Output trigger pulse width

The data sheet on most (all?) the switch modules (I'm working with the 2530B, but that's really not relevant) mention that the output trigger pulse width is settable between 1uS and 62uS programmatically. 
http://sine.ni.com/ds/app/doc/p/id/ds-330/lang/en
(about 1/2way down page).
However, I cannot find any reference to any property that you can set to modify this parameter.  By default it's coming out at 2uS wide.  I'm trying to capture the pulse using a microprocessor, but the pulse width is narrow enough that it's not getting it.  There is no configuration for this in MAX.
I can't be the first person to try this.  Anyone have any idea?

Hi Fast351,
You can program the pulse width using a DAQmx Export Signal Property Node in LabVIEW. From the property selection you would go to Events»Advance Complete Event»Pulse»Width Value. In C, you would use the DAQmxSetExportedAdvCmpltEventPulseWidth function.
-Jake B.

Similar Messages

  • How do I program a NI 6602 card to send trigger pulses, one at each output port, triggered by an input trigger signal, using only one counter for each output port?

    Hello,
    I have managed to program a NI 6602 card in LabView to send pulses on three different output ports, one pulse on each output port (with individually chosen delays) for each input trigger pulse coming on a separate input port. It is the DAQmx Create Channel (CO-Pulse Generation-Time)-VI that I have used for this, see attached code. However, this VI controls both pulse delay and pulse width, and therefore uses two counters for each output port (although you only specify one counter in the VI input signals), as I understand.
    In my application though, I only need to have the delay chosen, the pulse width can be arbitrarily short, and thus I should only need one counter for each output port. How do I accomplish to program this in LabView?
    Best regards,
    Claes
    Attachments:
    Configure Side Camera Flash 1 Triggering.vi ‏47 KB

    Well you're welcome to do that--it will work just fine as long as you are configuring a start trigger.
    <rant>
    However, personally I really don't like putting multiple counter outputs in the same task.  I have seen so many people assume that the counter outputs would be synchronized due to having them in the same task when this is not the case (you need to configure a start trigger in order to synchronize the counter outputs even if they are in the same task).  This is the only case I can think of where multiple channels in a DAQmx task are not automatically synchronized.
    As an example:
    Running this on my PCIe X Series gives a measured 2 edge separation of 1 ms + {7.78 us - 10.11 us}.  This would likely be much worse on a bus with more latency (e.g. USB).
    The resulting output is close enough to what you might expect that it might go unnoticed, but really these counter outputs are not synchronized and it would be easy to glance at the code and not even think twice about it.  For the small amount of extra work on my end to create a separate task for each counter, it really clears up some ambiguity about what the counters are actually doing.  For me it's worth it.
    So again, for your case there really isn't a problem with having the counters in the same task since you are using an external start trigger anyway.  I have just gotten in the habit of avoiding doing this.
    </rant>
    Best Regards,
    John Passiak

  • How can I configure the CTR 1 GATE to output a pulse (10us long) and then immediatel​y take a pulse width measuremen​t?

    I'm using the BNC-2120 DAQ and LabVIEW for interfacing with an ultrasonic position sensor.  The sensor is the "PING))) ultrasonic range finder."  It measures the distance from PING))) to some object directly in front of it.  It has 3 pins (5V, ground, and a signal pin).  The 5V and ground are easily taken care of with the 5V and digital ground outputs on the DAQ.  The signal (SIG) pin works in the following way:
    1) Send a 10us, 5V pulse to SIG.  This triggers PING))).
    2) Wait 200us.  PING))) takes a distance measurement.
    3) SIG outputs a square wave with a specific pulse width. 
    The pulse width varies with the distance of the object away from PING))).  I've tried using CTR 1 OUT to generate the pulse, and then using CTR 1 GATE to measure the pulse width.  However, the measurement is stuck measuring 0V because CTR 1 OUT is on the same pin!  So PING))) tries to output a pulse, but cannot due to the fact that CTR 1 OUT forces the SIG voltage to be 0V.  So I need to use just one counter I/O line to trigger and measure.  How can I do this?

    Hi Matttastica, 
    What DAQ
    card are you using? The reason I ask is that the PFI lines on some cards can be
    used as PFI lines and digital I/O lines, while on others they can only be used
    as PFI lines. The pinouts and diagrams for our cards can be found at www.ni.com/manuals. You can accomplish
    what you are looking to do if your PFI line is a DIO lines as well.
    I would
    suggest doing two tasks, one for counter output and one for counter input.
    (Note that both these are not going to be the same line). The counter output
    will be used to do a single pulse generation, while the counter input will be
    used to read back the period. 
    This will
    work because, at first, we are going to route the line from the counter output
    to the counter input line by using a ‘DAQmx connect terminals’ (basically
    making the input line an output line for a moment). First, setup the tasks and
    the DAQmx connect, start the tasks and have the counter output do a ‘wait until
    done’ to ensure the pulse is sent. After this is done, do a DAQmx disconnect
    terminals (turning the input back from an output to an input), and then do a
    DAQmx read for your counter input (period measurement). You may look at the
    shipping examples for pulse generation and period measurement in LabVIEW (Help »
    Find Examples... » Search tab … search for examples)
    One note is
    that since this is software timed, it may not be fast enough to meet your 200us
    timing. If this ends up being the case, please look at the 6552, as it can do
    per clock cycle direction change very fast.
    David L.
    Systems Engineering
    National Instruments

  • How to generate and output 3 TTL square waveforms with different pulse widths using counters of NI 6034E

    Hello
    I just have a few questions.
     I am using the NI 6034E DAQ board in order to
    generate simultaneouly 3 different TTL digital signals, with different
    pulse width, and output these TTL signals to an external circuit that I
    am using for this application.
    The following pattern of the TTL pulses will look like this:
    01010101 01010101
    00110011 00110011
    00001111 00001111
    From
    what I understand,  I have to use the 2 counters, Ctr0 and Ctr1, to
    generate the TTL pulses that I desire, because the DIO lines are
    software timed only and I will not be able to produce a deterministic
    output period using these DIO lines.  Am I correct?    Also, do I have
    to use a separate counter to generate a separate TTL digital pulse.  I
    need 3 different TTL pulses and there are only 2 counters for this DAQ
    device.  The three generated TTL signals will be feed to an external
    circuit.  Concerning the hardware connections for my application, I
    assume that the generated TTL signals will be output from
    GPCTR0_OUT(pin 2)  for counter 0 and GPCTR1_OUT(pin 40) for counter 1
    of the NI 6034E. Is this correct?  Is there any way that these TTL
    signals can be output from three DIO lines(DIO0...2). 
    Here is some code that I plan to use in order to do this:
     #include <NIDAQmx.h>
    static TaskHandle gTaskHandle = 0;
    DAQmxCreateTask ("", &gTaskHandle);
    DAQmxCreateCOPulseChanTime (gTaskHandle, "Dev1/ctr0", "", DAQmx_Val_Seconds, DAQmx_Val_Low, 1.0, 2.0, 2.0);
    DAQmxCreateCOPulseChanTime (gTaskHandle, "Dev1/ctr1", "", DAQmx_Val_Seconds, DAQmx_Val_Low, 3.0, 4.0, 4.0);
    DAQmxCreateCOPulseChanTime (gTaskHandle, "?????", "", DAQmx_Val_Seconds, DAQmx_Val_Low, 7.0, 8.0, 8.0);
    DAQmxCfgImplicitTiming (gTaskHandle, DAQmx_Val_FiniteSamps, 5);
    DAQmxStartTask (gTaskHandle);
    DAQmxWaitUntilTaskDone(gTaskHandle)
    DAQmxErrChk DAQmxStopTask(gTaskHandle)
    DAQmxErrChk DAQmxClearTask(gTaskHandle)
    I believe this code should generate the 3 TTL square waveforms that I want for my application.
    Please provide me with some feedback.  It would greatly be appreciated.
    Thank You

     Hi,
    The NI 6034E is a multifuntion DAQ device, this means you have:
      (2) counters
      (8) DIO lines (software timed)
      (16) AI, single ended
      (0) Analog Output
     You have a couple choices here:
       1. Software timed digital output of all three signals, max 1khz loop rate, non-deterministic.
       2. Hardware timed digital output of 2 signals, max 20Mhz.
       3. Hardware timed digital output of 2 signals and software timed digital output of 1 signal.
       4. Find another NI MIO board such as the NI 6251. This board will do 10Mhz pattern generation for (8) DIO lines.
    For the hardware connection, you are correct, the output for the counters will be taken from pin 2 & pin 40.  Here's the pinout for the NI 6034E for reference:
    The output of the Counters can be routed to some of the PFI's or to the RTSI connector. You can see this in MAX
    Message Edited by Matthew W on 11-19-2007 01:24 PM
    Attachments:
    2007-11-19_131609.jpg ‏61 KB
    2007-11-19_132435.jpg ‏86 KB

  • DAQMx has no output when the pulse width is less than 0.1sec

    Hi,
        I am developing a application to generate square wave(voltage) and out put from a DAQMx card (PCI-6723   - 32 point analog in/out).  I attache a simplified code (labview8.5) I wish somebody can help me to figure out what is the problem
        When I set pulse width longer than 0.1 sec. everything works fine. If I set the pulse width less than 0.1 sec, the output from DAQ eithet gets nothing or incorrect(I used a Osclliscope to monitor the  DAQ output), although my labview monitor showed correct output.   I wonder if it is a sampling issue of the DAQ card.
         Thanks
        Guang
    Attachments:
    test21.vi ‏69 KB

    I think one or two things could be causing the problem.
    1.  Your DAQmx write is set for 1 sample.  I don't know how that dynamic signal type works with such a setting.  Perhaps it is just putting out the first sample of the signal that is generated.
    2.  The math for the frequency of the square wave does not make sense.  You are adding a pulse delay with the pulse period, then inverting it to get the frequency.  So a 1 second delay with 1 second pulse is a 1/2 Hz wave.  A 4 second delay with a 2 second pulse would be a 1/6 Hz wave.  That doesn't make sense to me.
    I would recommend building your own waveform or array and not using the express VI.  If you have a 1000 Hz frequency established let's say, build a 1000 element array.  For a .1 second pulse, set replace 100 of those elements with a 100 element array of the voltage value you want.  You can index it wherever you want in the array to account for whatever delay you want.  If you want a 1 msec pulse, then just replace a single element of that array wherever you want.

  • What is the minimum pulse width output for PCI7831R?

    I have a problem to generate the signal output by using PCI7831R.
    I have used Labview FPGA program and PCI7831R with my experiment.
    When I tried to output a signal which has a pulse width less than 2msec, Its pulth width becomes double or triple longer than I set.
        For example, if I set the pulse width 1msec, its output pulse width became 3msec...
                              But if I set the pulse width 2.5msec, its output pulse width is just 2.5msec.
    Internal clock is 40MHz and theoretical rate is 53.5MHz. And the cycle time of main loop is less than 0.5msec.
    (I believe those value are fine to generate the 1msec pulth width output.)
    My questions are
    -What is the minimum pulse width for PCI7831R?
    -Do you have any idea to solve this problem?
    I attached the picutre of my VI.
    (because this picture is a little old, It has broken wires. But it is fine now.)
    If conditions are all good, this VI will output the signal during "Injection Duration(micros)" micro-second.
    Thanks,

    I'm sorry I could figure out what was the problem.
    And I also find the minimum output pulse width on the catalog (12.5nsec).
    Thanks,
    Kaoru

  • How to generate a pulse train with different pulse width and delay?

    How to generate a triggered pulse train with different pulse width. for example, after each trigger signal, let's say 2 ms, then the counter output a pulse with pulsewidth of 1 ms, and then after 3 ms delay after the first pulse, the second pulse was generated with a pulse width of 4 ms.  Next cycle when the trigger signal comes, the same two pulses will be generated and so on. Is it possible to achieve this by using 6601 counter card? and if yes, how to achieve this? Thanks!

    Unfortunately you can not create a hardware timed pulse train with different widths on each pulse from a counter. Whilst it can be changed on the fly using software, since you require a hardware triggered signal getting the software involved will not give a huge amount of accuracy when the pulse will actually change.
    So in short you can't use your 6601 card (or a counter timer) to achieve this
    There are three possible Alternative solutions
    1 You could use a high speed digital IO device such as the (6533/34) to generate your variable signal which would require setting up the pulse train as a series of states based around the burst transmission mode where the clock would give you your specific timing.
    2 A timed analogy output (for example on a MIO card with a clock (PCI-6220 / 62xx), i.e. Not the 6704 style static analogy output cards)
    3 A high speed digital waveform card such as the (, 656x , 655x, 654x, 6534, 6533 (http://www.ni.com/modularinstruments/find_right.ht​m) ) this could then be scripted to work with your triggering and also there is a digital waveform editor which will enable you to set up the pattern you wish to generate (http://sine.ni.com/nips/cds/view/p/lang/en/nid/135​55) 
    Hope that helps
    Tim Matthews
    NI (UK)

  • Minimum pulse width needed for gating the counter

    Hi,
         I have TTL pulses of 20 nanosecond width coming out from the two detectors at random times. I want to count the number of coincidence pulses.I am trying this with NI PCI 6259 M series card, by giving one signal to the gate of the counter and other as a source of the counter (Single Point (On-Demand) Edge Counting with Pause Trigger). When both source and gate are high then it should give the coincidence count.Can anyone suggest  
    1) Whether this is possible to gate the counter with 20 nanosecond width pulse?
    2) If above thing is possible is this the right way for looking coincidence counts?
    Any help regarding this is highly appreciated. 
                                                                                                                                                                                                                                             Regards
                                                                                                                                                                                                                                              surya
    Research student

    I'm sorry I could figure out what was the problem.
    And I also find the minimum output pulse width on the catalog (12.5nsec).
    Thanks,
    Kaoru

  • Triggered single pulse width measurement

    I am trying to measure the width of a single pulse, but would like to use the pulse itself as the trigger for a counter input pulse width read using a PXI-6608.  I would like to do this since the pulse can come at any time (much longer than any practical timeout)  and I would like to avoid having to place a DAQmx read in a while loop waiting for the pulse to appear.  Also, while the pulse is high, I would like to produce front panel feedback (light a boolean indicator).  I seem to be able to achieve that by using a digital input line, but again requires a DAQmx read in a while loop.  I haven't had much experience with triggers and my attempts so far appear to seem like triggers are not compatible with counter input pulse width measurement.  Is it possible to set up a trigger for a pulse width measurement?

    Hello kayotik,
    I think the best thing to do here is to use separate while loops. You can put most of your code in a main while loop, and then put your DAQmx read in a separate while loop. Both loops can run in parallel (just don't wire any outputs of one while loop to the other while loop, because then one will become dependant on the other). In order to pass data between the two loops, you will need to use a local variable. The DAQmx read can write to a local variable, and the main loop can read from that local variable. 
    You will also need to stop both loops with a single stop button. This article shows how (and also demonstrates the use of local variables to pass data between independent while loops):
    http://digital.ni.com/public.nsf/allkb/267704CDE91156D186256F6D00711AAE
    Colden

  • Single Pulse Width with External Clock

    I am trying to setup a 6602 counter for a single (non-buffered) pulse width measurement with an external clock. Under normal testing, the unit under test will provide the pulses, I need to measure the number of pulses during different time periods (1, 60, and 300 seconds). I want to do a pulse width measurement and I'll supply the gate signal pulse to the counter for the specific time needed.
    Under normal operation, the unit under test is wired into the counter's source and the pulse is wired into the gate.  For testing purposes I am using a BNC-2121. I have the counter's source wired to the Adjustable Square Wave Output and the gate wired to the Trigger output.
    Here is my C++ code. I am getting a timeout error on the read and I don't know why. Any help would be appreciated.
       //Create Task
       DAQmxCreateTask( "task1", taskHandle );
       //Create Pulse Width Channel
       DAQmxCreateCIPulseWidthChan( taskHandle,              // TaskHandle
                                                      ​  szCtrName.c_str(),     // Counter Name
                                                      ​  "",                             // Channel Name
                                                      dMin,                          // Min Value
                                                      dMax,                         // Max Value
                                                      DAQmx_Val_Ticks,     // Units
                                                      DAQmx_Val_Rising,    // Gate Edge
                                                      "" );                            // Scale Name
       //Set the Pulse Width Terminal to the gate signal
       DAQmxSetCIPulseWidthTerm( taskHandle,          // TaskHandle
                                                     "",                       // Channel
                                                     "/CTR2/PFI38" );  // Terminal
       //Set the Timebase Src to the counter's source
       DAQmxSetCICtrTimebaseSrc( taskHandle,         // TaskHandle
                                                    "",                       // Channel
                                                    "/CTR2/PFI39" );   // Terminal
       //Start Task
       DAQmxStartTask( taskHandle );
      //***Send pulse to gate counter***
       //Read Counter
       DAQmxReadCounterU32( taskHandle,                      // Task Handle
                                              DAQmx_Val_Auto,           // Num Samps to Read
                                              10,                                  // Timeout
                                              ulBuffer,                           // Read Buffer
                                              1000,                               // Buffer Size
                                              &lSampsRead,                 // Num Samps Read
                                              NULL );                            // Reserved

    I've setup a pulse width task in NI-MAX using the onboard clock and everything worked fine, so I know the hardware is working.
    My unit under test is providing the pulses (from gyros) I need to measure. The pulses indicate the position of the unit so there are X, Y and Z axis gyros. I need to measure these pulses for specific periods of time (1, 60, and 300 seconds). For example during the 1 second measurement, the X and Y gyros should measure zero pulses and the Z axis should measure 515 gyros. During a 300 second measurement the X and Y gyros should measure < 60 and the Z axis should measure 30800.
    So the gyro pulses are wired to the counter input and I am using a DIO channel from NI-6508 to provide the gate pulse. The gate signal will be high for either 1, 60, or 300 seconds depending on the test. The gyro pulses are essentially the external clock to the counter. I want to count the gyro pulses during the pulse of the gate (DIO).
    To simplify the setup, I connected to BNC-2121 directly to the card. I have the adjustable clock output going to the counter input of ctr0 and the trigger signal going to the gate of ctr0. Once the task has been started and before the read ( I had a breakpoint set in the code), I would press the trigger button on the BNC-2121 and hold for approx. 1 second. I then execute the Read statement, and I always get a timeout. From my experience working with NI, I'm guessing I don't have a channel property set correctly, but its not obvious to me and I can't find an example to do exactly what I'm trying to do.
    The CTR2 designation in the code was the object name of the card. I have two 6602 cards in my chassis. I was using ctr0 of the second counter card, so PFI38/39 was correct.
    Again, any help would be appreciated.

  • Measure pulse width of signals generated by DAQ

    Eventually, I would like to:
        Start a counter pulse width measurement and analog out at the same instant.
        Stop the pulse width measurement with an external digital signal.
    My current plan is to use a digital out on the DAQ to go to a digital input and the counter start input.  The digital input will be a start trigger for the analog output.  This works, except for the counter.
    While trying to implement this, I tried a simpler test of just generating a digital pulse with the DAQ and wiring that to the counter inputs.  That doesn't work, even though it looks fine on an oscilloscope.  Then, without changing the software at all, I connect a function generator to my  counter inputs, and it measures pulse widths flawlessly.
    I'm actually implementing this with a Python wrapper around the DAQmx C API, but I recreated it in LabVIEW, and it behaves the same.  VI attached.  I have the latest DAQmx drivers.
    Attachments:
    meas_pulse_width_simple.vi ‏32 KB
    screenshot.png ‏99 KB

    ColeTrain wrote:
    apaulsen,
    Just a
    friendly heads up, but this is more of a DAQ post and you will
    generally get more replies to these types of questions by posting in
    the proper forum.
    That being said, try taking a look at
    the Example Finder and look under the DAQmx examples at
    synchronization/multifunction as this would be a good place to start
    working on what you're trying to wind up doing down the road. 
    I am actually the OP.  apaulson is my coworker, and he was logged in to the forums on the workstation from which I posted.
    I
    realized that it ended up in the LabVIEW forum, so I reposted on the
    DAQ forum:
    http://forums.ni.com/ni/board/message?board.id=40&thread.id=7185. 
    I understand why there is a search-to-post policy, but it's rather
    unintuitive and clunky, and I got confused.  IMHO, ubuntuforums.com
    does this the right way and automatically searches before you submit
    your post.
     Anyway, I figured it out.  See the other post for solution.

  • Pulse width modulated signals

    Is it possible to generate a fixed frequency with variable duty cycle signals using counter/timer channels of my DAQ 700?
    If yes, is there any example I could download?
    If no, I am looking for a DAQ card that can handle
    the job, I'd appreciate any recommendation.
    Another part of my project is to read in a analog signal while generating this pulse width modulated
    signal. So far I am not very lucky with one DAQ,
    I am thinking of getting two. Does it sound overkill?
    Please help.
    Thanks

    Could you provide a timing diagram for your digital signal?
    I am a firm believer that a digital output device such as an NI timer can create any signal, given the proper software or hardware. I once did a high speed, gated, triggered data acquisition with only a single NI timer chip on the AT MIO 16E-1. It required about 75 feet of BNC cable, more PFI wires than you can imagine, four external logic devices (AND and OR, NAND and NOR boxes) all interconnected and basically tangled. I don't think I could repeat that setup without my documentation, but the point is, it worked.
    The most important thing from that example is that I used a timing diagram. These are so vital in digital IO and timer applications that its not funny.
    If you can't determine ho
    w to do what you need from a timing diagram, just send me a copy, let me know what the basic specs are of the DAQ 700 (how many counters, interconnect capabilities, etc) and I can try to help.
    Good luck.
    As far as reading the analog signal at the same time...well, look at my example. I generated the trigger/gate signal with the card, and then read in the analog data (on several channels simultaneously.)

  • Measure pulse width and generate pulse depends on the width

    Hi,
    i have a serias of pulses ... 600 micro,30 micro,30 micro (around 10 times) ........ nothing for 1 mili second ..
    so i need to generate a pulse after the first pulse arrives ... (its width around 600microSecond)
    1. use the first counter to measure the pulses ...
    2. if arrived pulse ... 500microSecond<the pulse width<700microSeconds .... then generate pulse with second timer ....
    the problem is that i dont want to use the while loop inside the labview ...
    can i programm the counters to make the width calculation and if the width is bigger to generate trigger to the second counter .... ?
    the hardware is 6014 sample card ....
    thanks
    gena
    (see attached)
    Attachments:
    F0087TEK.JPG ‏27 KB

    Hi Gena,
    I am assuming you are using the DAQmx drivers in LabVIEW for your
    PCI-6014.  Avoiding a While loop may be difficult if you need to
    perform this measurement many times and you might not know when the
    signal is going to begin.  Without a While loop, you'll have to
    set up your timeout period long enough so the pulses will begin before
    your VI stops.
    With this in mind, you may want to look at some of the shipping
    examples with the DAQmx driver.  You can find these in LabVIEW's
    Help menu by going to Find Examples.  For measuring the pulse
    width, browse the folders in the Example finder by going to Hardware
    Input and Output>>DAQmx>>Counter Measurements>>Period
    or Pulse Width.  In this folder, there is the Meas Pulse Width.vi,
    which measures the pulse width once and stops.  You should be able
    to take the pulse width measurement you get from here and check to see
    if it's in your range, then output a pulse on the other counter if it
    is in the range.  The pulse output examples can be found in
    Hardware Input and Output>>DAQmx>>Generating Digital
    Pulses>>Gen Dig Pulse.vi.
    Thaison V
    Applications Engineer
    National Instruments

  • In Delayed Pulse Generation vi,Problem With THE PULSE WIDTH??

    In Delayed Pulse Generation vi, I want to input a very low number for the Pulse Width while using an external timebase source. But the minimum pulse width has to be 2. Does anyone know how can I solve this problem??

    Hey 45,
    Unfortunately, there is no way to generate a pulse width smaller than 2x your external timebase.
    There is an option to create a pulse of arbitrary width of your external source if you can afford some software processing in between. What you can do is use 1 counter to measure how many source edges of your card's internal timebase (80 MHz for TIO only, 20MHz or 100kHz for TIO and STC) your external signal is. This uses pulse width measurement as the counter application. Once you know how many source edges it takes to represent your pulse, then you can use triggered pulse generation and use the internal timebase with the pulse specs set to create the exact pulse width you want (and delay) and you can use your external pulse as the trigger. Th
    is works well if your pulse is always the same width and you can measure it before hand. As an example, let's say your pulse is 20 internal timebase pulses when measured. This means you can use the pulse specs to specify a pulse width of 0.75 your pulse width by using only 15 internal timebase edges for your pulse width.
    I don't know if I was clear above or not but if you give me your exact application you are looking to achieve, I might be able to help you out. Hope that helps.
    Ron

  • Changing the pulse width of a counter on-the-fly - ?

    I'm seeing strange behavior when trying to change the pulse width of a
    counter while it is running continuously.  Using the property node
    I can set the DAQmx Channel Properties "Low
    Time" and "High Time" when the values are
    changed by the user (see attached VI).  The first change is
    ignored initially, but then applied when a second change is made, i.e.
    the changes are applied one step late.  If I read the respective
    properties the values are what is set but not what is being
    generated and seen on an o-scope.  I added a
    condition of watching the property "Ready For New Value" before applying the
    change, but that doesn't alter the behavior.  What am I missing?
    Windows XP
    LabVIEW 7.1
    DAQmx 7.4.0f0
    PCI-6251
    Thanks,
    DTL
    Attachments:
    GenDigPulseTrain-ChangingSpecs II.vi ‏104 KB

    Alan,
    Thanks for the reply.  I don't know if I explained in well in my
    previous post, but I'll try to confuse again: The issue is that the
    property node change is reflected on the hardware (pulse output) one
    change delayed.  Example: Start the VI with time value A. 
    The user sets the time to value B, the property node read for the time
    will read value B, but the output pulse (hardware) stays at value
    A.  Then the user sets the time to value C, the property node read
    is C, but the output is now B, and so on...
    I've worked with the DAQmx Write, as the example you pointed to shows,
    and it will work properly (reflect the change immediately on the
    hardware).  If one replaces the DAQmx Write to a Channel Property
    Node it will start working as I described above (change reflected one
    change delayed).  Note: A subtle additional change is that I have
    changed everything to Time (High, Low) instead of Frequency (Duty
    Cycle,  Frequency) - ?.  Note 2: DAQmx Write doesn't bring
    out all the properties - what if I have to use a property node? 
    Do I need to "double pump" the values?
    FWIW,
    Don

Maybe you are looking for

  • COGS workflow-Using Different Cost of Goods Sold Account

    hi all, Could some one interpret this and tell me exactly what it is. This is the customization of cogs workflow. Ive to use different COGS account when the fares are sold on promotion.and COGS account should be different between regular fares and pr

  • Need to reload Safari pages to be able to click on a link

    Many often I need to do that. ?

  • Generic Connectivity for 64-bit 10gR2 on Windows

    I want to create a database link from a Windows oracle database to SQL Server 2005. The obvious solution seemed to be generic connectivity using HSODBC. However, I don't have HDODBC.EXE in my 64-bit oracle home. Doing some investigation, it seems tha

  • Document security

    Hi I need to transfer documents (.doc,.rtf and ,pdf)What shall i use to encrypt the documents when those transfering Thanks

  • Links List description column

    How to get the description value of the hyperlink field in the link list for xslt list view webpart ? i.e how do I get the value of description in the XSLT that I provide for XslLink?