Hi, What I want to do: I need to output a PWM signal with varying frequency and duty cycle using DAQ assistant to a card with digital out. The max frequency I should* need is roughly 500 Hz. What's stopping me: I can't figure out how my frequency slider relates to an actual Hz frequency. What's next: Well, I would like a simplified approach to outputting a pwm signal to a digital output on a card or be able to figure out the frequency/timeing/delays out more. I just guessed to get a wave that looked nice on the chart, but I have no idea on what the actual frequency is. (How could I measure it, so I can guess and check to figure out a range I need?) Any modifications to my attached code, or brand new ideas would be great! I am still pretty new to labview so more detail than less is appreciated. Hopefully this makes sense what I'm trying to do. Thank you!

GerdW, This seems to be a lot more accurate. I used the ms timer as my input, so I scaled my frequency input by .001 to make up for the thousand difference on my timer. This seems a lot more accurate. Thanks. Edit: yes its cDAQ by the way.

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LabVIEW

PWM timing issue

Solved!

I am using a NI USB6251 and I want a 50Hz signal on all 4 lines, duty cycle of 20%. This would allow me to pulse 4 LEDs in a desired order.

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Hi,

yes, you can output PWM signals on DO pins. They support hardware timing with upto 1MHz clock, so you just use them to output digital waveforms representing your PWM signal...

Best regards,
GerdW

using LV2016/2019/2021 on Win10/11+cRIO, TestStand2016/2019

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LabVIEW

PWM timing issue

Re: PWM timing issue

Re: PWM timing issue