Error 20308 occurred in labview...

[gaurav024]

A am using pulse measurement block for measuring the ON time period of the signal. I am generating the square wave with inbult block given in the labvview for generating square wave with particular frequency and duty cycle.. But while measuring same signal and running the programme error 20308 is occured. How it can be solved???

[EdGro]

if the signal you input does not contain enough edges to complete the measurement LabVIEW will return this error. In this case, simply raise the frequency or the number of data points of the signal

[gaurav024]

But we can not change our frequency..We are measuring signal  from ultrasonic sensor through crio. Here I attached my problem.

[EdGro]

you can change the frequency by double clicking the express vi.. i changed to 100Hz and it worked fine.
You have to change either the frequency or the sampling rate

[gaurav024]

WE can't change our frequency... Its the output from our sensor..  We are using ultrasonic sensor, so according to distance its generate the signal with on time within 10 micros and off time 30ms.. So we have to measure that on time accurately, so we can determine distance of object from the ultrasonic sensor..

So in our project frequency we can't change. Its written in  sensor specification that it will gives output in very few microsecond pulse, so we want to measure that microsecond pulse width... And pulse measurement block gives that on time period but its not working in low duty cycle, since our frequency is 33.32hz and duty cycle is 0.033%... this much of low duty cycle it cant measure the pulse width..Please suggest some solution regarding this...

[neffk]

I have a similar problem.  I'm measureing the width of a pulse in a pulse train that is very sparse.  That is, the width of the pulse is very very small compared to the spaces between the pulses.

Is there any way to measure the width of a single pulse without resorting to point-by-point methods? 

One possible solution is to concatenate the signal with itself.  Seems like a hack, though.

[neffk]

Oh, use export mode to prevent LV from trying to calculate duty cycle and other stuff that requires periodicity.