Why does my waveform not have the right frequency intervals in labview?

问题

In the LabView GUI I set the frequency to 300Hz = 1/300 seconds = 3.333 milliseconds and the pulse width to 2 milliseconds. This computes to a duty cycle of 60%.

Why are intervals between the pulses shown below not equal to 3.333 milliseconds? They look closer to 1 millisecond,which is way off.

Following is a wiring diagram I am using:

Is it possible the problem is my timed loop being set to loop every second? Should I loop faster? What kind of a loop should I be using?

回答1:

You have a pulse rise every 3.333 ms, so that's fine. You don't need a timed loop, the express VI will maintain phase, just make sure it runs more often than the amount of data the express VI produces. A simple wait ms will do.

来源：https://stackoverflow.com/questions/15776538/why-does-my-waveform-not-have-the-right-frequency-intervals-in-labview