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).
Thanks in advance,
Saraydin

Oops just occured to me that you are using a 6009 which is not very fast, 48ks/sec, this will not get you very much time resolution and you could have issues seeing much of a 50 us sample. Another approach is to use the counter but you would have to preprocess the spikes to generate a trigger for the counter.
Paul
Paul Falkenstein
Coleman Technologies Inc.
CLA, CPI, AIA-Vision
Labview 4.0- 2013, RT, Vision, FPGA

Similar Messages

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 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 phase difference of two input signal?

Hello,
I'm trying to measure the phase difference of two input sine waves with the
same frequency.
Is there anybody how I can do this with labview?
Thanks,
Dae-han

This is my case! I have TDS3034 which can measure phase. However when I open Read Waveform Measurement vi that comes with tkds30xx.llb, I have a number of options under "measurement function" but not the phase measurement. May be I need another vi to do this?

How can i measure the time between a pulse output and a pulse back on the input?

Llo,
I have a problem i use a ultrsonic sensor, and when i send a pulse out of 4V then a couple of ms i have a pulse back on the input, how can i exactly know how much time there is between the 2 ^pulse??

Use the output pulse to trigger a counter in period measuring mode and stop the counter on the return signal (if the input return signal is large enough to reliably trigger a logic circuit). If the signal is not large enough to trigger the counter directly, an external comparator can be used to generate the stop signal.
Another approach is to use two channels of analog input. Feed the output signal to one of them and the return signal to the other channel. The time between outgoing and return pulses can be determined from the sampling rate. If precise timing is required and your AI board does not have simultaneous sampling, you have to account for the inter-channel time as well.
Lynn

How can i compute the time elapsed between two pulses or the period of an encoder signal if I dont have a constant rpm?

I need to compute the rpm of an engine using information from an optical encoder attached to it. the engine is running in transient mode so the encoder pulse doesnt have a constant frequency. I need to get the period betwwen two rising or falling edges using DAQmx.
Any ideas?

Using an M Series or TIO device you can measure the period between two edges (on two different signals) using the two edge separation measurement. I'm assuming that you don't want to use position measurement because the frequency is varying so much? If not, you may be able to set the sample clock period short enough that you get a decent average RPM measurement.
gus....

How to calculate the Time difference between 2 dates

HI All,
I am using HR_hk_diff_btw_2_dates to calculate the employee service dates.
For that i am inputing his hire date and Term dates and Output format as '05' i am getting output perfectly....
But problem is whe i am inputting the employee hire date is Dec 1 2007 and Term date is
March 31 2009 It is coming as 1 year 3 months 31 days instead of 1 year 4 months directly .......How could we make it make last date also working day and get the O/p as 1 year 4 months ?Please Advice..
Regard
sas

1. FM for difference betwwen two times:SCOV_TIME_DIFF
Import parameters               Value
IM_DATE1                        2008-01-01
IM_DATE2                        2008-01-01
IM_TIME1                        10:00:00
IM_TIME2                        11:30:00
Export parameters               Value
EX_DAYS                         0
EX_TIME                         01:30:00
2. SD_CALC_DURATION_FROM_DATETIME : Finds the difference between two date/time and report the difference in hours
L_MC_TIME_DIFFERENCE : Finds the time difference between two date/time

How can I determine the time zone the computer it set to?

How can I determine the time zone the computer it set to?
I am using Lab View 5.1.1

Hi,
in the G-tools (http://www.geocities.com/gzou999/index.html ) you find two
time functions, "Get local time" and "get sys time". The difference between
them is the time zone.
Niko

How can I measure the hertz in a wave form?

How can I measure the hertz in a wave form?

As an example, this is from BBC Technical Requirements for HD material:
3.1.1 Stereo line-up tones
All stereo tracks must use EBU 1KHz tone (left ident). All tones must be sinusoidal, free of distortion and phase coherent between channels.
Digital Audio Reference level is defined as 18dB below the maximum coding value (-18dBFS) as per EBU recommended practice R68.
See also:
http://www.bbc.co.uk/guidelines/dq/pdf/tv/tv_delivery_to_network_programmes_v1.2-2011.pdf
for full document.
And for BBC Radio:
Not every Network requires tone. Check the delivery requirements with the commissioning network or click here.
Reference tone, where used, should be at -18dBFS or PPM 4 on A, B and/or M.
If submitting material with reference tone, tone and programme material must be have been monitored and measured through the same technical chain. The level of the tone must be equivalent to 0dBu and no less than 8dB below peak audio level for the programme material.
THE LEVEL OF TONE MUST HAVE A KNOWN RELATIONSHIP WITH THE LEVEL OF THE PROGRAMME MATERIAL AND THIS MUST BE STATED; for example: “Tone at 8dB below peak programme level”.
As a newcomer to digital sound (my background is camera) I confess to being somewhat confused. We are normally told to record at the highest level possible. So for voice podcasts I tend to record at about -6dB below peak for maximum volume, distributeds on MP3 files.
But I can underatand that televison and radio especially for analogue transmission) may have limited headroom, hence the requirement for -18dB peak = 0dBM.
I remember when we first rented out Digital Betacam cameras, some recordists were recording almost everything OVER -18dBM.
I suspect that until we have an all-digital world, these requiremnents will still be in place.
Many thanks to all. It's a ghreat community!
Brian Rose

How can I put a time delay between specific events in a while loop?

How can I put a time delay between specific events within the same while loop? I'm already using the "wait" command to control the overall loop iteration speed. But I want to time the individual events as well.

Hi Jesse,
You can use a flat sequence. In each box you can put your individual events and attached wait.
Don't forget to reduce your total loop time of the time you added in the individual sequences.
Doc-Doc
Doc-Doc
http://www.machinevision.ch
http://visionindustrielle.ch
Please take time to rate this answer

Can anyone explain the main differences between CRM 2007 and CRM 7?.

Can anyone explain the main differences between CRM 2007 and CRM 7?.
Does CRM 2007 use the WebUI?.
Jason

My fault for not putting my question forward correctly.
I have worked with CRM 7 a few times now, but my experience has jumped me from CRM 5 straight to CRM 7, having never touched CRM 2007.
I now have an opening to work on CRM 2007 so I was intrigued to know what it physically looked like. I assume it does not use the WebUI interface?.
Jas

How Can I Restrict the times my BT Homehub 2.0 is ...

How Can I Restrict the times my BT Homehub 2.0 is used?
i want to make sure that the kids dont go back online on their wireless laptops after i have gone to bed!!!
how can i restrict the useage times (say 11am - 11pm) for the hub/individual users - WITHOUT taking the plug out when I go to bed!!!
thanks in advance
Paul

belial wrote:
@meaga-byte: the second of those two options can be achieved by using the "BT Powersave" function. This does mean that *everyone* will lose wifi accessibility, so no watching iPlayer be for _you_ drift off! PowerSave will turn all your wifi off and back on between particular times.
This seems a more user friendly option for thoes who are not ofay with IP addresses etc.
Unless Paul wants to use wifi while in bed
If I've helped, just click the Star - Every little bit helps
If you can't fix it with a hammer, you've got an electrical problem.

How can i measure the speed of the fan in sound and vibration signal simulator box

how can i measure the speed of the fan in sound and vibration signal simulator box
provided the values tach out:2 pulses/revolution and maximum speed = 6000rpm

Hi. I tried your suggestion and I could not get it to work well. In
fact it worked better without the running average (which suprised me).
I also played with the number of data points but still could not get it
to work well.
Do you have any other suggestions on how I could sort this problem out?
I
have attached a screen shot of the signal. To recap, I'm trying to
measure the'y' position of the flat regions of the signal. The signal
does not have a constant level, so this 'y' position varies with time
in a non-unform manner.
I am currently differentiating
the signal and selecting the y position when the differential is equal
to zero (within a tolerance band).
In the screenshot, the
signal has been zeroed using the method I have described above.
However, it occasionally has glitches which may be caused when the code
picks up a zero gradient at a peak or valley in the signal.
I therefore need some kind of algorithm that only measures the position of the flat regions.
Many thanks
John
Attachments:
screenshot.gif ‏121 KB

I have just installed a 2TB time capsule on my iMac i7, it see my second 1TB hard drive but the 256 SSD doesn't come up in the list of hard drives I can back up. How can I enable the time machine to see my first SSD 256gb hard drive?

I have just installed a 2TB time capsule on my iMac i7, it see my second 1TB hard drive but the 256 SSD doesn't come up in the list of hard drives I can back up. How can I enable the time machine to see my first SSD 256gb hard drive?

iLife is preinstalled on all the Macs. If you purchased iLife in the App Store or your computer came without DVDs, open App Store > Purchases and download the applications. If your Mac came with discs, insert the Applications DVD and install iLife applications

How can I measure the time difference between spikes (interspik​e intervals)

Similar Messages

Maybe you are looking for

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