Frequency of signal and pulse duration varying as to reduce the duty cycle

To sum up my problem, I am creating a period and the controlled voltage pulse sequence, but as I decrease my cyclical report, the distance between each pulse begins to become irregular. More precisely:

I want to have three pulses, each a positive amplitude specified, long, with 23 ms between each 80 microseconds. After these three impulses, I would have a negative pulse of 3 * than amplitude, followed again by Ms. 23 this cycle must be repeated 260 times.

I tried first of all to create the positive impulses to help simulate Signal VI, assigning a square wave with a frequency of 43.327556, an offset of 0.5 and the amplitude of 0.5. And the operating cycle as the default value of 50%, the signal seems to be normal (constant frequency and the duration of each pulse is equal;) "I'm in a position with an oscilloscope).  However, when you set the duty cycle for. 3466%, the time between each pulse varies and some legumes are longer than others. I wrote the data able to file directly from fake Signal VI to ensure that he was not only a problem of scope, but it seemed that writing to a file of measure has not sample enough points for me to accurately measure. Even decrease the market barely 10% factor, I see the question arise already.

So my question is, I'm doing something wrong here? It is a kind offset of Labview to try to perform a duty cycle that small? And are there any alternatives to the way I have this set up? I thought I would try to use a train of pulses instead, but I'm not very familiar with this and I know, you can't control the amplitude of the pulses.

Any help is appreciated! Thank you very much.

My guess is that you are limited by the sample rate. If the difference between the two signals time is less than the sampling period (1 frequency / sampling), you will not be able to generate the signals you want.

Please tell us the sampling rate, you use and the settings that work and those that do not. If your data file is not too big, please post so that we can see some data. Post your VI can help too. Check the default settings before you save the VI.

Lynn

Tags: NI Software

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