PWM on standard output

[RJGats]

Hi All

I am using a NI USB-6211, and I have already used the two counters to do PWM in my project. I have a need to do one more that does not need tight control.  Does anyone have code to use a standard output, not a counter, for PWM control?

Thanks

Bob

[nathand · Accepted solution]

Try the "Square Wave PtByPt" VI. I posted an example here that outputs to a chart, which could be easily changed to output to a digital output instead.

[John_P1]

You'll want to use analog output (assuming it is still available) rather than digital output since the 6211 only supports software-timed digital I/O.

Best Regards,

[RJGats]

Sorry both Analog out being used, which is why I am trying to use a digitial out.

[John_P1]

In that case, the closest you could get is to toggle a digital output line with software-timed delays.  It's far from ideal, but I guess depending on what exactly you mean by "does not need tight control", maybe it would be good enough for your application?  I'd be pretty nervous about using this to control anything important though... software timing on Windows isn't terribly consistent (and the added bus latency of USB isn't doing you any favors either).

Best Regards,

[RJGats]

Hi John

I think it will be ok, I just need to control a stirrer in a bath to keep the tempeture constant.  The walls of the bath will be controled, the bath is only about 1/2 foot cube.  The operator will put in an RPM but it does not have to be real close.

Thanks

Bob

[RJGats]

Thanks nathand

I got the code you gave to work for what I needed.

Thanks again!