NI 9401 pulse width measurement.

Similar Questions

• How can I use two counters simultaneously to pulse width measurment

  Hello, everyone!

  I'm new to Labview. I currently have some cDAQ9171 and width measurment with 9401 impulses. My understanding is that the 9401 was 4 meters, which means that I can use these meter separately. However I have the following problem.

  1. I use ctr 0 and ctr 1 (PFI 1 and PFI5) to measure two different impulses. However, it seems that there is an interference between two counters. How can I make two counters working simultaneously and separately?

  2. I first try a pulse width measurment counter in Labview signalExpress. My pulse width is about 0.4ms. However, I can't get the right result, if I choose the starting edge is on the rise (the results always around 20ns. Only if I revise my pulse and pick the starting edge is down, I can get reliable results.

  I'm confused about these issues for about 3 weeks... Is there someone can help what can I do with that?

  I have attached a simple vi...

  Thank you very much!

  
  

• with pulse width measurement external sample clock

  Hi all

  I use a NI 6220 (programming with ANSI C) Board and I would like to make a "unique pulse width measurement' by using a signal from the outer door and an external signal source.

  The program and the card with the help of the "DAQmxCreateCIPulseWidthChan" command works only partially as expected. Namely, the outer door has worked, but the map uses the internal time of 80 MHz base signal instead of the external source connected to the source by default PIN (PFI, 8).

  I tried send an another PIN PFI on the default source pin using the command 'DAQmxConnectTerms', but this did not help either.

  Obviously, I'm missing something...

  Best, Uli

  Hi Uli,

  I posted in your thread here.

  Best regards

• single pulse width measurement

  Hello

  I'm trying to measure the duration of a single pulse using ctr0 on an SMU-6361.

  The signal in the attachment Capture7.jpg, goes PFI 9, ctr0 door.

  The problem is that the counter see ' s the front up and stops. The pulse width is not given as can be seen in the output (Capture8.jpg).

  I get the same results by using Meas_Pulse_Width.vi example.

  Is something wrong with my SMU-6361?

  Oh, I think I know what it is.

  Change the task "pulse width" (a single pulse of height) instead of "Pulse" (the high and low time of a pulse repetition measures).  Change the DAQmx Read to use Ctr > single sample > DBL (instead of pulse).  Change the property filter node digital to use the corresponding properties of the "pulse width" (the filter is still necessary):

  

  The task of the pulse was not period initially because you receive a series of noise pulse repetition (and so it was a very low period).  With the filter, this time since the noise disappears now and the single pulse did not finish measuring the pulse (which requires a high and some time):

  

  For the record, I agree that it is confusing that there is the "pulse" and "Pulse" measure and they do different things.

  Best regards

• signal level for pulse width measurement

  Hello

  I am able the pulse width with the meter M6251 (CI pulse width)

  

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

  Can you say exactly in which the level of signal pulse width is measured?

  Thank you

  Ralf

  In fact, the transition from low to high (or vice versa) is located in between 0.8V and 2.2V.  It is not specced exactly where it will be (although you'd be able to get a better idea, if you have an analog source, you can slowly increase until you see line status change).

  This is why the fast rise time are important to accurately measure the digital signals.

  Best regards

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

  Hello

  In the example .NET 4 "MeasPulseWidthBuf_SmplClk_Cont", it is said in the comments that:

  An external sample clock should be used.

  Hi mola.

  This specific example measures of sample-clocked pulse width.  This type of measure is supported only on new hardware such as the X series cards and will not run on the 6602.

  Your application that you have linked uses Implicit timing, which means that the signal is using the sample clock.  In other words, at the end of each pulse duration which can be measured, the sample is deterministic locked in.  So you end up with a table in the buffer of each pulse width which is seen by the meter.

  Best regards

• sampling frequency of DAQ assistant for pulse width measurment

  Hi all. I want to measure the pulse width of a digital signal of about 1 kHz, via digital DAQ vi assistand pulse width. I need to measure the pulse width approximately 100 Hz.

  I put 1 sample on request and in one of the other method of as implicit synchronization for continuous measures that I met at the error. He doesn't let me frustrating that I could not measure a measurand jut at 100 hz.

  I use Daqmx and windows 7 sp1 and labview 2012.

  Thank you

  OK I have the solution, it's better to see the example and do not use daq assistand and use the primary functions.

  Counter-read Pulseand width and frequency .vi (continuous)

• Full range of pulse width measurement

  Hello

  I'm having a problem with the measurement of PW, I need to read an operating cycle within a range of 0% to 100%.  The problem I have is the signal does not cross the Middle time enough baseline to measure or the histogram cannot be used because the amplitude is zero.  Yes, this is obvious, because there is no pulse, that's basically all true or all false these two extremes, but the pulse measurement vi cannot handle this.  Is there another way, I could measure the market factor, so that I can see if there is a hollow (0%) or high (100%) and everything in-between without errors?  Even when I measure the PulseWidth in the method of the Ridge, rather than the histogram method, which gives me more time to remain at 0 or 100% before it gives an error, the measure see the signal as duty cycle 50% (still a times obvious because it is neither salvation nor low for any length).  So if I could still read 0% or 100% error free, how would I be able to block the two extremes of the never read?  My entry is the acquisition of data, so I can't just 'limit' my input to the source signal...

  Any suggestions?

  Thank you

  -Corbin

  Hey, Henrik, thanks for the reply,

  I didn't really know how to integrage over a period of time in LabView, and I read a wave of digital squares (duty cycle).  I found that I needed to omit extreme values such as 0% and 100%, so I couldn't find a way to do this with one under VI.  What I found is my solution: I knew that + 12V has to be 100%, and 0 v is expected to be low, so I just used 'Amplitude and level measurements' sub VI read the RMS value, used a table that I recorded correspondence (via MatLab help), and I have more problems with errors due to levels of reference of histogram (do not use histogram now...).  My application can read everything from 0% to 100% and he returned my correct data after handling.  Success!

  He could go about resolving the issue differently, but it works.

  -Corbin

• pulse width of measurement of signals generated by data acquisition

  Finally, I would like to:
  Start a counter pulse width measurement and the analog output at the same instant.
  Stop the measurement with an external digital signal pulse width.

  My current plan is to use a digital output on the acquisition of data to synchronize a digital input and the start-up of the meter input.  The digital input will be a trigger to start for the analog output.  This works, except for the meter.

  While trying to implement this, I tried a simple test to generate a digital pulse with the acquisition of data and wiring for counter inputs.  It does not, even if it seems perfect to an oscilloscope.  Then, without changing the software at all, I connect a function generator to my counter entries, and it measures pulse flawless widths.

  I'm actually implemented it with a Python wrapper around the C DAQmx API, but I recreated in LabVIEW, and it has the same.  VI attached.  I have the latest drivers DAQmx.

  Accidentally, I posted this in a forum for LabVIEW, as I managed to post with the account of a colleague.  I think 2 ups live as this mandate to another post.  I'm sorry.  Former post is http://forums.ni.com/ni/board/message?board.id=170&message.id=389856.

  Solution: I had to set the channel to counter with implicit synchronization.  In addition, the sampsPerChanToAcquire must be at least 2, if not, there is an error.  I still don't understand why it worked with a source of external impulse, however.

  DAQmxCfgImplicitTiming (task_handle, DAQmx_Val_FiniteSamps, 2)

• -Measurement of the pulse width specifies the timeout?

  I'm trying to set up a simple project of Signal Express that measure the pulse of two separate signal lines width.

  My PCI6224 has two entrances of meter and then run each pulse in the entrance of a meter line, respectively.

  The I set up the express project signal attached, which consists of two simultaneously runnings tasks DAQmxAcquire.  Each of them is set to measure the pulse for one of the pulse width.  I then connect the results for further analysis.

  This configuration works very well from time to time.  The problem arises when the impulses do not arrive quickly enough and the acquisition of the timeout action.  Looks like that has a simple solution - just increase the time-out - but I can't find a single setting around the affects, the time-out!  The time-out period is always 10 seconds, regardless of what I do.

  Can anyone help?

  Thank you.

  Hello rothloup,

  Unfortunately, there is no option to change the time-out Signal Express for a task entry counter.  This has been brought to the attention of our developers.

  Reading a DAQmx LabVIEW VI has a time-out node you can specify the time-out period, even in the tasks of meter.  I suggest you try to implement your system in LabVIEW (if you can).

  Here is a tutorial on how to make PWM in LabVIEW.

  http://www.NI.com/Tutorial/2991/en/

  See you soon,.

• PXI-4072 can measure a pulse width?

  Can I use a pxi-4072 DMM to measure a pulse width? With the help of labview8.6.1 can I get period information and freq but I am interested in duty cycle. Thank you, Kenneth

  Hi Kenoss,

  If you use the PXI-4072 to acquire waveform data, then you can try to use the Measurements.vi impulse to get the duty cycle.

  

  Best regards

  Tony_G

• Pulse or measure of separation of two edge with implicit synchronization in ticks: what about minVal and maxVal?

  When I pulse or measure of separation of two edges, using the implicit synchronization, DAQmx chooses (I think) an internal time base appropriate for the measurement. My X series on Board (a 6320) has for example a time base internal 100 MHz. I think I can apply to the use of a base of specific time (using the Set accessor of property DAQmxSetCICtrTimebaseSrc to set the counter to the value '100MHzTimebase' time base). But the docs of the DAQmxCreateCIPulseChanTicks and DAQmxCreateCITwoEdgeSepChan functions (this last one called with the parameter to the DAQmx_Val_Ticks units) make me spend a minVal and maxVal. Apparently, these values are used to determine a time appropriate for the implied timing base (internally). But how to choose the specific digraph/maxVal values? They are obviously dependent on the time base, so it's kind of a situation / the hen's egg. Should I just say '1' or '0.1' or even '0 '? Because I * want * the time of 100 MHz, to use base. Or can I simply call the DAQmxSetCICtrTimebaseSrc after DAQmxCreateCIPulseChanTicks?

  1. When you use "Ticks" for units, digraph must be > = 2.  DAQmx does not support measures of 0 or 1 "Tick" of a time value.

  In general, the parameters that minVal and maxVal are mainly useful for people who are measured in scientific units such as seconds.  They allow DAQmx do the dirty work of correlation required range of programming interface with the basics of time available to the Agency and to make a judicious selection automatically.  For people like you measure in ticks, DAQmx won't do the thinking for you anyway, so just give them plausible values.

  2. Thus, maxVal must simply be a valid 32-bit integer.

  3. Yes, you can explicitly configure to use the time base of 100 MHz after the creation of the task, no doubt thanks to the function, you said "DAQmxSetCICtrTimebaseSrc".  (I do my programming in LabVIEW and don't know the syntax of the api code text driver.)

  I believe that if you do not explicitly choose a time base for a task using ticks as units, the Council will use its default time base.  I know there is an api function in LabVIEW to interrogate the database after creating a task, perhaps you have an available too?

  -Kevin P

• Pulse width depends on the number of pulses (pci-6602)

  Hello

  I'm trying to generate samples done with pci-6602.

  I use CO Pulse ticks + implicit options

  External impulses is 1ms 1PPS pulse from the trimble GPS receiver

  If I set the number of pulses = 1, then I had to pulse length (high ticks - 1) =

  If I set the number of pulses > = 2 and low ticks > = 3, then I got pulse length = (high ticks)

  If I set the number of pulses > = 2 and low ticks = 2, then I got last puls width = (high ticks - 1) and all other vegetables dry with length = (high ticks)

  With a single generation pulse width pulse is (high ticks - 1)

  Is there an option to configure the same pulse width for any number of pulses for a train over (N pulse)

  screens to fix

  
  

• Generate PWM signals with 1.5 ms pulse width

  Hi all

  I'm working on a project where I need to generate a PWM with a pulse between 1.3 and 1.7 width ms to order a servo rotation continues.  LabView is in communication with an arduino Uno microcontroller by LINX.  My original plan was to use the milliseconds of wait function in LabVIew to do this.  I put the PIN PWM high, wait 1.3 or 1.4 ms then set the low axis for 20 less ms pulsewidth.  before repeating.  This is how I have gnereate one using the Arduino IDE pulse width, so I thought I'd be able to do something similar here.  However, as I'm sure is already obvious to anyone who reads this, the milliseconds waiting finction in LabView only accepts the whole entries.  Arduino IDE is similar, but there is a delayMicrosecond function that can be used, so if I want 1.4 ms I use 1400 US snf then convert it in ms for the 20 least part.  How can I do something similar in LabView?   Also. When I run the program as what with a 1 ms pulsewidth I have a strange behavior.  It in fact generates a PWM signal, somewhere between 0.75 and 1.25 ms and with a period between 50 and 54 ms, it turns into a model each about half a second.  I'm using LabView 2014.  Any ideas?

  Chris

  You can't get that kind of resolution with Windows and any delay you specify will have considerable jitter due to Windows. If you can pass values with Linx and allows the arduino to control them, stick with that.

• With the help of modulated signal pulse width (square wave) to control when a signal is enabled or disable

  With the help of modulated signal pulse width (square wave) to control when a signal is enabled or disable

  Hello all

  I am using a modulated signal to labview created pulse width (square wave) to control when a signal is activated or not.

  Here is my logic and a concrete example:
  (1) the wave source signal is continuous
  (2) use a PWM (square wave) created in labview to control when the signal is enabled or disabled
  (3) if the PWM (amplitude) signal is superior to 0 play signal PWM is not greater than 0 do not play signal.

  I use actually this to the sequence step / pulse several distinct magnetic coils using my audio card (which has several channels of audio output), I have a signal in labview played constantly.  As to compare it to the PWM (square wave) which controls whether or not the signal is played on each separate channel.  That way I can control which coil is on and offshore and in what order they are activated.

  I couldn't find an edge detection for a square wave created in labview, so I tried the limits, but it doesn't seem to work unless I change the phase manually and it only goes 1-1.  I'm just trying to compare the PWM (edges of the square wave) already created by labview / play a signal if the pulse is greater than 0 and it shuts off the signal, if she is less than 0.

  Should I do this another way

  TIA

  A waveform contains an array of values. You must check every value and respond accordingly: