How to measure the time?

i have two buttons. first the user has to press the first button, then he has to press the second one. I want to measure the time between the two clicks? How can I do this?
thx Ingo

The method with the timer will work fine in this case...I thinck that creating a timer with a period of 50-100 miliseconds will do the job(this depends of course on the amount of elapsed time that you generaly expect to pass )...the time error will be less than the period of the timer...Of course,this is in client server..
In web,I thinck you need to use the JAva way...in fact,you can use the java class even in client-server with the java importer...
If you use a java class even in c-s,the results will be very accurate

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How to measure the time a pulse is high for?

I am using Pulse measure.vi to measure the output of a comparator. My comparator output feeds to an LED. The duty cycle is 50% so the LED just flashes on and off. I want to measure the time the output is high ('ON time') and I have been getting this by just multiplying the pulse width measure by the no. of pulses but I want to modify it to measure the 'ON time' of random signals with different duty cycles...
The aim is that I am taking in a signal and need the LED to turn on when the signal 'ON time' reaches a certain specified time.
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Hi PinkLady4218,
You should be able to use one of the shipping examples to do what you need, please open LabVIEW and go to Help >> Find Examples.
From the Example Finder please go to Hardware Input and Output >> DAQmx >> Counter Measurements >> Period or Pulse Width >> Meas Buffered Semi-Period-Continuous.vi
You will then need to deinterleave the output array as it will show high time then low time then high time then ...
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Regards
JamesC
NIUK and Ireland
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How to measure the time of evolution of a signal in a graph and to compare this time measured with a known value?

For my application, I am obliged to measure the time of evolution of a signal acquired (from T1 to t2) by an analogical entry of a module NI 9203, and to compare this value with a value known in order to judge if this time of evolution is correct or not.
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Greetings Jacob,
I am not sure what you mean with 'time of evolution' but normally you acquire at a certain acquisition rate. How much time that has passed, you can calculate by checking how much points are between your two points of interest.
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National Instruments

How to measure the time the cursor hovered over an hot spot

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Regards,
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The solution I came up with has five hotspots. First off a calculation icon: OptionTimes := [0,0]
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How to measure the performance of Extractor

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LabVIEW/SignalExpress: How can I automate measuring the time between two pulses?

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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To conclude, using Labview or SignalExpress, I would like to be able to have the software
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Any help would be GREATLY appreciated, thanks!

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.
If it’s just a matter of that much data being hard to dig through when you have that many points, you could do some analysis on the data after the fact, and then create a new file with only the data you want to look at. For example, you could identify the peaks in the data, and based on the distance between them or the difference in magnitude, selectively write data to a new file.
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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How can we measure the time of excecution of our Java program?

i have a java application program which runs depend upon the user input.
I want to analyze how my application works.
So i want to measure the time of execution.How can i do it?

makpandian wrote:
..i want to measure the time of execution.
long startTime = System.currentTimeMillis()
doTimeConsumingTask();
long endTime = System.currentTimeMillis()
System.out.println( "The task took " + (startTime-endTime)/1000 + " seconds." ); Edit 1:
I see I was 'too slow off the mark' by 5 minutes. ;)
Edited by: AndrewThompson64 on Jul 19, 2009 10:58 PM

How can i measure the time between two successive rising edges ,using digital input ..

Hello
I'm trying to measure the time in seconds between each two successive rising edges on a digital input .
Till now I have managed to detect the rising edge ,increment a counter with each rising edge ,and snap the time at which the rising edge happenned
all I need now is to subtract the current rising edge time from the previous rising edge time in order to calculate (T) which can be 1/frequency and display it in realtime to the user.
but I don't know how to do this
Can somebody please help me !!!
note: the time that I'm measuring ranges between 200 ms - 2 seconds
Solved!
Go to Solution.
Attachments:
Counter without time.vi ‏11 KB

Cheers for that. It's always a good idea to post your SubVIs as well - the problem could be in one of those.
To help you out:
You already know how to use shift registers so why not use one again for time? Create a new shift register for the time then simply compare the "rising edge time" to the the previous time stored in the shift register and then write the new time to the shift register.
Just a few other pointers:
1. You'll want to initialise your shift registers ie wire a constant to the left hand register outside of the loop. This will cause the register to be reset each time the program is run. This is so that your counter will start from zero each time you run your code.
2. You don't need to use the "greater than?" compare function with boolean as they can only be true or false (1 or 0)! The "Equal?" function is what you should use here.
3. Lastly, it's a small thing but you can use the same tunnel that feeds into a case structure in each of the cases - no need to create two tunnels for the true and false cases, use the same one.
-CC
"If anyone needs me, I'll be in the Angry Dome!"

How can I measure the time between each two successive rising edges ,using Digital Input ?

Hello
I'm trying two measure the time in seconds between each two successive rising edges on a digital input .
Till now I have managed to detect the rising edge ,increment a counter with each rising edge ,and snap the time at which the rising edge happenned
all I need now is to subtract the current rising edge time from the previous rising edge time in order to calculate (T) which can be 1/frequency and display it in realtime to the user.
but I don't know how to do this
Can somebody please help me !!!
Solved!
Go to Solution.
Attachments:
Counter without time.vi ‏11 KB

Woah!
Sorry Apok, but your code is becoming way too complicated/messy. I don't think that all of those shift registers or boolean conversion/operators are needed at all.
If you want to measure the timing between two button presses then this is a different (much less complicated) way. It simply records the timing of the button press into a shift register then compares the two.
Spoiler (Highlight to read)
Of course this is a very quick and basic solution just to show you that it can be much simpler than you are making it (remember to use the mechanical actions of the buttons to get the behaviour you want).
A better way would be to use an event structure looking at value changes of the buttons to determine the timings between clicks.
-CC
"If anyone needs me, I'll be in the Angry Dome!"
Attachments:
Time between clicks.vi ‏9 KB

How can I measure the time difference between spikes (interspike intervals)

I have used NI USB-6008 (DAQ) to sample a continous signal, after sampling I compared the amplitude of the resulted signal with a value. If the amplitude is greater than a specific value (threshold) then it can pass. Now I want to measure the time difference between the resulted samples. The samples look like spikes. (May be if I trigger a timer, then I can measuer the time difference, but I have not seen such a timer).
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Paul
Paul Falkenstein
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CLA, CPI, AIA-Vision
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How to measure the baseline of a noisy, pulsed signal

Hi
I am measuring the torque exerted by a large motor on a shaft using a load cell and lever arm. The shaft runs at approx 150 rpm. I have attached a drawing that shows the output I get. This is a test rig.
I have written some code that measures the maximum peak out of a group of approx 5 peaks and writes this to a shift register. This gives me an idea of the maximum torque "spike".
I also wish to measure the baseline torque (due to the bearings in the machine). Even when highly filtered (my noise filter is set to 49Hz) the signal exhibits this noise which is probably due to vibration in the system. The signal is zeroed when the motor is not running.
Does anyone have an ideas on how to measure the "baseline" torque? The large spike in torque prevents me from doing a running average. Can anyone think of a way of averaging just the noisy part of the signal to get an average value? I aim to to subtract the average baseline torque from the peak value to get an idea of the torque due to the event which causes
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Any help would be greatly appreciated.
Many thanks.
Attachments:
drawing of torque signal.gif ‏26 KB

Thanks for the reply. I understand what you are saying. However, I might have to modify my method for measuring the peaks if I choose to implement your idea. I have taken a screenshot of my "peak finder" code and attached it.
Bascially, the reset terminal is wired to a timer which outputs a pulse every few seconds. This resets the vi (a standard NI one I think) and sets the peak magnitude back to zero. This way, I am windowing the signal and measuring the maximum peak in every window. This is what I need to do.
So I could use a logical filter to feed data to the running average only if;
the amplitude of the signal is less than a certain threshold
and if the current value has similar low peaks either side of it
How would you construct the code to delay the evaluation so that the values in front and behind of the current data point can be analysed?
thanks again
Attachments:
peak_find_screenshot.jpg ‏45 KB

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How to measure required time(tic-toc) in a vi?

how to measure required time(like tic-toc in matlab) in a vi?

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Yet another elapsed time.PNG ‏4 KB

How to populate the time component of a cube?

We have a question regarding how to populate the time component of a cube. Let me explain:
We are using OWB 10gR2. We have created a cube with several dimensions. We are now building the mapping to load the cube. The cube operator has two columns for every dimension (e.g., "customer" and "customer_id" for the "customer" dimension).
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Day Level - YYYYMMDD
Month Level - YYYYMM
Week Level - YYYYWW
Quarter - YYYYQ
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Cheers
David

How to measure the time?

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