Change axis step pulse width - NI 7340

Hi,
I'm controlling a stepper motors with a NI-7340 and UMI 7774 without feedback. With MAX I've configured the interface and I can see the step & dir waveform on the scope.
But, the step pulse is only 20us wide and my motor driver does not see it.
How to increase the pulse width? I have tried using Set u32.flx in LabVIEW, but the pulse width has not changed. I have attached the VI and MAX configuration (zip file).
Please help me.
Thanks.
Attachments:
Straight Line Move.vi ‏80 KB
configData.nce.zip ‏838 KB

duplicate post

Similar Messages

Change pulse width in a continuous generation using an array of High/Low Times using NI-DAQmx

Hi,
I'm using a PCI 6259 (M-Series) Multifunction DAQ, and I want to use a counter to output a pulse train with changing low times. I want to use this output signal as an update clock, where values of Digital Output Channel, and the Analog Output channels updates to new values sequentially in the order specified in their repective 1D arrays in the front panel. I want the updates to happen at every rising edge of the clock pulse. The times when I want this update to happen are also user-specified by an 1D array of times in the front panel. So I'm trying to configure one couter to output this changing width pulse train.
I'm new to Labview/Ni DAQ. I'm using NI DAQmx, so far its been really nice and readable, and easy to understand. Even though I have never used NI-DAQ, I can clearly see that NI DAQmx is certainly much more programming friendly than NI-DAQ. I looked at the VI's available in the example, and also through many simlar posts in these Forums, and some web documents for my problem. Most of the solutions have focussed on changing times on the fly while the application is running. I want to specify the different times before a "DAQmx Start Task" is called. I'm wondering wether this is possible.
I was hoping I could store the pulse width values in a buffer, and the counter could keep outputing pulses with different widths in one continuous operation. The M-Series help file says that it is possible to do that "seamlessly", but I dont see yet how I can use the NI DAQmx to do that. Attatched is the part of the Help file where it says that.
Any help will be greatly appreciated.
Attachments:
Counter_Change_Frequency_Help.pdf ‏21 KB

Hi Kevin,
Thanks for your message. Well, I would like to point you to the 'DAQmx Timing' vi, which has an instance for change detection applications with digital input. I'm new to LAbview, but I'm wondering wether you can use that for your applications. Yes, I have seen the Viewpoint boards and their programs.. I have actually also looked into their Vi you are talking about, Kevin, for ideas to use with my board, but the core of the program is in C, which is something I would use as a last option, specially since I bought Labview to make life easier.
To get back to the subject of my post, their is a vi 'DAQmx Write", and one of its instance is 'Write Counter Single Channe SINGLE Sample', and there is no 'Multiple Sample" option available for writing counters, as is for the Digital Ports and Analog Outs. That seems to be a bit surprising. To refer the following example
http://zone.ni.com/devzone/conceptd.nsf/webmain/90DFE241E571056C86256FA4004ABB63
(pulse width modulation with NI-DAQmx)
If one can change values of pulse widths on the fly, I would assume thats it should also be possible to pre-define a sequence of pulse width values in a buffer from which the counter 'banks' can access the next pulse width from. ('Banks' are the 2 load register pairs for the counters and is described in the part of the M-series help file attatched in my earlier post).
Hopefully somebody from NI can address our problem. And yes Kevin, currently I have 2 options,... 1. to create a digital waveform before hand, which will use a large buffer ( I want an experiment to run for 1s, with 0.1us timebase, or
2. To use the example in the above web document and modify it a bit. Here frequency is changed on the fly, and a while loop checks if the frequency is changed in the at regular intervals. I could instead use a for loop to keep changing the frequency values, but I tend to think that the speed will be limited by software. I'm not sure .. I haven't tries that out yet.
Hopefully someone can send me a nice elegant solution.
Thanks.
Shomu

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

Can I change the delay or pulse width on a trigered pulse on the fly in DAQmx

In the old DAQ driver you could not change the a triggered pulse delay or pulse width on the fly of a as there was a problem in the DAQ driver or was this a hardware problem?
Is this now possible with DAQmx , if not why not as you could do this with the old 16 bit cards in dos by updating the registers.
This has been a major problem with NI counters timers and one would have thought that by now this problem would be fixed.We need to do this with out stopping and restarting a task.
Any help here.
Ta
Colin

Hi Colin,
Please can you try the suggestion in this KB. hopefully it should still work with what you are doing. I can not find any information specifically on what you want to do with a triggered pulse. However this example program might give you some hints as well.
Regards
JamesC
NIUK and Ireland

Changing the chart axis step

Hi all,
i have a chart with some dates in axis X, values of money in axis Y. My dates not having the same step. Example: 01/10/2008, 01/11/2008, 02/25/2008, 03/01/2008 etc...
I need to change the step of my axis X (like a day) for having spaces between dates proportional to delta time.
How I can alter the step of my axis X?
Thank you all.

You'll have to union on a query that returns all dates and a zero measure (or you could try null) but it isn't very pretty. Rumor has it a future edition of OBIEE will be 'continuous time aware' ...

How does Pulse Params Vi determine pulse width

I need to know how the PulseParams vi calculate pulse width, rise/fall time? Is it based on the standard 10/90 method or something else? How does it determine what is a "valid" pulse? What is the "Delay" parameter and how do you use it?

Hello Lancer,
The following is taken from LabVIEW Help under Pulse Parameters:
X is the input sequence. X must meet the following conditions:
� The number of samples in X must be greater than or equal to 3.
� X should have a rising edge, a plateau, and a falling edge.
� The expected peak noise amplitude must be less than 50% of the expected amplitude.
If the number of samples in X is less than 3, the VI sets all the pulse parameters to NaN and returns an error. If X does not contain a rising edge, plateau, and falling edge, the VI analyzes the data, assigns values to as many pulse parameters as it can identify, and sets parameters it cannot identify to NaN. The VI does not report this condition as an error.
Note X can be a positive- or negative-going pulse. A histogram is used to determine top and base. If the difference between top and base is negative, the pulse is considered negative-going with a negative amplitude.
If the data in X is noisy beyond the expected 50% amplitude, the VI does not have enough information to differentiate between glitches and pulse data and may assign incorrect values to the pulse parameters. Because it cannot be detected, the VI does not report this condition as an error.
Note If the data is noisy, you can apply a median filter to the data before passing it to the Pulse Parameters VI. Refer to Noisy Pulse Analyzed with a Median Filter for more information about analysis with a median filter.
Note When the X data is a constant value c, the VI sets the pulse parameters to the following values.
amplitude = overshoot = undershoot = delay = duration = 0.
top = base = c.
risetime = falltime = slew rate = NaN.
slew rate is the ratio between (90% amplitude - 10% amplitude) and the risetime.
overshoot is the difference between the maximum value in the pulse and the topline.
risetime is the time required to rise from 10% amplitude to 90% amplitude on the rising edge of the pulse.
top is the line that best represents the values when the pulse is active, high, or on. For a negative-going pulse, top is less than base and results in a negative amplitude. For a positive-going pulse, top is larger than base and results in a positive amplitude.
amplitude is the difference between top and base.
base is the line that best represents the values when the pulse is inactive, low, or off and is the level closest to zero. For a negative-going pulse, base is larger than top and results in a negative amplitude. For a positive-going pulse, base is less than top and results in a positive amplitude.
undershoot is the difference between the baseline and the minimum value in the pulse.
error returns any error or warning from the VI. You can wire error to the Error Cluster From Error Code VI to convert the error code or warning into an error cluster.
falltime is the time required to fall from 90% amplitude to 10% amplitude on the falling edge of the pulse.
duration is the difference between the falling edge time and the rising edge time at which 50% amplitude occurs.
delay is the difference between the time origin and the time at which 50% amplitude occurs on the rising edge of the pulse.
Pulse Parameters Details
Note The Cycle Average and RMS, Transition Measurements, Pulse Measurements, and Amplitude and Levels VIs provide more measurements than the Pulse Parameters VI, and you can configure each of those VIs.
The waveform-related parameters are slew rate, overshoot, topline (top), amplitude, baseline (base), and undershoot. If y-axis units are volts, then slew rate has units of volts per sample. The time-related parameters are risetime, falltime, duration (width), and delay and are expressed in units of samples.
Note The VI assumes the input pulse or pulse train has a bimodal, or two-state, distribution. Any input other than a bimodal input can lead to inconsistent results.
The Pulse Parameters VI uses the following steps to calculate the output parameters.
1. Find the maximum and minimum values in the input sequence X.
2. Generate the histogram of the pulse with 1% range resolution.
3. Determine the upper and lower modes to establish the top and base values.
4. Find the overshoot, amplitude, and undershoot from top, base, maximum, and minimum values.
5. Scans X and determines the slew rate, risetime, falltime, duration, and delay.
The Pulse Parameters VI interpolates duration and delay to obtain a more accurate result not only of duration and delay but also of slew rate, risetime, and falltime.
If X contains a train of pulses, the Pulse Parameters VI uses the train to determine overshoot, top, amplitude, base, and undershoot but uses only the first pulse in the train to establish slew rate, risetime, falltime, duration, and delay.
Note Because pulses commonly occur in the negative direction, the Pulse Parameters VI can discriminate between positive and negative pulses and can analyze the X sequence correctly. You do not need to preprocess the sequence before analyzing it.
If none of these suggestions help, or if I�m not correctly understanding your issue, please post the software and versions you are using, the applicable portions of your code, and any other information that may help, and I�ll be happy to look further into it.
Have a nice day!
Robert M
Applications Engineer
National Instruments
Robert Mortensen
Software Engineer
National Instruments

Using pulse width modulated signal (square wave) to control when a signal is turned on or off

Using pulse width modulated signal (square wave) to control when a signal is turned on or off
Greetings All
I'm trying to use a labview created pulse width modulated signal (square wave) to control when a signal is turned on or off.
Here's my logic and graphic example:
1) The source wave signal is continuous
2) Use a PWM (square wave) created in labview to control when the signal is turned on or off
3) If PWM signal (amplitude) is greater than 0 play signal if PWM is not greater than 0 don't play signal.
I'm actually using this to step sequence / pulse several separate magnetic coils using my audio card (which has several audio output channels), I have a signal in labview played constantly. Than compare it to the PWM (square wave) which controls if the signal gets played on each separate channel or not. That way I can control which coil is on and off and in what sequence they are activated.
I couldn't find an edge detection for a square wave created in labview so I tried Limits but that doesn't seem to work unless I change the phase manually and that only goes from 1 to -1. I'm just trying to compare the PWM (square wave edges) already created by labview / play a signal if the pulse is greater than 0 and it turns off the signal if it's less than 0.
Should I be doing this another way
Tia
Message Edited by sal22 on 08-16-2009 06:09 PM
Message Edited by sal22 on 08-16-2009 06:10 PM
Solved!
Go to Solution.
Attachments:
PWM control signal block.png ‏23 KB
PWM control signal front.png ‏48 KB
pwm test.vi ‏36 KB

Greetings,
I tried it two ways using amplitude and levels and fft spectrum. The values don't seem to update the way I need them to (basiclly showing a 0 or a 1). I compare the Y values like you recommended but they don't ever seem to update.
tia
Message Edited by sal22 on 08-19-2009 10:05 AM
Attachments:
pwm magnitude not updating.png ‏29 KB
pwm test.vi ‏41 KB

NI6602 pulse width measurement: Do I have to use an external sample clock?

Hi
In the .NET 4 example 'MeasPulseWidthBuf_SmplClk_Cont' it is stated in the comments that:
An external sample clock must be used.
Counters do not have an internal sample clock available. You can use
the Gen Dig Pulse Train-Continuous example to generate a pulse train on
another counter and connect it to the Sample Clock Source you are using
in this example.
I have an application running without specifying an external clock. The applications is running, but I'm not sure I can trust the recorded data. Here is the channel creation code:
   task.CIChannels.CreatePulseWidthChannel(readTaskCounter,
   "ReadPulswidthTask", 25e-9, 20e-6,
   CIPulseWidthStartingEdge.Rising,
CIPulseWidthUnits.Seconds);
task.CIChannels.All.DataTransferMechanism = CIDataTransferMechanism.Dma;
   task.Stream.Timeout = callbackTimeoutInMilliSeconds;
task.Stream.Buffer.InputBufferSize = 50000;
   task.SynchronizeCallbacks = true;
   task.Timing.ConfigureImplicit(SampleQuantityMode.ContinuousSamples);
   task.Control(TaskAction.Verify);
Note that I'm not specifying any external clock.
1) Which clock is the daq using? -It is obviously using some clock since I can collect data via this task.
2) Do I need to change the configuration to use an external clock to achieve reliable readings - as mentioned in the 'MeasPulseWidthBuf_SmplClk_Cont' example?
/mola
Solved!
Go to Solution.

Hi mola,
That specific example is for sample-clocked pulse width measurements. This type of measurement is only supported on newer hardware such as X Series boards and will not run on the 6602.
Your application that you linked uses Implicit timing, meaning that the signal itself serves as the sample clock. That is, at the end of each pulse width that you measure, the sample is deterministically latched in. So, you end up with a buffered array of every pulse width that is seen by the counter.
Best Regards,
John Passiak

How can I configure the CTR 1 GATE to output a pulse (10us long) and then immediately take a pulse width measurement?

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 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.htm) ) 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/13555)
Hope that helps
Tim Matthews
NI (UK)

Finite pulse train with variable pulse widths

Greetings LabVIEW developers,
Does anyone have code that can show me how to use E-series counters to generate a finite pulse train where the individual pulse widths vary? I need to generate a series of 20 pulses with the high time for each pulse randomly varying between 50 and 1000 microseconds. The low time for each pulse needs to be constant (around 50 microseconds).
Thanks,
Ryan Wright

Ryan,
Sorry, but this isn't possible with the counter/timers. I've been wanting this capability myself for about 6 years now.
Personally, I think it's an unfortunate "hole" in product capability. The other major data acq hw allows you to capture and later replicate a signal of interest. You can capture an analog waveform with AI and later play it back with AO. You can capture a digital pattern and later play it back with timed DIO. You can capture buffered semi-periods with a counter -- but you can't play play them back later. So for your app, you'll need to generate the variable freq using timed DIO. The new M-series boards ought to work for this, or a dedicated high-speed digital board.
There's another product that I think is even better for timed DIO though and it's put out by one of NI's "Alliance partners" -- Viewpoint systems. Here's an example of why I like it. Let's say you need to generate 20 pulses within 60 seconds. The times of the pulses need to be precise to within 1 usec, and they have no common divisors. The NI method will require you to use an update rate of 1 MHz and you'll create a buffer of 60 MB to represent the digital pattern at every usec. The Viewpoint method needs a buffer of 40 entries. Each entry is a combination of a timestamp and a pattern to generate at that timestamp. That pattern will just stay there until the next defined timestamp. So all you do is define the digital pattern at the instants when one or more bits will change. It works analogously for digital input - if you capture with 1 usec resolution for 1 minute but there are only 20 pulses (40 digital transitions), you only capture the 40 relevant timestamps & patterns instead of a full 60 MB.
If interested, look for the PCI-DIO64 at Viewpoint's website.
-Kevin P.

Pulse width measurement with FieldPoint CTR-502

I would like to measure the pulse width of a signal (ranging from 10 ms to
400 ms out of a signal with period width of about 1 second). I would like to
use a fieldpoint counter module FP-CTR-502. I could find examples on how to
measure frequency but I did not know how to alter it in order to obtain the
pulse width.
Thanks,
Martien

To measure pulse width of a fixed-period signal, you only need to use one counter, so the configuration and program would be different than the frequency measurement example. Set the count source for counter 0 to "32kHz Reference" and the gate source (and wire your signal) to "Gate Input 0." You'll also need to create a control channel to reset counter 0 (as described in the frequency example).
Your LabVIEW program should run as follows:
- When Gate Input 0 becomes true, do nothing
- When Gate Input 0 becomes false again, read then reset counter 0
- repeat
You can use FP Advise to wait for the gate to change (just like the frequency example).
Once you have the number of counts, you can divide that by the frequency (32 kHz) to calculate the "on tim
e" (pulse width) of your signal.
Regards,
Michael Shasteen
Applications Engineering
National Instruments
www.ni.com/ask
1-866-ASK-MY-NI

How can I make the marker event pulse width longer in NI-FGEN?

I want to generate a marker event on PF0 line using NI-FGEN.I can set the marker event pulse width but when I was trying to make the pulse width units as 65 I was getting an error-1074115931.
How can I make the marker event pulse width longer without using script as I am using PXI-5412 which is not supporting Script.
Can anyone help me out in doing the same?

Unforunately, as you mentioned, the PXI-5412 does not support scripting mode. This will limit you to 1 marker using sequence mode. However, the PXI-5421 and PXI-5422 would allow the functionality.
As far as making the pulse width longer, and as the KnowledgeBase Article that you linked to discusses, I don't think it will be possible to create a marker as long as 1us - 10ms using just the Marker properties and without using scripting. You can still try to do this with property nodes and see if you can get a usable result. Start with an example such as "Fgen Arb Waveform Marker" and use the "Marker Position" value to set the start time (you would want 0 here it looks like), and then "Marker Event Pulse Width Value" to change the pulse length, but again I am afraid you will probably reach the maximum of 640 ns here. If you're not able to get this going with the property node, you will need either a FGEN card that supports scripting or another card that does Digital I/O to accomplish this.
Thanks!
Stephanie S.
Application Engineer
National Instruments

Wiring hardware for pulse width measurement

I am in difficulty.even with so simple pulse width measurement.
I am using labview 7.1, DAQmx, MAX, PCI - 6220.
I cannot find help document as to how to measure PW measurement and I find no connection diagram in MAX for using pulse width measurement.
I connect to PFI 9 (Gate) to 5V via switch. What about timebase counter as source? Ok I wanted to use internal clock from PCI-6220. But I cannot get to measure PW.
I want to MAX to measure. Once it is ok, then I will build a simple vi to understand its working better.
Pls help.

Hello,
LabVIEW has examples that are located in the Example Finder under the Help menu inside of LabVIEW. The examples specific to pulse width measurement are organized and located under the Browse tab of the Example Finder under the folders <Hardware Input & Output> <DAQmx> <Counter Measurements> <Period & Pulse Width>. The Example Finder has an information section that has information on the Description, Instructions for Running, Block Diagram Steps, and I/O Connections Overview. The last section will help with the connections. The input for the example titled Meas Pulse Width – Buffered –Cont.vi will be the gate of the counter specified in the “Counter(s)” control on the front panel … such as Dev1/Ctr0. So on your device the 6220, counter 0 gate is PFI 9 as you mentioned.
I understand that you are interested in getting started with the Test Panel in MAX first. The Test Panels are limited to Pulse Train Generation for counter output and Count Edges for counter input. Please use the Count Edges if you are interested in testing the device with a counter input task. However, the Count Edges will just be counting edges of the signal specified in “Edge Source”.
I also understand you are interested in using the internal clock from the 6220. The example I previously suggested uses a DAQmx Timing.vi to configure the duration of the task … for example finite or continuous. The Timing is set to implicit, since the signal wired into the gate of the counter is in fact controlling the timing. The source of the counter task for pulse width is the internal timebase when using DAQmx Timing (Implicit).
“Create a Counter Input channel to Pulse Width. It is important to set the Maximum and Minimum Values of your unknown pulse width as accurately as possible so the best internal timebase can be chosen to minimize measurement error. The default values specify a range that can be measured by the counter using the 20MhzTimebase.” - from the description of the Block Diagram notes on the example. I also link helpful KnowledgeBase below.
AE KB 2X6CMDDS: What Does Implicit Mean in the DAQmx Timing VI?
http://digital.ni.com/public.nsf/allkb/2B6477E3A9B7C07386256D1F0066FBDD?OpenDocument
Samantha
National Instruments
Applications Engineer

Pulse Width Measurement

Hello Friends,
I am new to Labview. And now I am working on a project where I have to measure the pulse width.
I have attached a pulse waveform and would like to measure the pulse width of the first rising the falling edge and log it , rest of the signal I am not interesed in.
I will have this signal 6 times on my digital/analog input.
Can someone help me with the pulse width measurements.
Thank you.
Kind Regards,
Attachments:
Pulse width.PNG ‏60 KB

I get this pulse ( as in picture attached), I want to get it on analog or digital pins in such a way in get the pulse width of only 1st edge.
And this 1st edge lenght is different then the rest that follows. I would like to have the pulse width for only the 1st edge and log the width.
And similarly this signal will come from 5 more different sources. So each signal is different.
For now i connected it to AI0 and I can see the signal.
1) next step measure only the first edge.
2) 6X input channel
2) log it.
Attachments:
Pulse width.PNG ‏60 KB

Change axis step pulse width - NI 7340

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