how to count total number of cycles of a waveform in labview

[sridhar..reddy]

HELLO..

I am looking for a counter to count total number of cycles .

not like waveform peak detector. In waveform peak detector it will shows us the present graph cycles but not total number of cycles.

i mean if i run test cycles are starting from 1 it should continue untill i stop the test .

i want to know the total number of cycles from starting to end of the test.

[mikeporter]

There is not nearly enough information here to give an exact answer. What is the signal? How fast is it changing?

Mike...

[sridhar..reddy]

simulated signal we can say.....

[natasftw]

What part of "simulated signal we can say" answers either of the two questions posed?

[sridhar..reddy]

check out this vi once.

in this vi i am getting only the current number of cycles.. but i want to have total number of cycles. if a new cycles has over then the cycle count increase by 1.This should happen untill i staop the test.

Kindly suggest me solution .

[natasftw]

The VI didn't attach.

What do you mean by "current" and "total"?  This might be more clear with the VI.  Is total something for a single run of the application or something that should last between runs?  

[sridhar..reddy]

http://forums.ni.com/attachments/ni/170/263391/1/Cycle

check out this link plz...

[sridhar..reddy]

i am not able to attach my vi ..

could you plz help me

[natasftw]

save it as a VI instead of something randomly called cycle

The forums will block unexpected filetypes.

[Hooovahh]

Okay well the attached code was in 8.2 just no extension.  In any case I'd suggest you use one of the Waveform Measurements functions.  There is one to measure a pulse duration, and that will be the time it takes for one cycle of a wave to complete.  With the total time that the wave took place, you can divide and come up with the number of cycles in that time period.  

Or you can do it manually and maybe count the number of times the wave goes from below 5V to above 5V.  If you know your signal is a periodic and should be between 0 and 10 (for example) then knowing the number of crossings in the total time for the wave can also give you the number of cycles.

You are also probably going to want to be careful about a point being greater than the previous point.  If you have a real signal noise on the line may make you bounce back and forth rapidly at the peaks or valleys of your wave.  Which is why in my example I used 5V knowing it is at a point that we should have a steep increase.  But even here with a fast sampling rate may have additional edges.

EDIT:  Here is some quick code that seems to count the cycles.