Unable to measure pulse time, using Counter pulse time 1samp.vi

Hi
I am using pci6624 board to measure pulse time . I have selected counter 0 to measure pulse time & connect the signal to gate0+ & gate0-.
When i used Counter pulse time 1samp.vi to read the pulse time , i am not able to read the value and i am getting following error msg . If i used Counter DBL 1samp.vi i am getting out put.
Please help me
Attachments:
pulse_time_measurment.vi ‏11 KB
Counter_errors.JPG ‏44 KB

Hi,
You can try changing the mode to counter -> single sample -> DBL in Daqmx read function
You can also try this example 'Meas Pulse Width-Buffered-Cont.vi' or related examples from NI Example Finder.
Cheers,
Sahil Gupta
NI India

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Using counter to time stamp to text file

Dear all,
I am using counter to acquire singnal from quadrature linear encoder. I would like to time stamp the data acquisition to text file but I found that I can't choose to read time. Anyone know how to solve this problem?
Attachment is my program.
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Attachments:
encoder continous 21-4-2013.vi ‏28 KB

Hi,
Have you seen these two articles?
http://digital.ni.com/public.nsf/allkb/68806B93A21355E98625726F0064822B
http://digital.ni.com/public.nsf/allkb/5D42CCB17A70A06686256DBA007C5EEA
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Here is the code :
Calendar cal = Calendar.getInstance();
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Attachments:
Generate delayed Counter Pulse problem part 2.doc ‏108 KB
Generate delayed Counter Pulse Problem part 1.doc ‏25 KB
Generate Counter Pulse.vi ‏153 KB

Andrew,
If you want to start a counter output task based on an analog input you should use an analog trigger (if your device supports analog triggering). Take a look at the example Cont Acq Sample-Timed Loop-Analog Start.vi (in the example finder - search for "trigger") for how to set up an analog trigger in DAQmx. Also, you can use the Start.Delay property in the DAQmx Trigger property node to specify an amount of time to wait after the Start Trigger is received before generating the first sample
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National Instruments

Counting Pulses

my aim is toimplement position control of DC motor,i am using NI USB 6221,to find the position i am using IR LED and Photodtector and an encoder wheel ,in which when light is received it counts as one and if not zero,is it possible for me to count the number of pulses and find the position,ihave only the above hardware resources,plese help me
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Hi,
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Plz give me idea about +ive Time Mgmt with Clock Time.
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When i tried to maintained Infotype 2011 . (from 01.04.2007) record is not created , it gives
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Hi Rajneesh,
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Hi Thaison V,
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How to use Counter/timer PWM Pulse as a trigger to aquire data??

(1) I'm using the NI DAQpad 6015 multi-function card with the new DAQmx Driver. I'm using the counter/timer (counter 0, and counter 1) to generate 2 different PWM pulses to supply my sensor circuit. each pulse is a 1 second in duration. The pulse with 5m.sec duty cycle is the supply for my sensor. In addition to that, I'd like to use the 5 m.sec as a trigger to aquire the sensor reading. The DETECTIN POINT should be the middle of the HIGH State of the 5m.sec pulse (i.e just at the 2.5 m.sec point of the high state).
(2) another point is: how to display the counter/timer pwm output pulses on the front pannel??
Attached is the VI i'm using (Complete PWM.vi)
regards,
Attachments:
Complete PWM.vi ‏49 KB

Hello alaali,
It sounds like what you need is a trigger delay property node. This property node specifies an amount of time to wait after the Start Trigger is received before acquiring or generating the first sample. This value is in the units you specify with Start.DelayUnits. This way you can still acquire using the trigger, and you can specify the delay to be 2.5 ms so that the point that you actually acquire will be 2.5 ms after the trigger.
Hope this helps.
Regards,Message Edited by Raajit L on 04-23-2007 04:34 PM
Raajit L
National Instruments
Attachments:
DAQmx Trigger Delay.jpg ‏6 KB

Generate a pulse train using a count from a quadrature encoder as the clock

I am trying to generate a pulse train with the same frequency as my quadrature encoder. Every time the encoder counts, I want the pulse to go high until the next count and then go low and so on. I am using a 6602 PCI card and a BNC 2121 accessory.

Maybe I'm not understanding your app, but I *think* you and I are approaching it from two very different directions.
As I understand it, you'd like to emit a pulse with each quad state change. Then that pulse would act as a counter Source signal. The counter will then increment on each pulse, to keep track of accumulated position. Further, you'd use your device-under-test (DUT) as a counter Gate signal, which would buffer the position count each time there's a rising edge on your DUT. The end result is a buffer of position values, captured at each rising edge of your DUT.
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I *think* the 6220 should be ok, based on a quick overview of specs. I assume your 3.6 MHz is the rate of ref encoder quad state changes, right? In the approach I'm suggesting, you only need concern yourself with the rate of DUT edges which appear to be in the 10's of kHz or less.
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You may be able to use the Edit Tempo function to work this out. With you waveform in Edit view Right Click on the time scale at bottom of waveform and select Bars and Beats display. Select a number of beats by highlighting with the cursor. Then again on the Time bar select Edit Tempo. In that dialogue you can try clicking on Extract to find the Tempo ie. beats per minute. Also you can try adjusting the tempo by entering avalue manually to see how close that gets to your waveform.
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I am trying to measure speed, and am using the FP-502 counter timer module to count the pulses from my sensor. The field point example that uses a fixed width gate pulse will not work for my appliation because I need a gate pulse so big that it updates way to slow.
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Dan

Hello guys
Thanks for all your sugestions I have the final results. I got it to work but I would like to add some comments for anybody who is trying to attempt this.
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I a
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Hi everyone, bit of a newbie here so please bear with me.
I'm a student at a university conducting a muon decay experiment with an oscilloscope connected to some photomultipliers. To summarize, if a muon enters the detector it will create a very small width pulse (a few ns). Within a period of 10µs it may decay, creating a second pulse. The oscilloscope triggers on the main pulse 5-15 times per second, and a decay event happens roughly 1-2 times per minute. I am trying to collect 10 hours of data (roughly 1500-2000 decay events) and measure the time it takes for each decay.
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Hi wdavis8,
I am not that familiar with Tektronix, but there should be a place in the dialog that you go through when you create the action step to acquire date to specify a sampling rate. That would allow you to reduce the number of data points you are seeing, but may reduce the quality of the data.
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Here is some information about peak detection in LabVIEW:
http://www.ni.com/white-paper/3770/en/
You could also do some downsampling on the data to get fewer data points:
https://decibel.ni.com/content/docs/DOC-23952
https://decibel.ni.com/content/docs/DOC-28976
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Hi
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Hi Gopal,
1) yes the frequency generator is programmable. You have 2 timbebases (10MHz and 100kHz) and you can divide down by any integer between 1-16. Those are the only frequencies you can use.
2) The way counters work is that you can apply a gate signal to the counter which will cutoff the output. Therefore, you can have a second counter generating a pulse train of an equivalent frequency to the frequency generator (fout) but you don't want it to start immediately. You want it to start only after a short delay (equivalent to a 90d phase). Therefore, you need to "gate" or prevent the output on this counter for that small delay period of time. The way you can do this is by using a second counter to create a delayed pulse. You would
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How to use Counter/timer PWM Pulse as a trigger to aquire data??

I posted this question on the Counter/timer BOARD, but i got no replies. So i decided to post it here.
(1) I'm using the NI DAQpad 6015 multi-function card with the DAQmx Driver. I'm using the counter/timer (counter 0, and counter 1) to generate 2 different PWM pulses to supply my sensor circuit. each pulse is a 1 second in duration. The pulse with 5m.sec duty cycle is the supply for my sensor. (Imanaged to generate the required pulses).
In addition to that I'd like to use the 5 m.sec as a trigger to aquire the sensor reading. The DETECTIN POINT should be the middle of the HIGH State of the 5m.sec pulse (i.e just after the 2.5 m.sec point of the high state). Detection takes place only at the HIGH State of the pulse. How Can i read my sensor voltage for this limited duaration (2.5 m.sec) each time the pulse is high.
(2) another point is: how to display the counter/timer pwm output pulses on the front pannel??
Attached is the VI i'm using (Complete PWM.vi), and the pulses diagram
regards,
Attachments:
Complete PWM.vi ‏49 KB
pulse.JPG ‏10 KB

This question has been replied to on this other post.
Thank you,
Raajit L
National Instruments

Unable to measure pulse time, using Counter pulse time 1samp.vi

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