Irregular pulse train

In my DAQmx, I am using continuous acquisition while generating in DAC and ADC.
As a trigger signal, a counter signal sychronized with DAQ was used to control wave generator.
Can I make the irregular counter signal like attachment or use some concept like retriggering in generator?
I am asking about concept.
Labmaster.
Attachments:
pulse.png ‏4 KB

I can think of a couple of ways that you may be able to perform this type of operation.  First, you could use a digital pattern generation, and regenerate that pattern.  You would have to have a faster sample clock, so that each pulse would be more than one sample on the digital line.  (For example, perhaps your complete pattern could be 20 samples: 7 high, 3 low, 2 high, 8 low, and then that would repeat.) 
The other way to perform this would be using the buffered counter output functionality on X-series devices.  This allows you to pass a buffer of counter samples, with each sample consisting of a frequency and duty cycle.  If you use implicit timing, then it will output one cycle of each before moving to the next sample in the list. 
-Christina

Similar Messages

  • USB-6009 pulse train generation with digital output....

    Hello!
    I've bought a new USB NI-Card (USB-6009) and now I'm trying to adopt an old vi that uses traditional DAQ drivers. I wrote that vi for a PCI NI-Card (PCI-6024E), which has two counters to generate two pulse trains simultaneously. Now I've only one counter and that's why I'm searching for a good way to create pulse trains using a digital output! The pulse trains are both ranging between 100 Hz and 100 kHz.
    I'm sure somebody has an idea how I can solve the probem in the best way
    Kind regards,
    Peter

    You can't do it with this low cost board. Both digital and analog outputs are software timed only. The analog out is rated at only 150  samples/sec and the digital is about the same. You can't even use one of the counters because it is not a hardware timed counter output. It is an event counter only as an input.

  • Pulse train generation fails with certain values for "number of samples"

    I'm generating a retriggerable analog output signal, and so I'm using a counter as the sample clock (see: Retriggerable AI Using Retriggerable Counter). I am finding that, above a certain number of samples, and only for certain values of the number of samples, the counter task gives me error -200305, "Desired finite pulse train generation is not possibe." The error crops up only when actually starting the task.
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    Hmmm,  multiples of 50 & 100?  Now I'm puzzled again.
    Here's how to make sense of the 100 kHz timebase idea though, even if it turns out not to be the right explanation.  For a retriggerable finite pulse train, you actually use a pair of counters.  If you were to program it manually, you could set your output counter to generate a continuous pulsetrain at 800 kHz using the internal 20 MHz timebase.  This output counter would also be configured to use the other counter's output as a digital level-based pause trigger.  So the 800 kHz pulsetrain is only output while the other counter's output is, say, high.
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    So let's see...  An 800 kHz pulsetrain is possible with a 20 MHz timebase (exactly 25 cycles).  A 700 kHz (28 + 4/7 cycles) or 900 kHz (22 + 2/9 cycles) is not.  So when you request those other frequencies, you actually get a near approximation.  I dunno if DAQmx can be queried for the actual value correctly or not -- I recall an early version that reported back whatever freq you had asked for rather than what it actually used.  Queries based on ticks (rather than time or freq) did return what was actually used, as I recall.
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    Now suppose the request for 900 kHz turns into 22 cycles of the 20 MHz timebase, or a 1.1 usec period.  Now it takes 100 of those periods to get to 110 usec, which is also evenly divisible by the 100 kHz timebase.  Bingo again!  (Note: 110 is the lcm of 10 and 1.1).
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    -Kevin P.

  • How can I use the pulse train from a 6602 to trigger an niFGEN and niSCOPE on each rising edge of the pulse train?

    Hello,
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    Images of my current front panel and block diagram are attached. If you would rather have the actual VI's just let me know. Any help and/or explanation on this is greatly appreciated. Thanks in advance.
    Attachments:
    Front_Panel_Control.jpg ‏278 KB
    Block_Diagram_Control.jpg ‏263 KB

    Hello Cgifford,
    Welcome to National Instruments Forums.
    To output your signal to the PFI lines,
    you can use external connectios between OUT0 and PFI lines. You can also use
    the backplane to do so by routing into the same RTSI line.
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    On the SCOPE and FGEN, the name of the
    terminals are actually “PXI Trigger Line x/RTSIx” but on the 6602 you might
    need to route the signal using the property:
    You can also use the DAQmx route signal which perform the same opperation.
    2)
    This will depend on the frequency of
    your pulse train. If this is lower than about 10 ms, then you can probably
    place this on a loop and start and stop the acquisition every time. If the
    frequency is higher than this, you will have to use:
    -       Scripting on the FGEN side (read more)
    -       MultiRecord Fetch (more information in the scope help file
    section “Acquisition Functions Reading versus Fetching”).
    3)
    The short answer is yes. The longer one
    might depend on how tight you need the synchronization to be (us, ns, ps). For
    very tight synchronization, you should look into here.
    Message Edited by Yardov on 06-18-2007 03:14 PM
    Gerardo O.
    RF Systems Engineering
    National Instruments
    Attachments:
    property.JPG ‏7 KB

  • PCI 6602:How can I use the digital lines of the board and in the same time to generate pulse train using a counter?

    Hello!
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    Another thing what I manage to see using the  "Measurement & Automation Explorer" and Test panels for PCI-6602, basically is the same thing, I generate pulse train on the output of the counter 7 and try to start a task on the digital line, but I get one error :
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    Measurements: Resource requested by this task has already been reserved by a different task.
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    Ciprian
    Solved!
    Go to Solution.

    Hello Jordan, thank you for your reply.
    I am sorry but I can not see or run your example, I don't use LabView, I use Visual C++ for developing.
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        nStatus = DAQmxSetCOCtrTimebaseSrc(m_taskHandle,"Dev4/count5","20MHzTimeBase" );
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        return nStatus;
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    SetChannelState(short nState)
        short nStatus = 0;
        uInt8 wrtBuf0[1]={0};
        nStatus = DAQmxCreateTask("",&m_taskHandle);
        // Configure line as output 
        nStatus = DAQmxCreateDOChan (m_taskHandle, "Dev4/port0/line0", "", DAQmx_Val_ChanPerLine);
        nStatus = DAQmxStartTask(m_taskHandle);
        wrtBuf0[0] = nState;
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        nStatus = DAQmxStopTask(m_taskHandle);
        nStatus = DAQmxClearTask(m_taskHandle);
        m_taskHandle = 0;
        return nStatus;      

  • Can I generate pulse trains on more than one counter output at the same time?

    I have a PCI 6601 card with a BNC 2121 to connect the signals to two devices. The card is used as a trigger for both devices and I want to be able to generate pulse trains on two output channels at the same time, with a time delay between the two. How do I do that in Labview 7.1 Development with DAQmx?

    I feel foolish for not being able to figure this out, but it still doesn't work. Attached is the VI I use now. Counter 0 generates a finite pulse train and I programmed Counter 1 to generate a retriggerable single pulse triggered by CtrOinternaloutput. I still get the same error message: -50103 The specified resource is reserved. The operation could not be completed as specified.
    The same happens if I set the trigger for counter 1 at PFI36 (default output of counter 0) or any other PFI line. If I try a pulse train generation on only one of the counters, both work fine.
    If I try the example in traditional DAQ for multiple counter outputs with phase delay, it works fine.
    Can you tell me what I'm doing wrong?
    Attachments:
    Shutter_AND_lamp_trigger.vi ‏103 KB

  • How to continuously generate a pulse train with variable frequency

    Dear all,
    I am trying to use NI-USB 6259(BNC) to send Pulse signals to conduct position control of a servo motor with labview. The position control of servo motor follows these rules:
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    Time(s)
    Number of pulses
    Direction of rotation
    (1 is clockwise, 0 is counterclockwise)
    Frequency
    0-1
    923
    1
    923hz
    1-2
    3540
    0
    3540hz
    2-3
    1751
    1
    1751hz
    3-4
    2663
    0
    2663hz
    4-5
    353
    0
    353hz
    5-6
    1017
    1
    1017hz
    6-7
    3436
    1
    3436hz
    7-8
    302
    0
    302hz
    8-9
    1513
    1
    1513hz
    9-10
    570
    1
    570hz
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    I have already use the counter output of DAQmx, it just can generate pulse signal with certain numbers and certain frequency in one time. The attachment is the vi which can generate a finite digital pulse train from a counter output channel and the frequency, duty cycle, Initial delay, and Idle state are all configurable.
    How can I continuously generate  a series of pulse train with varying numbers and frequencies during a certain period of time.
    Thank you very much for your help!
    Solved!
    Go to Solution.
    Attachments:
    Counter - Finite Output.vi ‏57 KB
    Finite output.png ‏13 KB

    Hi aacuna,
    Thank you for your reply!
    I already checked that  article.  The frequency in that Vi can change dynamically, but the method of adjusting the frequency is ‘manual’ .Below is the front panel of that Vi. When the Vi is running we can change the frequency by press the button.   
    Time(s)
    Frequency
    0-1
    923hz
    1-2
    3540hz
    2-3
    1751hz
    3-4
    2663hz
    4-5
    353hz
    5-6
    1017hz
    6-7
    3436hz
    7-8
    302hz
    8-9
    1513hz
    9-10
    570hz
    Thank you！

  • How do I send a 2-10 MHz pulse train to my DAQ 6052E why simultaneously reading in data? I'm using the NIDAQ Tools with Igor Pro.

    I need to send a continuous 2-10MHz TTL timing signal to a low pass filter (to set the cutoff frequency) while I collect data from one of the analog inputs. I'm hoping that I can send the TTL signal and collect the data through the same DAQ 6052E board.
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    Thanks for your help

    You can program one of the counters to generate a continuous pulse train. Once programmed to do so the counter needs no further interaction. It will continue to generate the signal until stopped through SW. So you can start the counter using the functions provided to you, then forget about it and program the AI operations.
    Christian Loew, CLA
    Principal Systems Engineer, National Instruments
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  • How to change the frequency of pulse train on the fly using an array of values?

    Hi all!
    First I want to thank U for the great job you are doing for this forum.
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    Regards
    Chris
    Attachments:
    number_of_steps.txt ‏17 KB
    frequency.txt ‏15 KB

    Tiano,
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    Justin Britten

  • HOW TO GENERATE FINITE AND CONTINUOUS PULSE TRAIN WITH USB6216 AT THE SAME TIME?

    Hello.
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    Hello.
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  • Need to unreserve a counter in a finite pulse train generation

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    Hello,
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  • How to change the frequency of a finite/continuous pulse train in the program?

    Hello!...
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    My aim is to get the pulse train to clock a stepper motor controller, in such way that the speed of the motor increases when the data of the spreadsheet increases and vice-versa.
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    ere I have gone wrong and/or give any suggestions?
    I have attached my vi and the spreadsheet file.
    Thanks
    Tiano
    Attachments:
    My_VI.vi ‏99 KB
    wave.txt ‏18 KB

    Tiano,
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    You are using the Tab Control in a way I have never seen before (I don't think it will work this way either. Tab Control is for presenting and hiding controls, indicators, labels, etc. on the front panel, before running the VI. They are not used to control the program functionality itself. Typically you would use a Boolean to choose between 2 options for a Case Structure.
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    Mike

  • DAQmx - Measuring only the pulses w/o pauses of a pulse train

    Hi everyone,
    I've got a problem which I hope you can help me with.
    I'm using a NI 4461 PXI DAQ-card on a PXI realtime system and LabView 8.5.
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    But unfortunately it's not working at all.
    Could you tell me, how to configure a task to do that job, please?
    Thanx in advance,
    Ralf

    Hi Ralf,
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    Feel free to post any other questions here regarding this topic.
    Regards
    TomBaum

  • Generating a pulse train

    Hello everyone,
    I'm using one counter timer from the DAQ card PCI-6014. I want to generate a pulse train with this output where I can control the number of pulses and the frequency of the pulse. The duty cycle is not important, I want to use the default value, i.e. 50%.
    I have used the vi called "train_impulsion2.vi" with the following values:
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    -duty cycle = 0.5
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    Marc  
    Attachments:
    train_impulsion2.vi ‏21 KB
    daq_assitant_pulse_train.vi ‏101 KB

    Hello everyone,
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  • Using a SCC counter pulse train to control a SCC digital out signal

    I am trying to send a digital high signal on a SCC-Digital ouput module for a certain number of pulses generated by a SCC-Counter/timer pulse train. I have found examples of how to route such signals through PFI12 etc on an M-series board but I am trying to achieve this without referring to the card, just the SCC modules themselves.
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    Is there any way I can do this without referring to the connected M-series DAQ card channels?
    Thanks in advance for your assistance.
    Cheers.

    Hi Phil,
    The SCC carrier is only conditioning your signals (i.e. if your signals are not in optimal ranges, bandwidth or need external excitation). The actual counters and all digital lines are controlled directly by the M-series board. This means you will never be able to refer to a counter in the SCC module.
    If you route the signals of the M-Series board, is as if you had done so externally from the SCC. Look at this example and might give you more insight to how to implement it (This is software timing). The hardware timing would be doing correlation DIO. Here is an example that needs to be modified to adapt to your timing: http://zone.ni.com/devzone/cda/epd/p/id/4414
    Hope this helps,
    Yardov
    Gerardo O.
    RF Systems Engineering
    National Instruments
    Attachments:
    Finite Dig Output High.vi ‏31 KB

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