Wondered if when the analogue signal goes in April, some channels will be no more, so will for example BBC1 101 disappear, or will BBC1 HD move to 101? Sky could use the opportunity to make the EPG and channel numbering make more sense and easier to use.




    geo136

    DB:2.78:When Analogue Goes? 18


    Yes it's all about money. BBC can't afford it with the licence fee frozen. But it is not that long ago that there was this new thing called Digital Television and Freeview??, so with technology progressing so quickly, give it a couple of years and you won't need a box anymore. No, you will store downloaded programmes in the unlimmeted cloud and you will pay sky for aceessto programmes/stations. With Sky moving into wi-fi in 2012this is the future, be prepared for news in I guess two years.




    geo136

  • RELEVANCY SCORE 2.77

    DB:2.77:Pulse Doesnt Allow Hdmi Surround dk



    Pulse used to be able to enable 5.1 playback (over HDMI or analogue jacks) simply by setting the number of channels to 6. This, however, no longer seems to work. The fault seems to be caused by Pulse somehow misdetecting my audio device, because a
    speaker-test -c6 -Dhw:0,3

  • RELEVANCY SCORE 2.77

    DB:2.77:Pulse Width Reduction a8



    I have a square wave/pulse train (1d array). I want to reduce the pulse width. Please see the figure. Here, the green line shows the falling edge of the reduced pulse I want to create from the longer width pulse. Pleae suggest a solution










    Attachments:







    untitled.PNG ‏13 KB

    DB:2.77:Pulse Width Reduction a8


    I have a square wave/pulse train (1d array). I want to reduce the pulse width. Please see the figure. Here, the green line shows the falling edge of the reduced pulse I want to create from the longer width pulse. Pleae suggest a solution










    Attachments:







    untitled.PNG ‏13 KB

  • RELEVANCY SCORE 2.77

    DB:2.77:Count Pulses And Generate One Pulse All Of 30 Period ck


    Hi'I need some help ... Spec: LabVIEW 7.1DaqmxNI PCI 6602I use one counter to generate a TTL signal (freq 10kHz)On another counter, I want to count the rising edgesand all of 30 periods, on a third counter, I want to generate one pulse ...I have a problem with the count of pulses ... Thank you for your help

    DB:2.77:Count Pulses And Generate One Pulse All Of 30 Period ck

    Duplicated thread.



    .mrLeft{float:left} .mrInfo{border-left:solid 1px #989898;font-size:x-small;color:#989898}Mathieu R.
    CTD - Certified TestStand Developer / Développeur TestStand CertifiéCLAD - Certified LabVIEW Associate Developer

  • RELEVANCY SCORE 2.76

    DB:2.76:Pulse Counter 8x



    How can I generate a pulse counter in labview (square wave generated from "signal generator")?

    basically, it should add 1 (+1) to the total for every pulse generated

    DB:2.76:Pulse Counter 8x


    If you have a hardware timer you can use this

    http://niweb.natinst.com/confluence/display/MIOPSE/Count+Digital+Events.vi




    Peter C.Applications EngineerNational Instruments

  • RELEVANCY SCORE 2.76

    DB:2.76:How Would I Count Analog Dc Input Pulses And Measure The Pulse Width? 7x


    I have a pulse generator for a linear actuator that sends out 40 pulses per inch of actuator travel. The pulse width varies depending on the speed of the actuator. The step pulse signal is from a low-voltage DC source and is being acquired using a Measurement Computing Minilab 1008 USB interface.1. I need to count the number of pulses per second to find the extension and speed of the actuator.2. The actuator will be pushing an object on a circular path, and we need this object needs to have constant angular velocity. Therefore I need to take this linear speed and vary it according to an equation such that it can produce a constant angular speed.3. Knowing how the actuator speed varies with voltage, I need labview to send a voltage signal out through the minilab module, through an amplifier, which will then give the actuator a new linear speed.Any ideas on how to accomplish this in labview?Thanks for any help you can offer.Emmanuel

    DB:2.76:How Would I Count Analog Dc Input Pulses And Measure The Pulse Width? 7x

    Emmanuel,

    First of all, MCC supports their own line of DAQ products. You should
    be able to find more useful information from their website. As you can
    see on the product page for the miniLAB 1008,
    you need to use their Universal Library for LabVIEW in order to
    communicate with this device. If you use this library to acquire an
    analog waveform, you can then use the "Pulse Measurements.vi" in
    LabVIEW to determine the pulse width. You could also write your own
    algorithm to count the number of rising edges in the signal. If you
    need more help with how to do this, please visit the LabVIEW forum.

    Another option to consider is that if you had hardware with fully
    functional counter/timers, you could use the hardware itself to count
    the rising edges and measure the pulse width of your signal. For
    example, you could use the PCI-6220 Low-Cost M-Series DAQ board for
    your application. It has two counter timers just like the rest of the
    multifunction DAQ boards. Using the DAQmx driver, you could configure
    one counter to do event or edge counting and the second counter to do
    pulse width measurements.

    Hopefully this information helps.

    Regards,

  • RELEVANCY SCORE 2.76

    DB:2.76:Calculating Pulse Width From Parallel Port dd


    Hi,

    I have a problem, I don't know how to counter.
    I have some piece of hardware that sends a High/low signal to my parallel port. It's a pulse width signal.
    The signal is just low, with every 20ms a high. The high is between 1 and 2 ms long. and that length determines my signal.
    Now I want to make a java progrma which shows realtime (refreshing every 0.5 sec or so) the length of my pulse in a graph.
    Is this possible, and if so, could anyone give me a direction to look at.

    I was thinking of letting a nanoTimer count while the signal is high, and use this as my output. But I don't know if this is accurate/possible.

    Thank you in advance,
    Kevin Lamers

    Edited by: kevinlamers on Jun 20, 2009 12:41 PM

    Edited by: kevinlamers on Jun 20, 2009 12:41 PM

    DB:2.76:Calculating Pulse Width From Parallel Port dd

    kevinlamers wrote:
    Is there no one out there who can help me?Difficult to say but I doubt it. I suspect you will need some C code accessed through JNI.

  • RELEVANCY SCORE 2.75

    DB:2.75:Flow Meter And With Ni Usb-6210 And Labview Signalexpress dm



    Dear,

    I am using a flow meter (manufacturer Omega, model FPR-303), NI USB-6210 and Labview SignalExpress.

    The flow meter has three cables: red, white and black.

    According of the Omega, the red is the sensor power supply (5-24 V DC and 2 mA current), white is the signal and black is a ground. The sensor`s output is current sinking pulse (6-24 Vdc) and the sensor output can be a sinking or sourcing pulse and the pulse production by flow meter is a continuous pulse.

    My plan was use the NI USB-6210 to count the edge or frequency pulse and to determination the flow according with factor-k that i obtained by manufacturer.

    I read the USB-6210`s manual and connected the red in +5V, white in FPI 0 for crt0 and black in DGND, all of the wires in Digital I/O side.

    In Labview SignalExpress, i did: Connected the NI USB Add step Adquire Signal DAQmx Adquire Counter Input Edge Count. I choose the falling active edge and Sample On Demand.

    I have tested the NI USB-6210 and flow meter, but i do not have success.

    My questions are:

    1) Is NI USB-6210 applicable in this case? If it is not, please, tell me the appropriate equipment.

    2) How I connect the cables, is it correct?

    2) Does NI USB-6210 take a sinking or sourcing pulse signal?

    3) Does NI USB-6210 take continuous pulse signal?

    4) In this case, do you recommend the edge count or frequency count?

    Omega answer me that i can use the NI USB-6210, then i need by other Omega`s equipment to use with NI USB-6210.

    Regards

    Tallita Nunes










    Attachments:






    Omega_FRP_300_Manual.pdf ‏803 KB

    DB:2.75:Flow Meter And With Ni Usb-6210 And Labview Signalexpress dm


    Tallita Nunes,

    In typical Omega fashion the electrical output is very poorly specified. After doing a little reading between the lines, it appears that the output is generated by an open collector NPN transistor with the emitter connected to ground. At minimum you will need a pull up resistor to +5 V. The USB-6210 has in internal pull down resistor of ~47000 ohms. So thepull up resistor should be no larger than 1/10 of that. The lower limit is set by the current sinking capabillity of the sensor (which Omega does not specify). Figure 2 of the manual you posted shows a 2200 ohm resistor used with a 24 V power supply. The current in thatis just under 11 mA. At 5 V a 470 ohm resistor would provide similar current.

    Next. NI does not specify a rise time for timing input signals on the USB-6210. Open collector sensors can have rather slow rise times (by digial logic standards). The debounce filter settings may allow the device to tolerate slow input signals. The 2.56 ms filter is too slow for the upper end of the flow rate. Try the 6.425 us filter setting. If you see spurious counts (or no counts at all) you will probably need to add a Schmidt trigger between the sensor and the DAQ device.

    Lynn

  • RELEVANCY SCORE 2.75

    DB:2.75:Can Daq 6035e,Or 6024e Used To Count Pulse Train 97


    i need to count two digital pulse train coming from an encoder, whose frequency keeps changing. the encoder is a typical feed back from servomotor

    DB:2.75:Can Daq 6035e,Or 6024e Used To Count Pulse Train 97

    Hi,Both of those DAQ boards can measure digital pulse train frequencies using the counters. These cards can support 2-pulse encoder measurements on DIO6 and DIO7. This means that if there is a rising edge on Channel A the counter increments and a rising edge on Channel B decrements the count. You can also set the counter application for frequency measurement and that will measure the frequency of the pulse train on the line. These cards also have 2 such counters.There are many LabVIEW and CVI examples demonstrating this. If you search the site for position or encoder measurements there should be some example programs for you. Hope that helps.Ron

  • RELEVANCY SCORE 2.73

    DB:2.73:6009 Analogue To Digital Conversion 9s


    I am trying to take in an analogue signal and convert it to digital. Once this is done i have to measure the pulse width of this digital signal. This all has to be done in low level programming mxBase because i am using the USB 6009 DAQ card which has no DAQ assistant software available yet

    DB:2.73:6009 Analogue To Digital Conversion 9s

    Hi Dave_Wex, you're actually talking about an algorithm to interrogate the analog acquired signal and find out a pulse width.There's a couple of ways to do this.First, timing is the key. Open up one of the analog input examples, and you can then take the signal acquired, search it for values where it first goes over the 2.5V mark, and then for the first time it drops back below.A possible algorithm in LV 7.1 is below.This requires at least 2 pulses to work for the top algorithm, one pulse for the second algorith (only works with a single pulse acquired), and only analyses the first pulse fpr the bottom algorithmPlease let me know if that helpsSacha EmeryNational Instruments (UK)



    // it takes almost no time to rate an answer

  • RELEVANCY SCORE 2.73

    DB:2.73:How To Take In An Analogue Signal And Discard The Data Which Is Not Required From The Signal 1a


    I am using Labview to take in two signals from a DAQmx board. I am taking in a analogue signal from a sensor and also a quick on/off pulse from the sensor as well. I have the DAQ express VI taking in both the signals and combining them into one.I am creating an image from the data via a reshape array, although the data which is going to the image is full of samples which i dont need and i need to be able to use the samples between the start pulse going on and off again. So how do i take lots of data but only use part of it, can i use a basic subtract function on it or .....?

    Thanks

    C Lees

    DB:2.73:How To Take In An Analogue Signal And Discard The Data Which Is Not Required From The Signal 1a

    Here you go Dev

    Message Edited by SarahB on 08-16-2006 06:20 AM




    SarahApplications Engineer | National Instruments | UK Ireland

  • RELEVANCY SCORE 2.73

    DB:2.73:Pulse Out For Every Nth Pulse In Using 6024e Counter? j9


    Is it possible to get (continuously)a pulse out of the 6024E counters for every Nth pulse of an external signal going to the source pin? A VI and the description of the connections will be appreciated.appreciated



    Scientia est potentia!

    DB:2.73:Pulse Out For Every Nth Pulse In Using 6024e Counter? j9

    Hi magvar,Depending on your application development environment (ADE) API (LabVIEW, CVI, VC++ etc.) you will want to configure the counter for continuous pulse generation. There are two pulse specs that you have to configue. The first configures the delay in number of edges of your source and the second configures the width of your pulse. Therefore if you set pulse spec (ND_COUNT in C code) 'A' to N/2 and pulse spec 'B' to N/2 then your pulse train will output a pulse every Nth pulse on the source. Each ADE will have a shipping example that demonstrates this configuration. These examples ship with NI-DAQ and can be found in the NI-DAQ folder of National Instruments unless it is LabVIEW or CVI in which case it should be in their respective directories. Hope that helps. Have a good day.Ron









    Attachments:







    TIOgenSquareWave.C ‏6 KB

  • RELEVANCY SCORE 2.73

    DB:2.73:Daqmx Frequency Measurement And Pulse Count x1



    Hi all,

    I want to measure frequency with my DAQ card, and it doesn´t work.

    I have attached two screenshots of my VIenerate a 1kHz signal onctr1, and...

    ... if I count the pulses, it wors, the READ vi gives me the number of pulses since start of the task

    ... if I measure the frequency of this signal, the READ vi runs always in timeout.

    The idea how I build my application is from an example VI from NI.

    My question is, how to ge measurement values when I measure frequency?










    Attachments:







    CountPulses.JPG ‏45 KB

    DB:2.73:Daqmx Frequency Measurement And Pulse Count x1

    ...of course there is a bridge between ctr1_out and ctr0_in.

  • RELEVANCY SCORE 2.73

    DB:2.73:Rising Edge Phase Shift 1c



    Hi

    I am using a CDAQ 9178 and have a 9229 analogue card. I have two 28V square waves that are aroudn 90 degrees sperated. The frequency is around 10-20hz. I am sampling at 10000 samples per second and recording 20000 samples of data. so two seconds.

    How can i measure phase shift between the two rising edges for every pulse.

    I am using the 9229 analogue card as it can handle the higher voltage plus all channels are sampled simultaneous

    I have attahced my programme.










    Attachments:







    signal analysis.vi ‏185 KB

    DB:2.73:Rising Edge Phase Shift 1c


    Hi JWinstanley,

    You can measure the phase shift by measuring the time difference between rising edges of each signal.

    I have attached a document which may be of use to you:http://www.ni.com/white-paper/4529/en/

    Best of luck!

    SFuller

  • RELEVANCY SCORE 2.72

    DB:2.72:Buffered Digital Events Counter Using Sample Clock Source mj


    Hi

    I am using visual studio c# with daqmx .net class library and my device is USB-6363

    I want to make a program that count buffered digital events using sample clock source.

    Counting buffered digital events and Generating sample clock source are conducted in same device (USB-6363).

    I wrote code as below.

    Task TaskPulseGen = new Task();
    Task TaskCounter = new Task();

    try
    {
    int NumData = 10;
    int NumCounterRead = 0;
    double Rate = 10;

    // Setting Pulse Generation Task
    COChannel ChannelPulseGen = TaskPulseGen.COChannels.CreatePulseChannelFrequency("Dev1/ctr0", "Pulse Generation", COPulseFrequencyUnits.Hertz, COPulseIdleState.Low, 0, Rate, 0.5);
    ChannelPulseGen.PulseTerminal = "/Dev1/PFI10";
    TaskPulseGen.Timing.ConfigureImplicit(SampleQuantityMode.FiniteSamples, NumData);

    // Setting Count Task
    uint[] DataCounter = new uint[NumData];
    CIChannel ChannelCounter = TaskCounter.CIChannels.CreateCountEdgesChannel("/Dev1/ctr1", "", CICountEdgesActiveEdge.Rising, 0, CICountEdgesCountDirection.Up);
    ChannelCounter.CountEdgesTerminal = "/Dev1/PFI0";
    TaskCounter.Timing.ConfigureSampleClock("/Dev1/PFI10", Rate, SampleClockActiveEdge.Rising, SampleQuantityMode.FiniteSamples);
    TaskCounter.Stream.Timeout = 5000;
    CounterReader ReaderCounter = new CounterReader(TaskCounter.Stream);

    // Task Start
    ReaderCounter.MemoryOptimizedReadMultiSampleUInt32(NumData, ref DataCounter, out NumCounterRead); // Wait for the 10 sample clocks (Timeout occur)
    TaskPulseGen.Start(); // Genrate 10 Pulse signals (Sample clocks)

    Console.WriteLine("Data");
    for (int i = 0; i NumData; i++)
    {
    Console.WriteLine("Buff {0} : {1}",i, DataCounter[i]);
    }

    }

    catch (DaqException exception)
    {
    Console.WriteLine(exception.Message);
    TaskPulseGen.Dispose();
    TaskCounter.Dispose();
    }

    Finite pulses are generated, and counter has same number of buffer with pulses.

    When program is started, It is stoped at “MemoryOptimizedReadMultiSampleUInt32”.

    Because “MemoryOptimizedReadMultiSampleUInt32” is wait for getting pulse signal. So it can’t be continued to implement code.

    I have tried using thread to solve this problem. I put “MemoryOptimizedReadMultiSampleUInt32” on other thread, and it can continue to implement code.

    But it has risk. When pulse generation task is excuted first before count task is ready to get pulse signal, Counter missed some pulse signal. And it makes same problem.

    Is there any solution for this problem?

    Please help me.

    Thanks!

    DB:2.72:Buffered Digital Events Counter Using Sample Clock Source mj

    Hi

    I am using visual studio c# with daqmx .net class library and my device is USB-6363

    I want to make a program that count buffered digital events using sample clock source.

    Counting buffered digital events and Generating sample clock source are conducted in same device (USB-6363).

    I wrote code as below.

    Task TaskPulseGen = new Task();
    Task TaskCounter = new Task();

    try
    {
    int NumData = 10;
    int NumCounterRead = 0;
    double Rate = 10;

    // Setting Pulse Generation Task
    COChannel ChannelPulseGen = TaskPulseGen.COChannels.CreatePulseChannelFrequency("Dev1/ctr0", "Pulse Generation", COPulseFrequencyUnits.Hertz, COPulseIdleState.Low, 0, Rate, 0.5);
    ChannelPulseGen.PulseTerminal = "/Dev1/PFI10";
    TaskPulseGen.Timing.ConfigureImplicit(SampleQuantityMode.FiniteSamples, NumData);

    // Setting Count Task
    uint[] DataCounter = new uint[NumData];
    CIChannel ChannelCounter = TaskCounter.CIChannels.CreateCountEdgesChannel("/Dev1/ctr1", "", CICountEdgesActiveEdge.Rising, 0, CICountEdgesCountDirection.Up);
    ChannelCounter.CountEdgesTerminal = "/Dev1/PFI0";
    TaskCounter.Timing.ConfigureSampleClock("/Dev1/PFI10", Rate, SampleClockActiveEdge.Rising, SampleQuantityMode.FiniteSamples);
    TaskCounter.Stream.Timeout = 5000;
    CounterReader ReaderCounter = new CounterReader(TaskCounter.Stream);

    // Task Start
    ReaderCounter.MemoryOptimizedReadMultiSampleUInt32(NumData, ref DataCounter, out NumCounterRead); // Wait for the 10 sample clocks (Timeout occur)
    TaskPulseGen.Start(); // Genrate 10 Pulse signals (Sample clocks)

    Console.WriteLine("Data");
    for (int i = 0; i NumData; i++)
    {
    Console.WriteLine("Buff {0} : {1}",i, DataCounter[i]);
    }

    }

    catch (DaqException exception)
    {
    Console.WriteLine(exception.Message);
    TaskPulseGen.Dispose();
    TaskCounter.Dispose();
    }

    Finite pulses are generated, and counter has same number of buffer with pulses.

    When program is started, It is stoped at “MemoryOptimizedReadMultiSampleUInt32”.

    Because “MemoryOptimizedReadMultiSampleUInt32” is wait for getting pulse signal. So it can’t be continued to implement code.

    I have tried using thread to solve this problem. I put “MemoryOptimizedReadMultiSampleUInt32” on other thread, and it can continue to implement code.

    But it has risk. When pulse generation task is excuted first before count task is ready to get pulse signal, Counter missed some pulse signal. And it makes same problem.

    Is there any solution for this problem?

    Please help me.

    Thanks!

  • RELEVANCY SCORE 2.72

    DB:2.72:Motu Ultralite No Output Of Analogue Signal ax


    Essentially I am not able to output an analogue signal from the ultralite. For example if I input a signal from a macbook via the ultralite, I see the level on the ultrlalite and hear it on the headphones, however the signal is not being sent to the analogue outs. I am able to input an analogue signal just fine and receive the signal via the ultralite to logic on the macbook pro.

    Thanks in advance.

    DB:2.72:Motu Ultralite No Output Of Analogue Signal ax

    cigame2,

    I tried your recommendation today, however the condition still exists. I believe that the issue maybe is with the motu itself (or a setting), as the result is the same if I use it in stand alone mode.

    Geoff

  • RELEVANCY SCORE 2.72

    DB:2.72:Counting Ttl Pulses At High Speed ff


    Hi all,

    I am using PCI-6221 board with DAQmx to count the number of TTL pulses (which varies in its frequency between 0Hz to 10MHz)at a high speed (200,000 samples/sec.) and I am having a problem when the TTL pulse frequency drops below a certain level.

    I am using CTR0 to generate continuous pulse train at 200kHz frequency to feed to CTR1 Gate input. I verified that the pulse train is being generated fine.

    I am using CRT1 with buffered counting to collect the count for 200,000 samples at a time (duration of 1 sec.). I got the example code (Cnt-Buf-Cont-ExtClk) and pretty much used it as is.

    CTR1 Gate is coming from CTR0 Out, which is 200kHz pulse train with 50% duty cycle, and CTR1 Source is the TTL signal that I am trying to count. At first, I thought that everything was working fine with the Source signal being at around 5MHz. Then, when I had the Source signal down below about 300kHz, I noticed that the program is taking longer than 1 sec. to collect the same 200k samples. Then, when I got the Source signal down to 0Hz, the program timed out.

    I am guessing that somehow the counter is not reading for the next sample when there has been no change to the count, but I cannot figure out why and how.

    Any information on this and a way to get around would be greatly appreciated.

    Kwang

    DB:2.72:Counting Ttl Pulses At High Speed ff


    Dear Paul,

    I tried your suggestion and it works!

    Thank you for your help.

    Kwang

  • RELEVANCY SCORE 2.71

    DB:2.71:Vhdl Counter Not Incrementing In Simulation sf



    Hi,

    I am using the code in the following link

    http://web.cecs.pdx.edu/~mperkows/CLASS_VHDL_99/SQ​UARE_ROOT/counter.vhd

    and I am simulating it using ISim. I have given the values for clock as in the appended image below

    I have first set "Rst_n" to 0 then as per the code "count" gets the value of 0. Then in the following clock pulse I have set the "Rst_n" signal to 1, "IncrCnt" signal to 1 so the "count" should start incrementing but it doesn't. the signal "count" is remaining 0. Can someone point out why "count" is not incrementing? I have also tried by putting "count" in the sensitivity list of the process but that too is not incrementing the count. Please help.

    Best Regards,

    Koyel







    Solved!
    Go to Solution.

    DB:2.71:Vhdl Counter Not Incrementing In Simulation sf

    Dear Pratham,You are right. I checked and saw that I didn't set "Rst_n" to 1. After setting it to 1, it works as expected. Thanks again.Best Regards,Koyel

  • RELEVANCY SCORE 2.71

    DB:2.71:Using Two Counters: One For Regenerable Pulse Generation, One As A Counter 7c



    I am new to use counters. I am using a NI PCI-6110 multifunction DAQ card. I want to count a digital pulse input (to the PFI 2 connector) , and also using the input to trigger another counter to generate pulses. So, I configured the first counter (task 1) to generate digital pulses with PFI2 as trigger source and retriggerable attribution; andconfigured the other counter (task 2) to count the number of edges of the digital signal with .... But after the two tasks started, the first task generated an error 50103 (Possible reason(s): NI Platform Services: The specified resource is reserved. The operation could not be completed as specified.) Attached is the block diagram. Thanks.







    Solved!
    Go to Solution.

    DB:2.71:Using Two Counters: One For Regenerable Pulse Generation, One As A Counter 7c


    Your board uses the very-old-by-electronics-standards DAQ-STC counter chip which kinda secretly requires *both* counters working together to make a finite pulse train. It's not actually secret if you read the right parts of the right docs, but it's not hard to miss if you don't know you should be looking. It's been quite a while since I did much with those counters, but I have this nagging thought that they may not support retriggerable finite pulse train generation at all. I'd caution you to at least double-check this.

    Anyway, that's the reason for the error. The finite pulse generation task uses not only the counter you specify but it also needs the other one to help it. A couple newer generations of counter chip (NI-TIO, DAQ-STC2) continued to have this same limitation, but the *most* recent one no longer does.

    The X-series boards use the "NI-STC3" chip which give you 4 user-programmable counters instead of 2, *AND* each one can generate finite pulse trains without using a helper counter. You may want to pair one of these up with your 6110, assuming you need the 6110's simultaneous analog sampling capabilities.

    -Kevin P

  • RELEVANCY SCORE 2.71

    DB:2.71:Pci 6251 Configureanalogedgetrigger z9


    Hello,

    I try to start a measurement on a analog signal. This signal is a positive pulse. When it arrives, i start to count until the signal on "ctr0" arrives.

    So i try to configure a analogTrigger on APFI0. But the following error occurs :

    "Specified property is not supported by the device or is not applicable to the task
    Property : CNiDAQmxStartTrigger::type
    Task Name : BancDeTest

    Status Code : -200452

    Any one can help me ?

    Thank you.

    I've attached two files









    Attachments:







    DAQmxTaskTempsDetection.cpp ‏6 KB

    DB:2.71:Pci 6251 Configureanalogedgetrigger z9

    Hello,

    I try to start a measurement on a analog signal. This signal is a positive pulse. When it arrives, i start to count until the signal on "ctr0" arrives.

    So i try to configure a analogTrigger on APFI0. But the following error occurs :

    "Specified property is not supported by the device or is not applicable to the task
    Property : CNiDAQmxStartTrigger::type
    Task Name : BancDeTest

    Status Code : -200452

    Any one can help me ?

    Thank you.

    I've attached two files









    Attachments:







    DAQmxTaskTempsDetection.cpp ‏6 KB

  • RELEVANCY SCORE 2.71

    DB:2.71:Pulse Edge Counter Vi Too Slow? 1d



    Hi everyone,

    I'm trying to write a VI based off of one described here that counts the number of rising pulse edges from an external function generator with a frequency of 7.7KHz using the USB 6211 DAQ.

    The function generator is plugged into Ctr 0 in the DAQ. A pulse train with user defined parameters at Ctr 1 is used to buffer the input signal. Ideally, I want the VI to count and sum the number of pulse edges. When the count reaches an arbitrary number (i.e. count = 256), it should reset the count and add one to a separate count to keep track of the number of "resets."

    The pulse train I'm using to buffer the 7.7KHz input has the parameters of 16KHz, a duty cycle of 0.50, and an idle state of low.

    The problem with my VI is that the count numbers doesn't match the frequency of the input signal. Running the VI for 10 seconds should give back a "reset" count around 300 based on the input frequency. But in actuality, I'm seeing only around 100. I am sure that this is not a hardware issue since running the example Count Digital Events.vi returns an accurate count. Running my VI in the highlight execution mode returns an Error -200279.

    I attached the VI that I'm currently working on using LabVIEW version 8.0. I would appreciate any input.

    Thank you for your time,

    admlam










    Attachments:






    BufferedCounting256.vi ‏48 KB

    DB:2.71:Pulse Edge Counter Vi Too Slow? 1d


    Hi christineeun,

    Here is an image of the code:




    Regards,Jim Schwartz

  • RELEVANCY SCORE 2.71

    DB:2.71:Simultaneous Counter Output Input 8x



    Hello,

    I am working with a light detection device called and Avalance PhotoDiode,which emits a single TTL pulse for every photon detected. A gate signal sets the frequency that the photon count is reported.I am trying to write a program that--via an M-series USB-6229--simultaneously sets the gate frequency of the APD's gate and counts the device's output pulses.

    My plan was/is to use one of the counters to generate a continuous pulse train for the gate signal (~1K Hz), and the second counter to count the rising edges emitted. However, my current program quickly falls on it's face; and I am having trouble understanding the error messages.

    If someone could look over my program and offer advice, it would be greatly appreciated.

    Thanks,

    Ryan










    Attachments:







    APD DAQ 2.vi ‏118 KB

    DB:2.71:Simultaneous Counter Output Input 8x


    Hi smosit,

    What error messages / codes are you experiencing? This may help the troubleshooting. Thanks.




    DavidApplications EngineerNational InstrumentsDigital Multimeters

  • RELEVANCY SCORE 2.71

    DB:2.71:Pulse Width Of The Last Pulse pz



    Hi,

    I am trying to measure the pulse width of a input signal. I can't use the counter. The input signal is coming on analog or digital input channels.

    The input signal has pulses varying from 3-4, and I am interesed in finding the pulse width of the last pulse.

    I tried to use the block Pulse Measurements VI but it does not give me data for the last pulse. Because it needs to compare the mid level of two signal in the same direction, which is not available if i measure the last pulse.

    Would be nice if someone can help me out..

    Regards,

    DB:2.71:Pulse Width Of The Last Pulse pz


    Hi,

    What kind of data do you want to analyze? Is it data already available on your PC, or are you measuring? Which hardware?

    If you would measure the signal as a wavefrm, you can use Pulse Measurements VI to measure the pulse width. In case there are multiple pulses, you can force it to look at a specific pulse by wiring a number topulse number. Have a look at the help of that VI:

    http://zone.ni.com/reference/en-XX/help/371361K-01/lvwave/pulse_measurements/

    If the number of pulses is varying, you might want to use this vi in a while loop.

    Is this of any help?

  • RELEVANCY SCORE 2.69

    DB:2.69:Starting Stopping A Digital Trig Analogue Aquisition xd


    I would like to start a digitally triggered Analogue Acquisition and then on the next digital pulse end the Acquisition which then stores the analogue data including the frequency of the two pulses.I would appreciate any help or guidance. As you can tell I�m still a very new user to LabVIEW. I have only just finished Data Acquisition Sig. Cond. Manual and still feel that I�ve only scratched the surface in solving my application for this software.

    DB:2.69:Starting Stopping A Digital Trig Analogue Aquisition xd

    Thankyou for your reply unfortunatley i'm still only using LabVIEW 6.1. Can you please send me a 6.1 version of your download?ThanyouRichard.

  • RELEVANCY SCORE 2.69

    DB:2.69:Daqmx Trigger Start Delay Won't Delay Data Acquisition! am


    Hello all,

    I'm trying to trigger labview to take a finite number of samples from Ai0 based on an internally generated counter (CO Pulse Time).

    The sampling triggers perfectly well off the rising edge of the digital signal but although I've added a property node to control the start delay (delay before labview starts acquiring data) this has no effect on when Labview starts to acquire the .Am I using the property node incorrectly?

    Cheers,

    Bob

    I've attached my code.

    The bottom half is where the counter pulse time is generated and the top section is where acquisition from the Analogue input takes place. I linked the counter output to the analogue input so that I could check what delay I was adding. I should theoretically be able to delay the trigger so that Labview starts to acquire data after the ~5V counter pulse has stopped but this isn't the case. It always starts acquiring data immediately when triggered.










    Attachments:







    Labview code.vi ‏107 KB

  • RELEVANCY SCORE 2.69

    DB:2.69:How Do I Generate Analogue Signals? kz



    Hello All,

    I am trying to generate analogue signals to simulate valve position. I also want to simulate 0-5V valve position (analogue signal). I have implemented digital valve position using toggle switches but I would like to implement the analogue signals.

    Please help out.

    Thanks







    Solved!
    Go to Solution.

    DB:2.69:How Do I Generate Analogue Signals? kz

    You want to generate 2kHz signals with the 6009? If so, no you can't do that. Look at the specs.

  • RELEVANCY SCORE 2.69

    DB:2.69:I Want To Start And Stop Counters Using The Same Signal For My Project Please Help jk


    I am doing my undergrad project based on labview. I have to start and stop a counter based on a digital pulse i.e (0 to 1 transition starts counter and 1 to 0 stops) but the pulse duration is only about 0.2 mS.i nedd to exactly measure the pulse duration. But as hard as i try, the counter dosent function and i get an error saying counter is not a valid NI compatible device. Also i am using counter to count time and give 1000000Hz as time base to count in micro seconds. Will this count in Micro seconds?? or is it smaller than the resolution of the counter? please help

    DB:2.69:I Want To Start And Stop Counters Using The Same Signal For My Project Please Help jk

    Hi again,take a look at the example Count Time-Int(9513).vi in the counter example.You can find it also here:http://sine.ni.com/apps/we/niepd_web_display.DISPLAY_EPD4?p_guid=B45EACE3DBA156A4E034080020E74861p_node=DZ52327p_submitted=Np_rank=p_answer=p_source=ExternalGood luck,Alberto

  • RELEVANCY SCORE 2.69

    DB:2.69:Pci 6025e And External Trigger z3


    hi, I am using PCI 6025E to generate a Retriggerable Pulse on its Counter.
    I am using the external trigger pulse coming from an encoder as input
    on PFI1. I want a counter output which will be high for every 14th
    pulse and low
    for the remaining 13 pulses of the external trigger signal supplied.
    So, to generate the pulse on Counter 0, i am using the pulse specs(raw)
    control. It has controls: Delay (edge), pulse(edge) and timebase. Does
    the timing of external trigger decide the timebase and if yes then what
    value do i need to input in the "timebase" control. Then i guess i can
    decide the count of "Delay" and "Pulse" depend on the timebase.

    Please help.

    DB:2.69:Pci 6025e And External Trigger z3

    Hi,

    Well. i am new to Labview.So, how do i create a VI to demonstrate the
    error? Also, since we already had a PCI6025E in the lab, and i could
    use it for counter operations, i am just using the same instead of
    getting a new DAQmx.

    When i change the parameter to PFIn, it gives me the error 10123: Invalid paramID used.

    I am attaching my VI for reference. I am supplying the external
    trigger input at PFI1. I want to set the values for pulse
    specs(raw) such that the counter will generate a pulse every 14th pulse
    of my trigger input. So, i want to know what timebase it considers with
    a external trigger and what values i need to input in the pulse
    specs(raw) control.

    Pallavi.










    Attachments:







    daq-stc.llb ‏124 KB

  • RELEVANCY SCORE 2.69

    DB:2.69:Pulse Counter zc


    Hello,i need help again with a counter. I want to count a rectangular signal. I like to use the sync up/down counter, the 74193N, but i dont know how to root it. It would be nice, if someone could give me an example circuit. I thought, that the FreqCounter could do this operation, but its a bad tool. It dont count pulses, it only count the positive and negative slope of an signal...thats it









    Attachments:







    Zähler_Test.ms10 ‏96 KB

    DB:2.69:Pulse Counter zc

    One other thing I didn't mention that perhaps you have found, is that you must also have a power source for the digital parts also. Ground alone is not enough. Hope this didn't cause any confusion. I'm not familiar with the power and ground symbolic conventions your versionuses. Sorry.

  • RELEVANCY SCORE 2.69

    DB:2.69:Signal Level For Pulse Width Measurement d3



    Hello,

    I am measuring the pulse width with the M6251 by counter (CI Pulse Width)

    I understand that the digital input is working on TTL levels (0,8V low 2,4V high).

    Can it be exactly said at which signal level the pulse width is measured?

    Thanks,

    Ralf







    Solved!
    Go to Solution.

    DB:2.69:Signal Level For Pulse Width Measurement d3


    Ralf,

    If you need configurable levels, then you need to to an analog acquisition and then use Pulse Measurements.vi from the Signal Conditioning Waveform Measurements palette. Make sure you sample fast enough to get several sample during the transitions so that you can get reasonably accurate measurements. Digital acquisition by definition reduces the data to two levels - low and high.

    Lynn

  • RELEVANCY SCORE 2.69

    DB:2.69:Digital To Analogue Switchover sm



    I have an lcd analogue tv on an exercise machine will the tv work if the digital signal from the outside aerial and the dishsignal go into the sky box and then into the TV via a single lead into theexercise machine.

    DB:2.69:Digital To Analogue Switchover sm


    No I don't think it will as your TV has to have a digital tunner in it. For this to work you would need to buy something like a freeview box and connect it to the TV and then the aerial from the roof would be plugged into it.




    __________________________________________________________________________________________.

    If someone has helped you then please click on the LIKES button in their post.
    I do not work for Sky.

  • RELEVANCY SCORE 2.68

    DB:2.68:Ni 6602 How To Synchronize Frequency Counter 3k



    Hi, i'm working with a NI 6602 board. Actually we have 3 optical encoder connected to ctr0 (pfi38), crt1(PFI34) and ctr2(PFI30). I need to have synchronous acquisition of frequency. I'm using NI-DAQMX with C . Our goal is to display frequency variation between the 3 entry.

    I think using edge count can be a better way to have synched samples but actually i can't change wiring and cannot connect my source signal to pfi39, pfi35 and pfi31. I've tried to use DAQmxSetCICountEdgesTerm(taskHandle,"Dev2/ctr0","Dev2/PFI38") , i have the error -89120 (signal can't be routed). When i set DAQmxSetCICountEdgesTerm(taskHandle,"Dev2/ctr0source","Dev2/PFI38") no error but always count 0.

    My signal frequency is betwenn 0 and 16000hz.

    My code is below

    DAQmxErrChk (DAQmxCreateCOPulseChanTime(taskHandleOut, "Dev2/ctr4", // gating pulse generated "channel 1", DAQmx_Val_Seconds, // units DAQmx_Val_Low, // resting state 0.0, // initial delay 0.5, // pulse train freq 0., 0.5)); // pulse shapeDAQmxErrChk (DAQmxCfgImplicitTiming( taskHandleOut, DAQmx_Val_ContSamps, 0));

    DAQmxErrChk (DAQmxCreateCICountEdgesChan( taskHandle, "Dev2/ctr0", "channel 0", DAQmx_Val_Rising, 0, // initial count DAQmx_Val_CountUp)); // count directionDAQmxErrChk (DAQmxCfgSampClkTiming( taskHandle, "/Dev2/Ctr4InternalOutput", // sample clock set to pulse gen 20000000.0, // max expected rate of sample clock DAQmx_Val_Rising, DAQmx_Val_ContSamps, 10000000)); // buffer size DAQmxSetCICountEdgesTerm(taskHandle,"Dev2/ctr0source","Dev2/PFI38");

    Regards

    DB:2.68:Ni 6602 How To Synchronize Frequency Counter 3k


    Hi yipilipi,

    To make edge count, you need to put your signal on the counter sources pin. If not you will not get counts!

    Regards,





    Rémi D.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;} Les rencontres techniques de NI - Mesures et acquisition de données : de la théorie à la mise en ...

  • RELEVANCY SCORE 2.68

    DB:2.68:Triggering Analogue Input From Ttl Signal zs


    I am trying to acquire engine cylinder pressure data using LabVIEW and aPCI-6023E board.I want to acquire a single analogue voltage from ACH0 from a flywheelencoder which sends a TTL pulse each crank angle.The online help, etc. doesn't quite seem to get it right. I have tomanually adjust the sample rate to get it to acquire 360 samples perrevolution, i though this was the point of triggered acquisition not to haveto do this!!!Any help/example code would be appreciated. My email address is ttbrb atstudent.lboro.ac.ukThanks,Ben BrownLoughborough UniversityDepartment of Aeronautical and Automotive Engineering

    DB:2.68:Triggering Analogue Input From Ttl Signal zs

    I am trying to acquire engine cylinder pressure data using LabVIEW and aPCI-6023E board.I want to acquire a single analogue voltage from ACH0 from a flywheelencoder which sends a TTL pulse each crank angle.The online help, etc. doesn't quite seem to get it right. I have tomanually adjust the sample rate to get it to acquire 360 samples perrevolution, i though this was the point of triggered acquisition not to haveto do this!!!Any help/example code would be appreciated. My email address is ttbrb atstudent.lboro.ac.ukThanks,Ben BrownLoughborough UniversityDepartment of Aeronautical and Automotive Engineering

  • RELEVANCY SCORE 2.68

    DB:2.68:Digital Pulse Generation By External Analogue Input And Analogue Output Generation Timed By Generated Digital Pulse df



    Hi,

    This is what I want to do with PCIe-6353 card.

    Input: Differential Analogue Input (AI). The waveform itself is very similar to digital pulse train.

    Desired Outputs:

    1. Digital Pulse train (CO) triggered by AI.

    I want DAQmx to generate only one single pulse for one trigger. However, it is a continuous process.

    Please look at the following picture.

    The duration of one AI pulse is between 50 to 60 us and the time difference between AI pulses is also around 50 us.

    The duration of one CO pulse is 10 us.

    2. Analogue Output (AO) timed by CO.

    First, 1D or 2D DBL array will be generated depending on the number of output channels.

    The generated CO will be external clock for AO. For each CO pulse AO will change its value according to the array. Please, look at the following picture.

    I think once the first task (CO) is done, the second task (AO) will be achieved quite easily. My problem is I do not know where to start with the first task. Could anyone give advice or example codes to refer to?

    DB:2.68:Digital Pulse Generation By External Analogue Input And Analogue Output Generation Timed By Generated Digital Pulse df


    Hello KaiLeem,

    Thank you for using NI Forums.

    I found this example that I think will give you an idea about how to approach your solution.




    Mr.OApplications EngineerNational Instruments

  • RELEVANCY SCORE 2.68

    DB:2.68:Start A Counter From A Trigger m1


    Hello,
    I've a 6023EI'd like to :
    1) detect a trigger T1
    2) count N trigger T2
    3) generate a TTL (one pulse)
    loop to 1)

    So, I'm looking for a way to run a counter on a front edge of a signal T1 (fast and slim)Then, I've to count N front edge coming from T2 (very fast and slim)generate a TTL signal on a DIOreset the counter to zerothen loopThe best way to do that should be to arm a counter to a given value, and at each pulse T2 to decrement this counter. When it reaches 0, it generates a TTL signal, the counter is reinitialized to the good value and wait for T1seems easy but...

    DB:2.68:Start A Counter From A Trigger m1

    Just to say that, as Kevin said, the program, the method works fine. Now everythings seems to be OK. I'm not sure of the modification I've done on the signal but it works.Nevertheless, I've some problems with short delay... doesn't matter.perhaps the change of the type of trigger (rising-falling), I don't know...btw : I've added a "wait until 100ms" in the while loop it's easier to "manage the run" and it doesn't change the performance (as Kevin said).Thank'sChristophe

  • RELEVANCY SCORE 2.68

    DB:2.68:Ni-6132 Digital Output - Manchester Encoded Data Output md



    Hello

    I am using the NI-6132 capture card along with DAQmx and python in Ubuntu 10.10. Since my card has no analogue outputs, would be possible to program it to output either through the counter or digital ouput a manchester encoded square wave? I have written my encoder in python and I would like to output that code to an oscilloscope or any other device with a BNC connector.

    So far I have managed to capture a signal on the analogue input and create Pulse width modulation with the counter port. This confirms that my installation was successfull and interaction between the card and python is possible.

    Any input will be greatly appreciated, thanks.

    DB:2.68:Ni-6132 Digital Output - Manchester Encoded Data Output md


    Hi Peter

    Thank you very much for your response. I was hoping to get round this without using LabView as we don't have a license for it. As far as I know LabView does not support Ubuntu? Are you aware of any other way?

  • RELEVANCY SCORE 2.68

    DB:2.68:Co Pulse Ticks Problem mm



    Hi all,

    I have PCMCIA type 6036E card. I am trying to generate pulses in response to encoder signal. Pulse generation worked properly at the beginning, but it just stopped generating pulses randomly. Once it stopped, it never came back to operation. I had to rerun the program.

    My code is attached to this post.Encoder signal is received through PFI2 and pulse ticks are generated using counter 0. I used counter 1 to count the number of pulses generated.

    Have you guys come across similar problems before?

    Thanks.










    Attachments:






    Counter Pulse generation.vi ‏26 KB

    DB:2.68:Co Pulse Ticks Problem mm


    Hi hyperimage,

    How long does the program run before it stops working? I noticed that your top loop does not have any execution timing so your code is polling for errors as fast as the computer will run. Also, I would replace the DAQmx stop task with a DAQmx clear task and add a DAQmx wait until done VI before checking for errors.




    Cole R.National InstrumentsApplications Engineer

  • RELEVANCY SCORE 2.68

    DB:2.68:How To Send A Pulse Signal With Specific Frequency With Pxi-5412 7s



    Hi,

    This might be a silly question since I'm still new to Labview...

    I'm trying to control a PXI-5412 function generator to send a pulse signal (say 10 cycles, repetion time 10ms) to our ultrasound transducer. I need to assign a specific frequency to the sine wave I generate (like 1.055MHz). I assumed that I should use the arbitrary sequence waveform in the output mode, then generate a waveform combined with a sine wave and a period of DC, then make the loop count to 10, so I can get the pulse signal.

    I checked the examples in NI called "Basic Arb Sequence", which can do what I want, however, the way they design the signal is by # of points, not frequency... the vi called "Sine Wave [NI_AALBase.lvlib]" has two control terminals: # of points and frequency, I don't know how this work...

    So, my question is, can anyone help me figure out how to assign a specific frequency to the signal when I use the arbitrary sequence waveform to generate a pulse signal? or is there any other way can complete this task??

    Thanks!

    DB:2.68:How To Send A Pulse Signal With Specific Frequency With Pxi-5412 7s


    Wayne,

    Thanks for the reply. I thought I figured out how to solve the problem ... after I adjust the signal from the oscilliscope, it looks right.. thank you for helping this out, I appreciate it!

    cbing

  • RELEVANCY SCORE 2.68

    DB:2.68:Error 20315 z9


    Hi,

    Ineed to smooth an analogue input signal using both the 'Basic DC/RMS' and 'Filter' VIs. Data acquisition is triggered by an external device using a TTL pulse, butbetween TTLs (when no signal is being acquired) both the 'Basic DC/RMS' and 'Filter' VIs return the error 20315 - "The waveform dt parameter is = 0".

    Is it possible toovercome this and, if so, how?

    Many thanks in advance,

    P-Y.

    DB:2.68:Error 20315 z9

    Hi P-Y,Please can you post a code snippet to show the issue you are seeing, as the Basic RMS function should not operate without data, and the DAQmx Read should always send back valid data, or wait for data and prevent the RMS function from running.RegardsJamesCNIUK and IrelandIt only takes a second to rate an answer

  • RELEVANCY SCORE 2.68

    DB:2.68:Error 200140 And 200278 In Finite Retriggerable Encoder Triggered Sampling 38



    Hello,

    I have been using a rotary encoder to trigger a retriggerable sampling task. The encoder will give a pulse once per revolution and this will cause Labview to generate a finite pulse train which will be used to sample an analogue channel. The program will also return the pulse width of the encoder signal once per rev.

    A problem arises if the encoder is run at speed, I receive error 200140. But if I run the program at a lower speed I eventually receive error 200278.

    I am not sure why this is occuring as I am sampling continuously.

    Thanks,

    Ingram










    Attachments:







    Retriggerable_Finite_AI.vi ‏55 KB

    DB:2.68:Error 200140 And 200278 In Finite Retriggerable Encoder Triggered Sampling 38


    Hi Ingram,

    Thanks for your response regarding this issue.

    Just to clarify, you are using the PCI 6250 to measure pulses from an encoder which is generating one pulse per revolution and turning at 1000 rpm and you are sampling this at 50kHz.

    You are then taking these pulses and using them to trigger an input on the PCI 6220 which then reads the temperature. Does this mean you are taking 1000 temperature reading per minute?

    Without seeing how you are implementing this in your code it is very hard for me to tell if the crash is as a result of this. Just to confirm, are you still getting the same error message?

    Both the cards you are using don’t have simultaneous sampling; this means that the sampling speed is shared between your tasks.

    If you believe the issue is with your code then please do attach this to your next post.

    Many thanks,




    Aaron. EApplications Engineer Team LeadNational Instrumentsni.com/support